UNIT4 UNIT Introducing the Unit 4 - mrwrightsclass.netmrwrightsclass.net/resources/old-7th-grade-text/chap16.pdf · motion of the body’s 68 joints. Her eyes and other sensory organs

What’s Happening Here?A stream of bubbles (left) is the only sign of thisswimmer’s exertion. Yet, a sequence of millions ofevents must occur for her merely to stretch herarms over her head. Electric signals travel alongnerve fibers (shown below, resembling a squiggleof toothpaste) at speeds up to 140 meters persecond to instruct the adjacent skeletal muscle.Food is transformed into energy within hercells. Poised to begin her stroke, she uses theshoulder joint, which has the widest range ofmotion of the body’s 68 joints. Her eyes andother sensory organs help her sense her positionon her back in the water. In this unit, you willlearn about the human body and how its manysystems work together to accomplish even thesimplest of feats.

Explore the Glencoe ScienceWeb Site at www.glencoe.com/sec/science/ca to find out moreabout topics found in this unit.

CONNECTION

NETinter

437

437

Introducing the Unit

What’s happening here?Have students read the text

and examine the pictures.Ask them to name as manybody systems as they can thatare involved in helping theswimmer swim. Ask whichevents described in the bodyare happening without theswimmer’s conscious control.

Content BackgroundThe human brain holds

about a hundred billion nervecells, or neurons. Each neuroncan receive signals from otherneurons. If the net sum ofthese signals tells the neuronto fire, the neuron undergoesa chemical change that allowspositive ions to build up anelectrical charge. This chargetravels down the neuron untilit reaches a gap or synapsebetween it and another nervecell. The electrical signalcauses vesicles in the nervecell to release chemicals intothe gap and the transmissionof signals continues.

Previewing the ChaptersHave students look

through the unit for pho-tographs and illustrationsthat show relationships be-tween body systems, for ex-ample, muscular and skeletal.

Tying to PreviousKnowledge

Have students name organsfrom each of the body sys-tems and tell what they do.

Internet Addresses

Explore the Glencoe Science Web Site at www.glencoe.com/sec/science/ca tofind out more about topics found in this unit.

436 UNIT 4 THE HUMAN BODY

Healthful Habits Have students think ofways they and their family members takecare of each body system. For example, thefamily may eat a low-fat diet to take care ofthe circulatory system. The student maydrink milk to build strong bones.

Science at HomeScience at Home

The Human BodyThis unit describes the sys-

tems of the human body andhow they function. Humandevelopment from concep-tion to birth is discussed. Stu-dents will learn conceptsneeded to make informedhealth choices.

Unit Overview

Chapter 16Bones, Muscles, and Skin 43816-1 The Skeletal System16-2 The Muscular System16-3 Skin

Chapter 17Nutrients and Digestion 46217-1 Nutrition17-2 Your Digestive System

Chapter 18The Circulatory System 49018-1 Circulation18-2 Blood18-3 Your Lymphatic System

Chapter 19Respiration and Excretion 51819-1 The Respiratory

System19-2 The Excretory System

Chapter 20Nervous and Endocrine Systems 54420-1 The Nervous System20-2 The Senses20-3 The Endocrine System

Chapter 21Reproduction and Growth 57021-1 Human Reproduction 21-2 Fertilization to Birth21-3 Development After

Birth

Chapter 22Immunity 59822-1 Communicable Diseases22-2 Your Immune System22-3 Noncommunicable

Disease

44U N I T 44 4U N I T

TheHuman

Body

TheHuman

Body436

http://www.glencoe.com/sec/science/ca


438B

Chapter Review, pp. 31–32Assessment, pp. 61–64Performance Assessment in the Science

Classroom (PASC)MindJogger VideoquizAlternate Assessment in the Science

ClassroomPerformance Assessment, p. 16Chapter Review SoftwareComputer Test Bank

Chapter Organizer

Standards Reproducible Resources Technology

National State/Local

National ContentStandards: UCP4,UCP5, A1, A2, C1

National ContentStandards: A1, A2,B2, C1

National ContentStandards: UCP5,C1, F1

Activity Worksheets, pp. 85–86 Enrichment, p. 45 Laboratory Manual, pp. 89–90 Reinforcement, p. 45 Study Guide, pp. 61-62

Activity Worksheets, pp. 87–89 Enrichment, p. 46 Laboratory Manual, pp. 91–94 Multicultural Connections, pp. 31–32 Reinforcement, p. 46

Activity Worksheets, p. 90 Critical Thinking/Problem Solving, p. 16Enrichment, p. 47 Reinforcement, p. 47 Study Guide, p. 64

Section Focus Transparency 45 Teaching Transparency 31Glencoe Science VoyagesInteractive CD-ROMGlencoe Science VoyagesInteractive Videodisc—LifeThe Infinite Voyage Series

Section Focus Transparency 46 Teaching Transparency 32 Science Integration Transparency 16Glencoe Science VoyagesInteractive Videodisc—Life

Section Focus Transparency 47

Assessment Resources

Level 1 activities should be appropriate for students with learning difficulties.

Level 2 activities should be within the ability range of all students.

Level 3 activities are designed for above-average students.

ELL activities should be within the ability range of English Language Learners.

Cooperative Learning activities are designed for small group work.

These strategies represent student products that can be placed into a best-work portfolio.

Multiple Learning Styles logos, as described on page 63T, are used throughoutto indicate strategies that address different learning styles.

P

COOP LEARN

ELL

L3

L2

L1

The following designations will help you decide which activities are appropriate for your students.

Key to Teaching Strategies

English and Spanish audiocassettes areavailable for use with each section.

Test Practice Workbooks are available foruse with each chapter.

California ScienceContent Standards:5b, 5c, 6h, 7a, 7b,7c, 7d, 7e

California ScienceContent Standards:5b, 5c, 6i, 7a, 7c,7d, 7e

California ScienceContent Standards:5b, 7a, 7b, 7c, 7e

Chapter 16

438A CHAPTER 16 BONES, MUSCLES, AND SKIN

Section Objectives Activities/Features

Activity MaterialsExplore Activities MiniLabs

Chapter 16 Bones, Muscles, and Skin

Chapter Opener

16-1The Skeletal System

3 Sessions11⁄2 Blocks

16-2The Muscular System

2 Sessions1 Block

16-3Skin

1 Session1⁄2 Block

1. Identify the five major functions of theskeletal system.

2. Compare and contrast movable andimmovable joints.

3. Describe the major function of muscles.4. Compare and contrast three types of

muscles.5. Explain how muscle action results in

movement of body parts.

6. Compare and contrast the epidermis anddermis of the skin.

7. List the functions of the skin.8. Discuss how skin protects the body from

disease and how it heals itself.

Explore Activity: Observe Muscle Size, p. 439

Problem Solving: Shape Affects Strength, p. 443

Skill Builder: Interpreting Scientific Illustrations, p. 445

Using Computers, p. 445Activity 16-1: Observing Bones, p. 446

Physics Integration, p. 448Using Math, p. 450MiniLab: Observing Muscle Pairs at Work, p. 451Chemistry Integration, p. 452Skill Builder: Sequencing, p. 452Science Journal, p. 452Activity 16-2: Observing Muscle, p. 453Reading and Writing in Science: Frankenstein,

p. 454

MiniLab: Recognizing Why You Sweat, p. 456Skill Builder: Concept Mapping, p. 457Using Computers, p. 457

p. 439measuring tapes

p. 446beef bones, chicken leg bone, hand lens, paper towels

p. 453prepared slides of smooth, skeletal, and cardiac muscles; microscope; cooked turkey or chicken leg;dissecting pan; 2 dissecting probes; hand lens

p. 451no materials needed

p. 454hand lens, clear plastic bag, tape

The number of recommended single-period sessions The number of recommended blocksOne session and one-half block are allowed for chapter review and assessment.

Need Materials? Contact Science Kit at 1-800-828-7777 or at www.sciencekit.com on the Internet. For alternate materials, see the activity on the listed page.

Study Guide, p. 63

http://www.sciencekit.com

Critical Thinking/Problem Solving

NAME DATE CLASS

Chapter 18

CRITICAL THINKING Bones, Muscles, and Skin

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.18

As you know, the skeleton protects the softtissues in your body. But the skeleton may notbe able to provide much protection from radi-ation. This is a concern for scientists at NASAwho are currently studying the effects of radi-ation on astronauts.

NASA wants to study the effects of radiationon the human body because of the potentialdanger to space shuttle astronauts and futurespace-station workers. In outer space, thereare cosmic rays that generally do not reachEarth’s surface. Cosmic rays are radiationgiven off by the sun and other stars. Scientistsknow that radiation can cause serious biologi-cal damage. It disrupts the normal chemicalprocesses of living cells, causing them to growabnormally or die.

Recently NASA sent a human skull, whichwas donated to science, into space. This spe-cial skull has been aboard several shuttleflights. The skull is filled with plastic contain-ing tiny meters and detectors that are able to measure different levels and kinds of radiation.

NASA wants to reproduce the effects ofspace travel on the human body as closely aspossible. NASA’s aim is to discover not onlythe amount of radiation that astronauts areexposed to while in space, but also the kindsof radiation. Radiation from iron particles, forexample, can be much more damaging thanradiation from other particles.

Through the use of this special skull, NASAhas also been able to compare the levels and kinds of radiation that occur in differentorbits. It is believed that the radiation in polar orbits has more energy than the radia-tion in orbits around the equator.

Although sending a human skull into spacemay seem eerie, astronauts may find comfortin knowing that it is accompanying them fortheir own good. NASA also plans to send ahuman torso into space. It will be used to testthe effects of charged particles on the body’ssoft tissues.

Applying Critical Thinking Skills1. Why would astronauts find comfort in having a human skull accompany them on their space

shuttle flight?

2. How can scientists justify making a human skull part of their experiments?

3. What are some of the possible solutions that may protect astronauts from being exposed to dangerous levels of cosmic radiation?

A Space Shuttle Ride for a Phantom Head

L2

Accessibility

Resource Manager

Spanish Resources

L2

Hands-on Activities

Lab ManualActivity Worksheets

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 97

NAME DATE CLASS

Chapter 18

ACTIVITY 18-1 Observing Bones

Lab Preview1. Other than movement, name three functions of bones. ________________________________

give shape and support to the body, produce blood cells, and store major quantities

of calcium and phosphorus.

2. Why is the sharp object safety symbol necessary? _____________________________________

punctures due to the use of a scalpel

To move, animals must overcome the force of gravity. A skeleton aidsin this movement. Land animals need skeletons that provide supportagainst gravity. A flying animal needs a skeleton that provides support yet also allows it to overcome the pull of gravity and fly.Bones are adapted to the functions they perform. Find out if there is a difference between the bones of a land animal and those of aflying animal.

A Traditional Experiment

What You’ll InvestigateWhat are the differences in the bone struc-

tures of land animals and flying animals?

Goals• Learn the parts of a bone.• Observe the differences between the

bones of land animals and those of flying animals.

Materials • beef bones (cut in half lengthwise)• chicken leg bones (cut in half lengthwise)• hand lens• paper towels

Procedure1. Copy the data table and use it to record

your observations.

2. Obtain a beef bone and a chicken leg bonethat have been cut in half along the lengthfrom your teacher.

3. Observe the bones with a hand lens.

4. Identify the periosteum, compact bone,spongy bone, and the remains of any mar-row that may be present.

5. Draw a diagram of the bones and labeltheir parts on the next page.

6. In the data table, write down any observa-tions that you make.

7. Try to bend the bones to determine theirflexibility.

Bones protect internal organs,

because of the danger of cuts or

L2Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 95

NAME DATE CLASS

Chapter 18

LABORATORY MANUALAnalyzing Bones 35

The skeletal system provides support for the body and protection for internal organs. In order toprovide these functions bones must be hard and strong. Scientists have discovered that theelement calcium is responsible for making bones strong. Adding calcium to a bone can make itstronger, while removing calcium will make the bone weak and brittle. The amount of calcium inbones can change over time. Certain types of hard physical exercise and work can result incalcium added to bones, while certain diseases and diets can result in calcium lost from bones.

StrategyYou will test the hardness of chicken bones before and after soaking them in different liquids.You will hypothesize which solutions will remove calcium from bones and test your hypothesis.

Materials chicken bones apron(boiled and cleaned) goggles4 beakers or jars gloveshydrogen peroxide forcepsa liquid (chosen by waterthe student) vinegar

Procedure

Data and ObservationsTable 1

Prepare chicken bones in advance. Bones fromcooked chicken can be boiled for 20–30 min to helploosen any pieces of tissue left on the bones. Cool thebones and use a knife to easily scrape off theloosened material. Allow the bones to dry before theexperiment. The softening effect of calcium loss canbest be observed with the smaller diameter leg bones.

Students may notice that the ends of the bones are softer. Becausechickens sold in stores are young birds, the ends of the bones have notcompletely calcified and still contain large amounts of cartilage.

1. Four liquids will be tested for their effects onbones. Three of the liquids are listed in Table1. You should choose a fourth liquid to test(lemon juice, fruit juices, soft drinks, milk, andso forth). Have your choice approved by yourteacher and then record the type of liquid inTable 1.

2. Make a hypothesis about the effects eachliquid will have on the strength of chickenbones. Write your hypothesis in Table 1.

3. Check the hardness of a chicken bone bygently twisting and bending the bone. Becareful not to crack or break the bone.

4. Fill each beaker with one of the liquids. Labelthe beakers with your name and the kind ofliquid.

5. Place a bone in each beaker of liquid. After 10min, observe the bones and record anychanges that you see in Table 2.

6. After 48–72 h, use forceps to remove the bonesfrom the liquids. Rinse the bones with waterand observe them carefully. Record yourobservations in Table 2.

7. Retest the bones for hardness by twisting andbending. Record the results of the test in theResults column of Table 1.

Liquid Hypothesis Results

water Answers will vary. No effect on bone strength

vinegar Answers will vary. Softens the bone

hydrogenperoxide

(student Answers will vary. Answers will vary.choice)

Answers will vary. No effect on bone strength

L2

Hands-on Activities

Chapter Review

Part A. Vocabulary ReviewSelect the term from the following list that matches each description.

cardiac muscle cartilage dermis epidermisimmovable joints involuntary muscles joint ligamentsmelanin muscle skeletal muscles skeletal systemsmooth muscles tendons

_____________________ 1. the basic framework of the body

_____________________ 2. thick, smooth layer of tissue that covers the ends of bones

_____________________ 3. any place where two or more bones meet

_____________________ 4. tough bands of tissue that hold bones together

_____________________ 5. the kind of joints of skull bones

_____________________ 6. organ that contracts and gets shorter

_____________________ 7. any muscles that you do not consciously control

_____________________ 8. voluntary muscles that are the most numerous in the body

_____________________ 9. thick bands that pull on bone as a muscle contracts

_____________________ 10. involuntary muscles in the digestive system

_____________________ 11. involuntary muscle found only in the heart

_____________________ 12. the surface layer of the skin

_____________________ 13. the layer of tissue under the epidermis

_____________________ 14. chemical that gives skin its color

Write the name of each bone part shown in the illustration below.

35

NAME DATE CLASS

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

Bones, Muscles, and Skin

Chapter 18

CHAPTER REVIEW

skeletal system

cartilage

joint

ligaments

immovable joints

muscle

involuntary muscles

skeletal muscles

tendons

smooth muscles

cardiac muscle

1/18:1

1/11:1

2/18:1

1/18:1

2/18:1

6/18:3

3/18:2

4/18:2

4/18:2

4/18:2

4/18:2

6/18:3

6/18:3

6/18:3

1/18:1

epidermis

dermis

melanin

spongy bone

marrow

periosteum

compact bone

cartilage

15.

16.

17.

18.

19.

L2

Performance Assessment

When your muscles, bones, and nerves grow, other parts of your body develop. The growth of yourmuscles, for example, must keep up with the growth of your bones. Facial features develop at thesame rate the skull grows. Organs, such as your kidneys, must develop at a rate that can keep themdoing their job in a larger body.

Much of this growth cannot be easily seen. You can’t tell by looking in the mirror how large yourheart, liver, or brain have become. The length of a muscle or nerve is not obvious. One part of thebody in which growth can easily be seen, however, is the skeletal system. For example, as your legbones grow longer, you become taller. Your arms, fingers, feet, and head all become larger or longer asyour bones in those areas grow. Because it forms the structure of the entire human body, the growth ofthe skeletal system is shown in the size, including the height, of the body.

A father kept a record of his daughter’s height from the time she was born until she was eight yearsold. The record is shown in the following table.

1. Construct a bar graph from this data.

2. Using the graph, find the two years between which the girl’s skeleton grew the most.

3. Between what two years did her skeleton grow the least?

4. From the data, can you infer a general pattern of skeletal growth during these years?

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.32

NAME DATE CLASS

Chapter 18

SKILL ASSESSMENT She’s Just a Growing Girl

Year

Birth

1

2

3

4

5

6

7

8

Height

42 cm

50 cm

86 cm

92 cm

104 cm

112 cm

118 cm

124 cm

128 cm

L2

Assessment Extending ContentExtending Content

Accessibility

Multicultural ConnectionsTest Practice WorkbookAssessment

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 81

I. Testing ConceptsMatch the description in the first column with the item in the second column by writing the correct letter in the spaceprovided. Some items in the second column may not be used.

_____ 1. tough outer covering of bones 1/18:1

_____ 2. tissue in center of bones that makes blood cells 1/18:1

_____ 3. any place where two or more bones meet 2/18:1

_____ 4. tough bands of tissue that hold bones together 1/18:1

_____ 5. any organ that contracts and gets shorter 6/18:3

_____ 6. thick bands of tissue that attach muscles to bones 7/18:3

_____ 7. any muscles that are not consciously controlled 7/18:3

_____ 8. involuntary muscles of the digestive system 7/18:3

_____ 9. the inner layer of skin 6/18:3

_____10. the surface layer of skin 6/18:3

For each of the following, write the letter of the term or phrase that best completes each sentence.

_____ 11. The human skeleton has _____ bones of various sizes and shapes. 1/18:1a. 106 b. 156 c. 206 d. 256

_____12. _____ make bone hard. 1/18:1a. Carbohydrates b. Minerals c. Proteins d. Fats

_____13. The hard, strong layer of bone is called _____ . 1/18:1a. bone marrow b. cartilage c. compact bone d. periosteum

_____14. One function of spongy bone is to _____ . 1/18:1a. produce red blood cells c. produce periosteumb. store minerals d. make the bone lightweight

_____15. The smooth, flexible layer of tissue covering the ends of bone is _____ . 1/18:1a. cartilage b. compact bone c. periosteum d. spongy bone

_____16. The joints of the bones of the skull and pelvis are classified as _____ joints. 2/18:1a. ball-and-socket b. gliding c. hinge d. immovable

_____17. _____ joints are the most frequently used joints in your body. 2/18:1a. Ball-and-socket b. Gliding c. Immovable d. Pivot

_____18. The outer ear and the end of the nose are made of _____ . 1/18:1a. cartilage b. osteoblasts c. osteoclasts d. spongy bone

_____19. About _____ of your body mass is muscle tissue. 5/18:2a. 20–25% b. 25–30% c. 30–35% d. 35–40%

NAME DATE CLASS

Chapter 18

CHAPTER TEST Bones, Muscles, and Skin

i

f

d

e

h

l

c

k

a

b

a. dermis

b. epidermis

c. involuntary muscles

d. joint

e. ligaments

f. marrow

g. melanin

h. muscle

i. periosteum

j. skeletal muscles

k. smooth muscles

l. tendons

m. voluntary muscles

c

b

c

d

a

b

b

a

d

L2 L2Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

35

In the humid air of the Amazon rain forest, athousand shades of green form a lush canopyoverhead. Vines coil up the trunks of gianttrees as scarlet birds fly from branch tobranch. A monkey howls and then is silent.The ways of the forest hunter are resourcefuland effective. Hunting game to eat and usingplants for food, shelter, and medicine are allpart of the forest technology that has beenknown to the indigenous (native) people ofthe South American rain forest for genera-tions. Knowledge of what is urihi ta rimo—“ofthe forest”—has kept people such as theYanomamo of northern Brazil in harmonywith the vast ecosystem in which they live.

But as progress and development invade therainforest, indigenous people struggle tomove forward without losing their culturalidentity and health. Certain aspects of rain-forest life have become known to peoplethroughout the world. The treasure trove ofmedicinal plants once restricted to the rainforest can be used by everyone. One exampleis curare, the toxic substance used by theYanomamo to make poison arrows for hunt-ing. This powerful drug is used for medicinalpurposes by physicians all over the worldbecause of its effectiveness as a muscle relax-ant during surgery.

Rain Forest TechnologyThe natural resources of the South American

rain forest are extraordinary. Plants providebuilding materials for houses, abundant food,as well as a wealth of bark, seeds, leaves, androots with a variety of properties. Many areused for healing. Some plants are used fortheir strong toxins. Two groups of trees andshrubs, the genus Chondodendron and thegenus Sttrychnos, provide the compounds that yield the poison curare. The name curarecomes from the word woorari, meaning poison.

Traditionally, the people in a Yanomamo vil-lage would be able to produce all their every-day items from the resources available in therain forest. To go out hunting for game to eatmeant making a bow and arrow from localmaterials. They make their bows from dense,hard palm wood. The bow is strung with longtwisted cords of inner tree bark. Then splin-ters of palm wood are used to make huso namo

points, the curare-poisoned tips of arrows.These arrows are about a foot long. They areweakened in several places by cutting thempart of the way through. The Yanomamo usu-ally make the arrow points in a bundle of 30or 40 at once. They make the poison by firstsoaking the vine of the plant in hot water.Then other plant ingredients are added tomake the mixture stick to the arrows. Whatresults is a dark brown resin that has an aro-matic odor. Traditionally, it is prepared in anearthenware pot or gourd. Then the dark mix-ture is painted onto the sharp arrow points.Longer lance-like points are used to kill largergame such as the tapir (a large hoofed animal,similar to the pig). Small bone barbs are usedfor hunting birds. Yanomamo boys becomeskilled hunters at about age ten. Being able tohunt is an important skill necessary for thewell being of the community.

How Curare WorksIf a hunter hits the target animal, such as a

monkey, the arrow breaks along its weakenedshaft. The monkey is unable to pull out thearrow point, and the curare enters its blood-

Chapter 18

MULTICULTURAL CONNECTIONS Curing with Curare

NAME DATE CLASS

L2

438D

Meeting Different Ability Levels

Transparencies

Chapter 16 Chapter 16 Bones, Muscles, and Skin

Enrichment WorksheetsReinforcementStudy Guide

for Content Mastery

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Name Date

CHAPTER 18 Study Guide for Content Mastery

Overview Bones, Muscles, and SkinDirections: In the space below each illustration, write the type of joint and give an

example.

type:

example: elbow, knee, finger

hinge type:

example: ankle

vertebrae, wrist,

gliding type:

example: arm

pivot

type:

example: skull, pelvis

immovable type:

example: hip, shoulder

ball and socket

BASICCopyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 49

NAME DATE CLASS

Chapter 18

REINFORCEMENT The Skeletal System

Use with Section 1

Listed below are the four kinds of movable joints. Label the illustrations.

1. ____________________ 2. ____________________

3. ____________________ 4. _____________________

Describe each type of joint.

5. pivot joint: _________________________________________________________________________

6. ball-and-socket joint: ________________________________________________________________

another bone

7. hinge joint: _________________________________________________________________________

8. gliding joint:________________________________________________________________________

List the five major functions of the skeletal system.

9. ___________________________________________________________________________________

10. ___________________________________________________________________________________

11. ___________________________________________________________________________________

12. ___________________________________________________________________________________

13. ___________________________________________________________________________________

one bone rotates in the ring of another bone

one bone has a rounded end that fits into a cup-like cavity on

back and forth movement like the hinges on a door

one part of a bone glides over another bone

It gives shape and support to the body.

It protects the body’s internal organs.

It provides a place for major muscles to attach.

In the marrow of some bones, blood cells are formed.

It provides a place for the minerals calcium and phosphorus compounds to be stored.

hinge joint

gliding joint

pivot joint

ball-and-socket joint

AT LEVELCopyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 49

The Skeletal System

Use with Section 1

NAME DATE CLASS

Chapter 18

ENRICHMENT

Bones of Animals Sometimes we forget that human beings are animals and that our structures are very similar to

those of other animals. A doctor and a veterinarian even use the same names for the bones of ahuman and a dog, as well as for the bones of many other animals.

Below are diagrams of two skeletons—one of a dog and one of a human being. The diagram of adog is labeled with the names of the bones. These same names are used for human bones. Thebones of a human may be in a slightly different position or have a slightly different shape.

Study the diagram of the dog. Then label the corresponding bones on the human. All the bone names can be trans-ferred to the human skeleton.

skull

scapula

humerus

femur

tibia

fibula

ankle bones

mandible

radius

wrist bone

ulna

ribs

vertebrae

pelvis

skull

scapula

humerus

femur

tibia

fibula

ankle bones

mandible

radius

wrist bones

ulna

ribs

vertebrae

pelvis

CHALLENGE

Meeting Different Ability Levels

Section Focus Transparencies

Teaching TransparenciesScience Integration

Transparencies

Copyright©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 45

45

PUTTING IT TOGETHERIf you removed the seats, doors, and body panels of a car, you’d find that

these parts are all connected to and supported by a metal framework calledthe chassis. The chassis of a car includes the wheels, frames, and mechanicalparts on which the body of the car is supported.

1. What are some functions of the chassis of a car?

2. How do you think the role of a car’s chassis is similar to the role of yourskeleton?

3. In your body, the places where two bones meet are called joints. Whatparts of the car’s chassis are similar to joints?

SECTION FOCUS TRANSPARENCYSection 16-1

L2Copyright©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 46

46

ROBOTICSMany science fiction films portray robots as companions to the characters

in the movies. However, robots are now commonly used in industry to per-form jobs that were once done by people. Unlike the robots frequentlyshown in movies, these industrial robots do not look anything like people oranimals and they usually do not carry on friendly conversation.

1. What types of jobs might a robotic arm be suited to?

2. What are the advantages and disadvantages of using robotic arms insteadof people to do a job?

3. How is the way the robotic arm works and moves similar to the way ahuman arm works and moves?


Grab

Case

Arm

Floodlight

Closed-circuittelevision camera

Tracks for movingover rough ground

L2Copyright©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 47

47

PEEL IT OFF!Many of the fruits and vegetables we eat as food are enclosed in an outer

covering. We remove these coverings from the food before we eat it. Forexample, oranges, tangerines, and grapefruits are enclosed by rinds. Mostnuts are enclosed in shells. Other fruits and vegetables, such as bananas andpotatoes, are covered with peels.

1. What role do the coverings of fruits and vegetables provide to the plants?

2. What organ of the human body plays a role similar to the peel of a bananaor the rind of an orange?


L2

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

16SCIENCE INTEGRATION TRANSPARENCY

The Body’s Lever Systems

Lever Type

Body Equivalent

First Class LeverA first-class lever hasthe fulcrum betweenthe load and the effortforce.

In your body, the skullpivots on the top ver-tebra as neck musclesraise your head upand down.

Second Class LeverA second-class leverhas the load betweenthe fulcrum and theeffort force.

Raising the body up onyour toes occurs whenthe leg muscles pull onthe leg and foot.

Third Class LeverA third-class lever hasthe effort forcebetween the fulcrumand the load.

Your arm works like alever when you pick upan object with yourhand. The contractingbiceps muscle is theforce that moves thebones of your forearmat the elbow.

Types of Levers in the Human Body

L2Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

31. HUMAN SKELETAL SYSTEM

Cranium

Mandible

Scapula

Humerus

Ulna

Radius

Carpals

Metacarpals

Phalanges

Tibia

Fibula

Tarsals

MetatarsalsPhalanges

Patella

Femur

Sacrum

Pelvic bone

Vertebrae

Ribs

Sternum

Clavicle

Maxilla

L2Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

32. HUMAN MUSCLE SYSTEM

Vastus Lateralis

External Abdominal Oblique

L2

Transparencies

This is a representation of key blackline masters available in the Teacher Classroom Resources.See Resource Manager boxes within the chapter for additional information.

L1 L2 L3

438C CHAPTER 16 BONES, MUSCLES, AND SKIN

sebaceous glands se-crete a substance com-posed of fats, salts,proteins, and water.The oil serves to lubri-cate the skin and keepit flexible. It alsohelps reduce evapora-tion of water from theskin’s surface.

The hair follicles produce masses of epider-mal cells. As they are pushed up through thefollicle, they synthesize the protein keratin,giving the hair structure a certain hardness.The cells become flattened and die. Theamount of melanin gives color to the hair. Hav-ing no pigment results in a hollow hair shaftand gives it a white appearance.

Hair (Section 16-3)

Hair is made up of threads of cells that developfrom the epidermis. Because hair comes fromthe skin, it is considered to be an appendage ofthe skin. Scalp hair provides insulation againstcold air and the heat of the sun. It also protectsagainst bumps. Eyebrows help cushion theeyes, reduce glare, and prevent sweat from run-ning into the eyes. Eyelashes screen dirt andother particles from entering the eye. Hairsfound in other body openings, including nos-trils and ears, trap dust particles and preventthem from entering the body.

Skin (Section 16-3)

The skin that covers our body is a highly versa-tile organ. It is stretchable, tough, and selectivelypermeable. The uppermost layer, the epidermis,is only about 30 to 60 cells in thickness. Underthe epidermis is the dermis layer that varies from1 to 3 mm in thickness. The entire surface area ofthe skin is nearly 1.2 m2.

The outermost layer of the epidermis is com-posed of thin, flat, nonliving cells that are beingshed constantly. New epidermal cells are con-stantly being formed in the innermost layers toreplace the shed cells. It takes about 14 days for acell to travel from the base of the epidermis to thesurface. Cells known as melanocytes produce thepigment melanin. The number, size, and distrib-ution of melanin cells determine the skin color.

The dermis has two layers. The upper papil-lary layer is composed of connective tissue andhas many small blood vessels and nerves. Thefolding of this layer produces the ridges on theskin’s surface. Most noticeable are the patternsof ridges that produce our fingerprints. Thelower reticular layer is composed of dense con-nective tissue with many collagen fibers. Thislayer also contains the sweat glands, oilglands, and hair follicles.

Sweat glands can be found in great num-bers on the hands, feet, chest, and neck. Theyare most numerous on the palms of the handswhere they average 350/cm2. Perspiration issimilar to a weak solution of urine. The oil or

438F

For current events or science in the news,access the Glencoe Science Web Site atwww.glencoe.com/sec/science/ca

ontent Background

ontent Background

CC

Teacher to TeacherTeacher to Teacher“To help students remember the bones of the human skeletal

system, I have them touch the area of their body where the bone

is located and identify each bone by its common and its scientific

name. They are tested orally in this way as well.”

Petrolia Moss, Teacher

North Heights Junior High

Texarkana, AR

Chapter 16

438E CHAPTER 16 BONES, MUSCLES, AND SKIN

The Skeletal System (Section 16-1)Human bodies have endoskeletons, which meansthat the skeleton is located inside the body. Thereare approximately 200 bones making up the skele-ton. The number of exact bones varies becausesome bones fuse at different periods of time.

The skeleton is divided into the appendicularskeleton and the axial skeleton. The appendicu-lar skeleton is made up of the bones of arms andlegs and the girdler that attaches these bones tothe rest of the body. The axial skeleton is madeup of the skull, backbone, ribs, and breastbones.

Bones (Section Section 16-1)

Bone consists of numerous microscopic unitscalled Haversian systems. The centers of theseunits have canals. Blood and lymph vessels andnerves run through these canals. Surroundingthe canals are concentric layers of minerals andother inorganic materials. These layers, calledlamellae, are connected to each other and thecanal by minute channels. Blood and nutrientsdiffuse through the channels and canals toreach all the bone components. Within the lay-ers are small cavities in which are found thebone cells, the osteocystes.

The Muscular System (Section 16-2)

Muscles can provide for motion of body partssuch as the churning of the stomach, beating ofthe heart, and moving an arm. They also cancause the entire body to move from one place to

another. This is termed locomotion. Motion andlocomotion are the result of muscle contraction.Muscle cells are elongated, threadlike cells thatchange shape by becoming shorter and thicker.

The contraction of a muscle cell involves acomplex set of chemical reactions. The stimulusfor these chemical reactions is called acetyl-choline, which is released by the ends of themotor neurons. This action sends an impulseover the surface and into the interior of the mus-cle fiber. Calcium ions are released, which re-sults in muscle contraction. The energy requiredfor the contraction is supplied by molecules ofadenosine triphosphate (ATP). The ATP causesan interaction between the two muscle proteins.

A simple contraction has three phases. (1) Thelatent period is the length of time between thestimulus and the response. (2) The contractionperiod is the time of the actual contraction of themuscle. (3) The relaxation period is the time ofthe muscle relaxation.

Products Available from GlencoeTo order the following products for use with this chap-ter, call Glencoe at 1-800-334-7344:

CD-ROMNGS PictureShow: Human Body 1Curriculum KitGeoKit: Human Body 2Transparency SetNGS PicturePack: Human Body 1VideodiscSTV: Human Body

Products Available from NationalGeographic SocietyTo order the following products for use with this chapter,call National Geographic Society at 1-800-368-2728:

VideosIncredible Human MachineMuscular and Skeletal Systems

Teacher’s Corner

Chapter 16 Bones, Muscles, and Skin

CD-ROMGlencoe Science Voyages Interactive CD-ROM

Chapter SummariesUse the Chapter Summary to introduce, teach,or review chapter material.

Helping You Prepare


Observe Muscle Size

1. Hang your straightened arm toyour side in a relaxed position.Use a measuring tape to deter-mine the size (circumference) of your upper arm when it isrelaxed.

2. Flex your arm by bending it andmaking a fist. Measure yourupper arm again.

3. How did the size of your upperarm change when you flexedyour arm?

4. What happened to the muscle to cause this change? Did themuscle become larger? Or, did it shorten and bunch up?

Explore Activity

Like this athlete on the left, you might have experienced tiredmuscles after completing some strenuous physical activity.

You round the bend one last time at the school track, proud tohave finished an unusually long run in good time. Your musclesfeel as though they couldn’t carry you another meter. You have improved your time, and you know your muscles areclenched. Try the following activity to measure muscles in different states.

Write a paragraphabout what you think is happening to themuscles as youstraighten and flex your arm.

439

439

Explore ActivityPurpose

Kinesthetic Use theExplore Activity to in-

troduce students to muscles.Inform students that theywill learn more about themuscular and skeletal sys-tems as they read the chap-ter.

PreparationHaving several measuring

tapes will lessen the lengthof the activity period andkeep students on task.

Materialsmeasuring tapes

Teaching StrategiesHave students work in

pairs so they can measureone another’s muscles in arelaxed and a flexed state.

The upperarm thick-ens when

the muscle is flexed becausethe muscle contracts, orshortens. When the muscleshortens, its mass is com-pressed and the muscle be-comes thicker.

Process Ask students to ob-serve and decide where thelargest muscles in their bod-ies are located. The largestmuscles are located where theycan move the limbs and otherlarge parts of the body, such asthe back. Use PerformanceAssessment in the ScienceClassroom, p. 17.

COOP LEARNELLL2

Assessment

PortfolioRefer to p. 459 for suggested items that stu-dents might select for their portfolios.Performance AssessmentSee p. 459 for additional Performance As-sessment options.Skill Builder, pp. 452, 457MiniLab, pp. 451, 456Activity 16-1, p. 446; 16-2, p. 453

Content AssessmentSection Assessment, pp. 445, 452, 457Chapter Assessment, pp. 460–461Proficiency Prep, pp. 445, 452

Assessment Planner

CHAPTER 16Bones, Muscles,

and SkinBones, Muscles,

and Skin

Chapter Preview

Section 16-1The SkeletalSystem

Section 16-2The MuscularSystem

Section 16-3Skin

Skills Preview

Skill Builders• Outline

• Map Concepts

Activities • Observe and Collect

Data

MiniLabs • Observe and Experiment

Bones, Muscles,and Skin

✔Reading Check

16

Before reading this chapter,

find out what these prefixes

mean: osteo-, peri-, im-, and

epi-. Identify and define sev-

eral words that begin with

each of these prefixes.

C H A P T E R

438

Bones, Muscles,and Skin

438 CHAPTER 16 BONES, MUSCLES, AND SKIN

CHAPTER OVERVIEWSection 16-1 This sectiondiscusses the five major func-tions of the skeletal system.Details of the characteristics,composition, and develop-ment of bone and bone jointsare also discussed.Section 16-2 The majorfunctions and types of mus-cles are discussed. An expla-nation of how muscle actionproduces movement is given.Section 16-3 This sectiondiscusses the tissue layers,structures, and five majorfunctions of the skin.

Chapter Vocabularyskeletal involuntary system muscle

marrow skeletal periosteum musclecartilage tendonjoint smooth ligament muscleimmovable cardiac joint muscle

movable epidermisjoint melanin

muscle dermisvoluntarymuscle

Theme ConnectionEnergy One of the themes inthis chapter is Energy. Whenthe skeletal and muscularsystems work to producemovement, energy is usedand work is done. Food isprocessed by the digestivesystem and converted intoglucose. The chemical energyin glucose is used by musclesand transformed into me-chanical energy.

MultipleLearning

Styles

Look for the following logos for strategies that emphasize different learning modalities.

Linguistic Using Science Words, p. 441; Across the Curriculum, p. 443;

Reteach, p. 457; Preview, p. 458Visual-Spatial Quick Demo, p. 441;Making a Model, p. 443; Assessment,

p. 446; Reteach, pp. 450, 458; Activity, p. 453; MiniLab, p. 456

Auditory-Musical Out of Time, p. 458

Kinesthetic Explore Activity, p. 439;Activity, pp. 442, 446; Reteach,

p. 448; Multiple Learning Styles, p. 450;MiniLab, p. 451; Quick Demo, p. 456; Assessment, p. 457

Interpersonal Review, p. 458

Looking at BoneAs you study bones, you’ll notice

several characteristics. The differences in sizes and shapes are probably mostobvious. Bones are frequently classifiedaccording to shape. Bone shapes, shownin Figure 16-2, are genetically controlledand also are modified by the work ofmuscles that are attached to them.

Bone StructureUpon close examination, you’ll find

that a bone isn’t all smooth. Bones havebumps, edges, round ends, rough spots,and many pits and holes. Muscles andligaments attach to some of the bumpsand pits. Blood vessels and nerves enterand leave through the holes. Many inter-nal and external characteristics of boneare seen in the picture of the humerus shown in Figure 16-3.

As you can see in Figure 16-3, the surface of the bone is covered with a tough, tight-fitting membrane called theperiosteum (per ee AHS tee um). Small blood vessels in theperiosteum carry nutrients into the bone. Cells involved inthe growth and repair of bone also are found here. Under theperiosteum is compact bone, which is a hard, strong layer ofbone. Compact bone contains bone cells, blood vessels, and a

Periosteum

Humerus

Compactbone

Blood vesselssupplying

living bone

Spongybone

Spongybone

Marrowcavity

Cartilage

Compactbone

Periosteum

Haversiansystem

Blood vesselsand nerves incenter

16 1 THE SKELETAL SYSTEM 441

Figure 16-2 The shapeof a bone provides cluesabout what function it per-forms within the body. Wherein the body would you findthe bones shown above?

Figure 16-3 Bone ismade of layers of living tis-sue. Compact bone isarranged in circular struc-tures called Haversian sys-tems. What is the tough,tight-fitting membrane thatcovers the surfaces ofbones called?

Femur

Phalanges

Calcaneus

Scapula

Vertebra

16-1 THE SKELETAL SYSTEM 441

2 TeachQuick Demo

Visual-Spatial Use 4 � 6cards and tape to make

one rectangular column andone cylindrical tube. Standthe structures on a flat surfaceand balance textbooks on thetop of them. Note whichstructure collapses first. Re-late this strength to the long,round bones of our body.

Caption AnswersFigure 16-2 femur—leg,scapula—shoulder, phalangesand calcaneus—feet, vertebra—backboneFigure 16-3 periosteum

CD-ROMGlencoe Science VoyagesInteractive CD-ROMExplorationsHave students do the interactiveexploration What are the majorbones of the human body?

Figure 16-1 Each illustration shows aframework. Have students explain howeach framework is suited to support thestructure of which it is a part. The sky-scraper is rigid and fixed to Earth; it has lit-tle flexibility. The individual bones of theskeleton are rigid, but the whole skeleton isflexible and allows movement of the body.

LearningVISUAL

Using Science WordsLinguistic Have stu-dents find nonscientific

meanings of the use of theword skeleton. Refer to such id-ioms as a skeleton outline, skele-ton force, and skeleton structure.L2

Osteoporosis is a condition inwhich the bones become porous and thindue to reduced bone mass. Factors that in-crease the risk of this condition includebeing a female, being Caucasian, chroniclow calcium intake, lack of exercise, beingunderweight, and smoking.

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Page 440: 5a, 5b, 5cPage 441: 5a, 5b, 5c

CA Science ContentStandards

The Skeletal SystemA Living Framework

The skull and crossbones flag flying on a pirate ship haslong been a symbol of death. You might think that bones aredead structures made of rocklike material. It’s true that askeleton’s bones are no longer living, but the bones in yourbody are very much alive. Each bone is a living organ madeof several different tissues. Cells in these bones take in nutri-ents and expend energy. They have the same requirements asyour other cells.

Major Functions of Your Skeletal SystemAll the bones in your body make up your skeletal system,

which is the framework of your body. The human skeletalsystem has five major functions. First, it gives shape and sup-port to your body, like the framework of the building in Figure 16-1. Second, bones protect your internal organs: ribssurround the heart and lungs, and a skull encloses the brain.Third, major muscles are attached to bone. Muscles movebones. Fourth, blood cells are formed in the red marrow ofsome bones. Bone marrow is a soft tissue in the center of

many bones. Finally, the skeleton iswhere major quantities of calcium

and phosphorous compounds arestored for later use. Calcium andphosphorus make bone hard.

16 1

The five major functions ofthe skeletal systemHow to compare and contrastmovable and immovablejoints

Vocabularyskeletal systemmarrowperiosteumcartilagejointligamentimmovable jointmovable joint

You’ll gain an understandingof the motion of each of yourbody parts and what allowsyou to move these body parts.

Why What You'll Learn

It's Important

You'll Learn

It's Important It's Important


It's Important

You'll Learn

It's Important

You'll Learn

Figure 16-1 The 206 bonesof a mature adult support thebody just as the steel girderssupport a skyscraper.

440 CHAPTER 16 BONES MUSCLES AND SKIN


Prepare

PreplanningRefer to the Chapter Orga-nizer on pp. 438A–B.

1 Motivate


Recall the role of the skele-tal system in classifying ver-tebrate animals. Remind stu-dents of the function of theskeletal system in providingsupport and framework forthe vertebrate body.

SECTION 16•1

Bellringer

Before presenting the lesson,display Section Focus Transparency 45 on the

overhead projector. Use the accompanying Focus Activityworksheet. ELLL2

Copyright©Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

45

45

PUTTING IT TOGETHER

If you removed the seats, doors, and body panels of a car, you’d find that

these parts are all connected to and supported by a metal framework called

the chassis. The chassis of a car includes the wheels, frames, and mechanical

parts on which the body of the car is supported.

1. What are some functions of the chassis of a car?

2. How do you think the role of a car’s chassis is similar to the role of your

skeleton?

3. In your body, the places where two bones meet are called joints. What

parts of the car’s chassis are similar to joints?

SECTION FOCUS TRANSPARENCY

Section 16-1

Refer to TheSkeletal System andBones on p. 438E.

ontent Background

ontent Background

CC

The following Teacher Classroom Resources can be used with Section 16-1:

Reproducible Masters

Activity Worksheets, pp. 85–86

Enrichment, p. 45

Laboratory Manual, pp. 89–90

Reinforcement, p. 45

Study Guide, pp. 61-62

Transparencies

Teaching Transparency 31 L2

ELLL1

L2

L2

L3

L2

Resource Manager

Shape Affects Strength

When designing a building, architects know that cer-tain shapes provide more support. Look closely at theshapes of the Haversian systems found in the crosssection of a bone. Does this system’s design add tothe overall strength of a bone? To find out, build twodifferent support structures and see which is stronger.

Solve the Problem

1. Determine what geometric design is formed byHaversian systems.

2. Use two flat disks of modeling clay, plastic drinkingstraws, and two wooden boards to build the twodifferent support structures.

3. Insert the straws, in random order, in one claydisk. Lay a board on top. Put pressure on theboard until the structure collapses.

4. Repeat step 3, but arrange the straws in the samedesign as the Haversian systems.

Think Critically

1. Which structure withstood more pressure? Howdoes this relate to the strength of your bones?

2. What geometric shape provides strength for yourbones?

3. Compact bone is made of a series of Haversiansystems. What impact do several of these struc-tures have on the strength of the whole bone?

4. Suppose paper were wrapped around the strawsin the second structure. What impact would thishave on the strength of the structure? What part ofan actual bone does the paper represent?


When osteoclasts break down bone, they release calcium andphosphorus into the bloodstream. This process keeps the cal-cium and phosphorus in your blood at about the same levels.

Where Bones MeetThink of the different actions you performed this morning.

You opened your mouth to yawn, chewed your breakfast,reached for a toothbrush, and stretched out your arm to turnthe doorknob as you walked out the door. All these motionswere possible because your skeleton has joints.

Any place where two or more bones meet is a joint. A jointkeeps the bones far enough apart that they do not rub againsteach other as they move. At the same time, a joint holds thebones in place. A ligament is a tough band of tissue thatholds bones together at joints. Many joints, such as yourknee, are held together by more than one ligament.

Visit the GlencoeScience Web Site atwww.glencoe.com/sec/science/ca formore information aboutbone development.


Making a ModelVisual-Spatial Use twocardboard paper towel

tubes and rubber bands tomodel how ligaments holdbones together at a joint.

Teacher FYIDuring arthroscopic sur-

gery, an arthroscope is in-serted through an incisionand the surgeon looks aroundinside the joint. Repair of thejoint is done through the inci-sion by means of special in-struments designed to beused with the arthroscope.

L1

Language Arts Have students look up periosteum and osteoblast in the dictionary.Have volunteers explain how the root of theword reflects its meaning.

Discussion Have students find out aboutbone fractures and discuss how they heal. Afracture is a break in a bone. The periosteuminitiates healing by forming new bone cells.These cells form a thick band of new bonearound the break. Over time, the thickenedband is reshaped by osteoclasts. L2

L3

Across the CurriculumAcross the CurriculumFor Internet tips, see Glencoe’s

Using the Internet in the Science Classroom.

Internet Addresses

Have students recall thatcylinders are stable structuresand are often used as support-ing columns in buildings.

Think Critically1. The cylinder; long bones

can withstand a great dealof compression.

2. cylinder3. These interconnected

cylinder-shaped units forma stronger structure.

4. The structure would become even stronger;the periosteum.

Page 442: 5a, 5b, 5cPage 443: 5a, 5b, 5c, 7b



ActivityKinesthetic Place achicken bone in a jar of

vinegar for several days. Re-move the bone and examineit. Have students note howthe mineral salts have dis-solved, leaving only elastictissue. Have them comparehow the bone originally feltwith how it feels now.

Correcting Misconceptions

Students often believe thatthe cartilage of a fetus ischanged into bone. Have stu-dents note that the cartilagebreaks down and is replacedby bone.

Answer to

Reading Check ✔

Bone has a hard, compact

outer layer composed mostly

of minerals and a porous inner

part.


protein base or scaffolding with deposits of calcium andphosphorus. The flexible protein base keeps bone from beingtoo rigid and brittle or easily broken.

Spongy bone is found toward the ends of long bones likethe humerus, as seen in Figure 16-3. Spongy bone is muchless compact and has many small, open spaces that makebone lightweight. If all your bones were completely solid,you’d have a much greater mass. Long bones have largeopenings, or cavities. The cavities in the center of long bonesand the spaces in spongy bone are filled with marrow.Marrow produces red blood cells at an incredible rate of morethan 2 million cells per second. White blood cells also are pro-duced in bone marrow, but in lesser amounts.

CartilageNotice in Figure 16-3 that the ends of the bone are covered

with a thick, slippery, smooth layer of tissue called cartilage.Cartilage does not contain blood vessels or minerals. It isflexible and is important at joints, where it absorbs shockand makes movement easier by reducing friction. In someathletes and in older people, cartilage sometimes wearsaway, resulting in a condition called arthritis. People witharthritis feel pain when they move.

Bone DevelopmentMonths before you were born,

your skeleton was first made ofcartilage. Gradually, the cartilagewas broken down and replaced bybone-forming cells called osteo-blasts (AHS tee oh blasts). Thesecells deposit calcium and phos-phorus that make bone tissuehard. At birth, your skeleton wasmade up of more than 300 bones.As you developed, some bonesfused, or grew together, so thatnow you have only 206 bones.

Healthy bone tissue is dynamic.Figure 16-4 shows that it is alwaysbeing formed and re-formed. Osteo-blasts are bone cells that build upbone. A second type of bone cell,called an osteoclast, breaks downbone tissue in other areas. This is anormal process in a healthy person.

✔

✔Reading Check

What are some charac-

teristics of bone?

Figure 16-4 Bone formationstarts with cartilage. Starting in themiddle of the bone, the cartilage isreplaced by hard bone. The solidtissue grows outward until theentire bone has hardened. Whattype of bone cell builds up bone?

Caption AnswerFigure 16-4 osteoblasts

VideodiscGlencoe Science VoyagesInteractive Videodisc—LifeSide 2, Lesson 8 Medical Diag-nostics: Tools of the Trade

!:D3DR^Ü"33316The Infinite Voyage: Miracles by DesignChapter 3 Artificial Body Partsand Durability: The ZinaBethune Story 8:00Refer to the Teacher Guide forbar codes and teaching strategies.

Geology Compact bone is composed ofthe crystalline mineral hydroxyapatite,C10(PO4)6(OH)2 and is interlaced with fibersof the protein collagen. Various salts of cal-cium, sodium, potassium, and magnesium arefound in between the crystals of hydroxy-apatite and serve to bind them together.

Integrating the SciencesIntegrating the Sciences



wrists and ankles and between vertebrae. Glidingjoints are the most frequently used joints in yourbody. You can’t write a word, pick up a sock, or takea step without using a gliding joint.

Making a Smooth MoveThink about what happens when you rub two

pieces of chalk together. Their surfaces begin to wearaway. Without protection, your bones also wearaway at the joints. Recall that cartilage is found at theends of bones. Cartilage helps make joint movementseasier. It reduces friction and allows the bones toslide over each other more easily. The joint also islubricated by a fluid that comes from nearby capil-laries. Pads of cartilage called disks are foundbetween the vertebrae. Here, cartilage acts as a cushion and prevents injury to your spinal cord.Figure 16-6 shows how a damaged hip joint can bereplaced.

Your skeleton is a living framework in the form ofbones. Bones not only support the body but also sup-ply it with minerals and blood cells. Joints are places betweenbones that enable the framework to be flexible and to be morethan just a storehouse for minerals.

1. What are the five major functions of a skeleton?2. Name and give an example of a movable joint

and an immovable joint.3. What are the functions of cartilage?4. Think Critically: A thick band of bone

forms around a healing broken bone. In time, the thickened band disappears. Explain how this extra bone can disappear.

5. Skill BuilderInterpreting Scientific

Illustrations You can learn a lot aboutbones when you see their internal structure. Dothe Chapter 16 Skill Activity on page 721 tointerpret sectional views of bones.

Section AssessmentSection Assessment

Database Use different references to find the names and shapes of themajor bones in the humanbody. Classify the bones as long, short, flat, and irregular. Use your computerto make a database. Then,graph the different classifica-tions of bones. If you needhelp, refer to page 697.

Figure 16-6 Some jointsdamaged by arthritis can bereplaced with artificial joints.How would this kind of surgeryhelp a person stay active?


4 CloseProficiency PrepUse this quiz to check stu-dents’ recall of section content.

1. Give an example of howthe skeleton protects or-gans. Ribs surround theheart and lungs; the skullencloses the brain.

2. What are the four shapesof your bones? long, short,flat, and irregular

3. Why is cartilage impor-tant at joints? It absorbsshock and makes movementeasier.

4. How does a hinge jointwork? It has a back-and-forth movement like thehinge on a door.

1. gives shape and support;protects internal organs;provides place for muscleattachment; producesblood cells; stores minerals

2. movable joint: base ofskull, shoulder, hip,elbow, knee, finger, wrist,and ankle; immovablejoint: skull and pelvis

3. provides padding; alsoprovides shape for earsand nose

4. Think Critically Osteo-clasts break down theextra bone material.


AssessmentOral Have students infer the function of afluid-filled cavity between two cartilagesurfaces. Use Performance Assessment inthe Science Classroom, p. 17.

Graph would indicate thatthere are more small, irregular,and flat bones than longbones.

Page 444: 5a, 5b, 5c, 6hPage 445: 5a, 5b, 5c, 6h,7b


Types of JointsJoints are classified as immovable or movable. Refer to

Figure 16-5 as you learn about different types of joints. Animmovable joint allows little or no movement. The joints ofthe bones in your skull and pelvis are classified as immov-able. A movable joint allows the body to make a wide rangeof movements. Gymnastics and working the controls of avideo game require movable joints. There are several types ofmovable joints: pivot, ball-and-socket, hinge, and gliding. Ina pivot joint, one bone rotates in a ring of another stationarybone. Turning your head is an example of a pivot movement.In a ball-and-socket joint, one bone has a rounded end thatfits into a cuplike cavity on another bone. This provides awider range of movement. Thus, your hips and shoulders canswing in almost any direction.

A third type of joint is a hinge joint. This joint has aback-and-forth movement like hinges on a door. Elbows,knees, and fingers have hinge joints. While hinge jointsare less flexible than the ball-and-socket, they are morestable. They are not as easily dislocated, or put out ofjoint, as a ball-and-socket joint. A fourth type of joint is agliding joint, where one part of a bone slides over

another bone. Gliding joints move in a back-and-forth motion and are found in your

Pivot joint

Vertebrae

Knee

Shoulder

Arm

Gliding joint

Ball-and-socketjoint

Hinge joint


Figure 16-5 When a soccerplayer kicks a ball, several typesof joints are in action. Which typeof joint permits the widest rangeof movement?

Skull


Kinesthetic Rub two pieces ofchalk together to show how fric-

tion would quickly wear away theends of bones if they were not pro-tected by cartilage.

Multiple Learning StylesHealth Have an athletic trainer, sportsmedicine physician, or sports physical thera-pist come to the class to discuss athletic injuries common to adolescents and adults.

Across the CurriculumAcross the Curriculum

Use the Flex Your Brain activity to have students explore BONE.

Flex Your BrainFlex Your Brain

Caption AnswersFigure 16-5 the ball-and-socket jointFigure 16-6 The new jointwould allow the person to movethe joint without feeling pain.

Using an AnalogyMoving parts of machines

require protection from fric-tion. Lubricants such as oiland grease and special coat-ings serve to reduce the wearof the parts. Moving parts ofthe body at bone joints havespaces between the bones.These spaces have lubricatingfluids called synovial fluidsand special sacs of fluids, thebursae and synovial sheaths,to reduce friction betweensurfaces.

3 AssessCheck for Understanding

ActivityWrite the vocabulary for

this section on the board.Have the students discuss thefunction of each. Have themdraw a bone and label itscomponents.

ReteachKinesthetic Bring in theleg and wing bones of

cooked chicken to examinethe ends of the bones for car-tilage.

ExtensionFor students who have

mastered this section, use theReinforcement and Enrich-ment masters.

L1

The MuscularSystemMoving the Human Body

A driver uses a road map to find out what highway con-nects two cities within a state. You can use the picture inFigure 16-7 to find out which muscles connect some of thebones in your body. A muscle is an organ that can relax andcontract to allow movement. This contraction, or pull,within the muscle provides the force to move your bodyparts. In the process, energy is used and work is done.Imagine how much energy is used by the more than 600muscles in your body each day. No matter how still youmight try to be, some muscles are always moving in yourbody. ✔

16 2 THE MUSCULAR SYSTEM 447

16 2

The major function of musclesHow to compare and contrastthree types of musclesHow muscle action results inmovement of body parts

Vocabularymusclevoluntary muscleinvoluntary muscleskeletal muscletendonsmooth musclecardiac muscle

The muscular system isresponsible for how youmove and the production of heat in your body. Musclesalso give your body its shape.


It's Important

You'll Learn



It's Important

You'll Learn

It's Important

You'll Learn

Figure 16-7 Your muscles comein many shapes and sizes. Even simplemovements require the coordinateduse of several muscles. Do you thinkmost of your muscles are voluntaryor involuntary? Why?

✔Reading Check

What is a muscle?

Sartorius

A The smallest mus-cle is located insidethe ear. It’s calledthe stapedius.

B There are over 20muscles in the face.

C The longest muscleis called the sarto-rius. It stretchesfrom the hip to theknee.

16-2 THE MUSCULAR SYSTEM 447

Prepare

PreplanningRefer to the Chapter Orga-nizer on pp. 438A–B.

1 Motivate

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46

46

ROBOTICSMany science fiction films portray robots as companions to the characters

in the movies. However, robots are now commonly used in industry to per-

form jobs that were once done by people. Unlike the robots frequently

shown in movies, these industrial robots do not look anything like people or

animals and they usually do not carry on friendly conversation.

1. What types of jobs might a robotic arm be suited to?2. What are the advantages and disadvantages of using robotic arms instead

of people to do a job?3. How is the way the robotic arm works and moves similar to the way a

human arm works and moves?


Grab

Case

Arm

Floodlight

Closed-circuittelevision camera

Tracks for movingover rough ground

Refer to TheMuscular System on pp. 438E.

ontent Background

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Activity Worksheets, pp. 87–88, 89

Enrichment, p. 46

Laboratory Manual, pp. 91 –94

Multicultural Connections, pp. 31–32


Transparencies

Teaching Transparency 32

Science Integration Transparency 16 L2

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Resource Manager

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Activity

16•1


What You’ll InvestigateWhat are the differences in the bone structures

of land animals and flying animals?

Goals• Learn the parts of a bone.• Observe the differences between the bones of

land animals and those of flying animals.

Procedure 1. Copy the data table and use it to record your

observations.2. Obtain a beef bone and a chicken leg bone

that have been cut in half along the length fromyour teacher.

3. Observe the bones with a hand lens.4. Identify the periosteum, compact bone,

spongy bone, and the remains of any marrowthat may be present.

5. In your Science Journal, draw a diagram ofthe bones and label their parts.

6. In the data table, write down any observationsthat you make.

7. Try to bend the bones to determine their flexibility.

Conclude and Apply1. Do your data indicate any adaptations for flight

in the bones?2. Infer which type of bone would require more

force to move? Explain why.3. How do the structures of the two types of bone

tissue aid in their function?4. Which type of bone tissue is more flexible?

Observing BonesTo move, animals must overcome the force of gravity. A

skeleton aids in this movement. Land animals need skele-tons that provide support against gravity. A flying animal needs a skeleton that provides support yet also allows it to overcomethe pull of gravity and fly. Bones are adapted to the functionsthey perform. Find out if there is a difference between the bonesof a land animal and those of a flying animal.

Activity 16 1

Materials• Beef bones (cut in half

lengthwise)• Chicken leg bone (cut in

half lengthwise)• Hand lens• Paper towels

Using Scientific MethodsUsing Scientific Methods

Description of Description ofPart Beef Bone Chicken Bone

PeriosteumCompact boneSpongy boneMarrow

Bone Features

Chicken bone

Beef bone


Purpose

Kinesthetic Students willobserve, identify, and de-

scribe the parts of a beef and achicken bone. Identify the charac-teristics of each bone that make itadapted for movement on land orin the air.

Process Skillsobserving, inferring, communi-cating, making and using tables,comparing and contrasting

Time45 to 50 minutes

MaterialsHave a butcher cut the bones in

half lengthwise. If possible, providea cross section of each bone type.

Safety PrecautionsCaution students to use extreme

care when using sharp instrumentssuch as a scalpel. Care should betaken when handling the cutbones, because the edges may be sharp. Cook bones first todestroy pathogens such asSalmonella.

Teaching StrategiesHave students note the

comparative mass and internalstructure of each kind of bone.

COOP LEARNELLL2

Gifted Domestic turkeys do not fly. Wildturkeys fly for short distances. Assign stu-dents the task of finding out why turkeys aresuch poor fliers. L3

Inclusion StrategiesInclusion Strategies

Answers to Questions1. The lighter weight of the

chicken bones is an adaptationto flight. Birds known for soar-ing and gliding have lightbones.

2. The denser, more compactbeef bone requires more forceto move than the lighter-weightchicken bone does.

3. The denser, compact beefbone provides support formovement on land; the less-dense, hollow chicken bone is suited for movement through air.

4. the chicken bone tissue

Process Show students pictures of the skele-tons of a penguin and a hawk. Have them identifywhich bird is probably a good flier. Use Perfor-mance Assessment in the Science Class-room, p. 17.

Assessment

Study Guide, p. 63


Human Body Levers

ISUALIZINGV

ISUALIZING

G

V ISUALIZINGV

E

F

F

L

L

A First-Class LeverA first-class lever has the ful-crum between the load and theeffort force. In your body, theskull pivots on the top vertebraas neck muscles raise yourhead up and down.

B Second-Class LeverA second-class lever hasthe load between the ful-crum and the effort force.Raising the body up onyour toes occurs when theleg muscles pull on the legand foot.

E

C Third-Class LeverA third-class lever has theeffort force between thefulcrum and the load. Yourleg works like a lever whenyou move. The contractingmuscle is the force thatmoves the bones of yourleg at the knee.

F

L

E

E

F

L

E

L

F

Effort force

Load

Fulcrum

E

F

L

EF L

Figure 16-9 Your body usesall three types of levers for variousmovements.


VideodiscGlencoe Science VoyagesInteractive Videodisc—LifeSide 2, Lesson 7 Health Is Just aHeartbeat Away

!9B[:LáÑ"23156Refer to Videodisc TeacherGuide for additional bar codes.

Teacher FYIThe three classes of levers

can be demonstrated by themovements of the foot. First-class—the movement of thefoot when it presses on thebrake pedal of a car. Second-class—the movement of thefoot when raising on tiptoes.Third-class—the movementof the foot when raising onthe heels.

EnrichmentHave students research in-

formation about various dis-orders of joints such as bursi-tis, arthritis, sprains, anddislocations that cause painwhen body parts are moved.A brief report can be preparedfor the class.

ActivityHave students experiment

using a ruler and a smallblock of wood to become fa-miliar with the placement ofthe fulcrum and the move-ment of the lever in each ofthe three classes of levers.

Hyoid Bone Have students write a briefreport on the hyoid bone located in theanterior part of the neck. It is the onlybone in the body that is not part of a jointwith another bone.

Figure 16-9 Using this figure as a refer-ence, have students give examples of ob-jects that act as levers. Examples of first-class levers include seesaws and scissors.Second-class levers include wheelbar-rows and some nutcrackers. Third-classlevers include baseball bats and brooms.

LearningVISUAL

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Everyone has had sore,overworked muscles. Havestudents recall that the sore-ness often is in muscles thataren’t conditioned.

2 TeachDiscussion

Why aren’t all muscles vol-untary? It would be impossiblefor a person to think about all thebody functions that require mus-cle action—breathing, heartbeating, stomach churning, andso on.

Levers are one kind of simple ma-chine. Machines make work easierby decreasing the amount offorce, transferring the amount offorce, or changing the direction offorce.

Caption AnswersFigure 16-7 (See p. 447.) voluntary; volun-tary muscles control all of the skeleton’s bonesFigure 16-8 The fulcrum is the place of at-tachment of the two blades.

History Archimedes was a mathematicianand scientist in ancient times. He was firstto explain the mathematics and science in-volved in levers. He is quoted as saying,“Give me but a place to stand, and I willmove the world.”

Across the CurriculumAcross the Curriculum

VideodiscGlencoe Science VoyagesInteractive Videodisc—LifeSide 2, Lesson 7 Health Is Just aHeartbeat Away

!9298nJ}"21522Refer to Videodisc TeacherGuide for additional bar codes.

Answer to

Reading Check ✔

(See p. 447.) A muscle is an

organ that can expand and

contract to allow movement.


Muscle ControlMuscles that you are able to control are called voluntary

muscles. Your arm and leg muscles are voluntary. So are themuscles of your hands and face. You can choose to movethem or not to move them. In contrast, involuntary musclesare muscles you can’t consciously control. You don’t have todecide to make these muscles work. They just go on work-ing all day long, all your life. Blood gets pumped throughblood vessels, and food is moved through your digestivesystem by the action of involuntary muscles. You can sleepat night without having to think about how to keep thesemuscles working.

Levers—Your Body’s Simple MachinesYour skeletal system and muscular system work together

to move your body like machine parts move. A machine is adevice that makes work easier. A simple machine does workwith only one movement. The action of muscles on bones andjoints often works like one type of simple machine called alever. A lever is defined as a rigid bar that moves on a fixedpoint, called a fulcrum. Figure 16-8 shows a common lever

being used to cut a piece of paper. Inyour body, bones are the bar, a joint

is the fulcrum, and contractionand relaxation of muscles pro-

vide the effort force to movethe body part.

Levers are classified intothree types. Examples of thethree types of levers areshown in Figure 16-9.

PHYSICS INTEGRATION

Figure 16-8 Scissors areused as a lever to cut paper. Yourfingers push down on the handleof the scissors, providing theforce. The blades of the scissorscut the paper. What is the fulcrumin this lever?

Flow Chart A flow chart helps students

logically sequence events. Students will write

major stages of the sequence in large ovals

and write sub-stages in smaller ovals under

the larger ovals. Have students design a flow

chart for a concept in this section.

Sample flow chart:

For additional help doing this ac-tivity at home, see the corre-sponding pages in the Home Involvement booklet.

Purpose

Kinesthetic Students willobserve the coordinated

work of muscle pairs.

Materials

Use Figure 16-11.

Teaching StrategiesHave students feel the muscles

in their arms as they contract andrelax.

Analysis1. two—biceps and triceps2. the biceps

Process Have students use achart on the muscular system andestimate the percent of body massthat is muscle tissue. UsePerformance Assessment inthe Science Classroom,p. 29.

ELLL2

Assessment



Cardiac muscle is found only in theheart. Like smooth muscle, cardiac musclealso is involuntary. As you can see fromFigure 16-10B, cardiac muscle has stria-tions like skeletal muscle. Cardiac musclecontracts about 70 times per minute everyday of your life.

Muscles at WorkSkeletal muscle movements are the

result of pairs of muscles working together.When one muscle of a pair contracts, theother muscle relaxes, or returns to its origi-nal length. For example, when the muscleson the back of your upper leg contract, theypull your lower leg back and up. Musclesalways pull. They never push. When youstraighten your leg, the back muscles relaxand the muscles on the front of your upperleg contract. Compare how the muscles ofyour legs work with how the muscles ofyour arms work, as shown in Figure 16-11.

Muscle Action and EnergyWhen you straightened your leg, your

muscles used energy. Muscles use chemicalenergy in glucose. As the bonds in glucosebreak, chemical energy changes to mech-anical energy and the muscle contracts.

Bicepsrelax

Tricepsrelax

Tricepscontract

Bicepscontract

Figure 16-11 When the biceps of the upper arm contract, the lowerarm moves upward. When the tricepsmuscles on the back of the upper armcontract, the lower arm moves down.What class of lever is shown here?

Observing Muscle Pairs at Work

Procedure

1. Find out which muscles are used to move your arm.

2. Stretch your arm out straight. Bring your handto your shoulder, then down again.

3. Use the muscles shown in Figure 16-11 todetermine which skeletal muscles in your upperarm enable you to perform this action.

Analysis

1. How many muscles were involved in thisaction?

2. Which muscle contracted to bring the forearmcloser to the shoulder?

Sedimentary rockforms.

Heat and pressureare applied

Metamorphicrock forms

grains are flattenedand aligneddeposition cementation

magmanearby

overlyinglayers

Guided Reading Strategy

Caption AnswerFigure 16-11 first-class lever

Teacher FYISkeletal muscles form a

large proportion of the bodymass. Therefore, even at restthey produce about 40 per-cent of body heat. Shiveringand physical exercise can in-crease the production of heatto double the amount.

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Types of Muscle TissueThree types of muscle tissue are found in your body: skele-

tal, smooth, and cardiac. Skeletal muscles are the musclesthat move bones. They are attached to bones by thick bands oftissue called tendons. Skeletal muscles are the most numerousmuscles in the body. When viewed under a microscope, skele-tal muscle cells look striped, or striated (STRI ayt ud). You cansee the striations in Figure 16-10A. Skeletal muscles are vol-untary muscles, which means you can control their use. Youchoose when to walk or not to walk. Skeletal muscles tend tocontract quickly and tire easily.

The remaining two types of muscles, shown in Figure 16-10B and C, are involuntary. Smooth muscles are non-striated, involuntary muscles that move many of your inter-nal organs. Your intestines, bladder, and blood vessels aremade of one or more layers of smooth muscles. These mus-cles contract and relax slowly.


Because of regularexercise during thetrack season, Hopewas able to reduceher at-rest pulse ratefrom 76 beats perminute to 66. Esti-mate how many beatsHope is saving herheart muscle per day.Calculate the percentof savings.

Figure 16-10 There are threetypes of muscle tissue—skeletalmuscle, cardiac muscle, andsmooth muscle.

B Cardiac muscle is foundonly in the heart. The mus-cle tissue has striations.

C Smooth muscle is found in many of your internalorgans, such as theintestines. The muscle tis-sue is nonstriated.

Magnification: 400�



A Skeletal muscles movebones. The muscle tissueappears striped, or striated.


10 beats/minute � 60 min-utes/hour � 24 hours/day �14 400 beats/day

�1706

bbeeaattss� � 100% � 13%

Teacher FYIRemind students that they

have no more muscle fibersnow than when they wereborn. Muscle fibers grow inlength and width, but not innumbers.

3 AssessCheck for UnderstandingDiscussion Ask, “How canyou tell whether a muscle isvoluntary?”The muscle can be moved bythinking about it.

Name muscles and have stu-dents tell whether they arevoluntary or involuntary.

ReteachVisual-Spatial Havestudents make flash-

cards with names of body organs that require muscle ac-tion. On the reverse side ofeach card, identify the type ofmuscle (skeletal, smooth, orcardiac) involved.

Extension

For students who havemastered this section, use theReinforcement and Enrich-ment masters.

L2

Use the Flex Your Brain activity to have students explore MUSCLE.

Flex Your BrainFlex Your Brain

Chemistry Structures within musclefibers contain thick filaments of the proteinmyosin and thin filaments of the proteinactin. When a muscle is activated, the chem-ical adenosine triphosphate (ATP) is brokendown, resulting in the release of largeamounts of energy. The energy causes theactin and myosin filaments to slide over eachother and the muscle contracts.


Activity

16•2Using Scientific MethodsUsing Scientific Methods

Observing MuscleMuscles can be identified by their appearance. In this activity,

you will make observations to distinguish among the threetypes of muscle tissue.

What You’ll InvestigateYou will learn how to distinguish among the

three types of muscle tissue. What do differenttypes of muscles look like?

Goals• Examine three types of muscle tissue.• Examine muscle fibers.

Procedure 1. Copy the data table and use it to record your

observations.2. Using the microscope, first on low power and

then on high power, observe prepared slidesof three different types of muscle.

3. In the data table, draw each type of muscle thatyou observe.

4. Obtain a piece of cooked turkey leg from yourteacher. Muscle tissue is made up of groups ofcells held together in fibers, usually by a trans-parent covering called connective tissue.

5. Place the turkey leg in the dissecting pan. Usethe forceps to remove the skin. Locate andtease apart the muscle fibers.

6. Use a hand lens to examine the muscle fibersand any connective tissue you see in theturkey leg.

7. Draw and measure five turkey leg fibersand describe the shape of these muscle fibers.

Conclude and Apply1. How are muscle fibers arranged in the pre-

pared slides?2. Predict how the shape of a muscle fiber

relates to its function.3. Can you conclude that striations have any-

thing to do with whether a muscle is vol-untary or involuntary? Explain.

Activity 16 2

Types of Diagram Length DescriptionMuscle of Muscle of Fibers of Fibers

Skeletal

Cardiac

Smooth

Muscle Types


Materials• Prepared slides of

smooth, skeletal, and car-diac muscles

*detailed posters of thethree types of muscle

• Microscope• Cooked turkey leg or

chicken leg• Dissecting pan or cutting

board• Dissecting probes (2)• Hand lens

*Alternate Materials

Student drawings shouldresemble photos inFig. 16-10.

Lengthswill vary.1 cm, 2.5 cm, 1.5 cm,0.75 cm

Fibers arelong andtapered atends.


Purpose

Visual-Spatial Studentswill observe and identify

parts of skeletal muscle anddescribe how muscle is attached tobone.

Process Skillsobserving, identifying, measuring,inferring

Time45 to 50 minutes

Safety PrecautionsCaution students to be careful

handling the dissecting probe andto wash their hands with soapwhen the activity is completed.

Teaching StrategiesCooked chicken legs can be

used, but it may be more difficult tosee certain parts.Troubleshooting Cautionstudents to use probes carefullywhen tearing the turkey tissue.They should spread out the tissueas finely as possible and notice thetapered ends of the muscle.

Answers to Questions 1. Accept all reasonable descrip-

tions. Most will reply that thefibers lay side by side along thelength of the bone.

2. The fiber is long and thicker inthe center than it is at the ends.When a muscle contracts, itbecomes even thicker in thecenter, but the ends stay aboutthe same.

3. No; cardiac and skeletal arestriated, but cardiac is involun-tary and skeletal is voluntary.

PCOOP LEARNELLL2

Performance To further assess the students’understanding of muscle, have them examine apiece of cooked turkey heart and describe thecharacteristics of the muscle. Use PerformanceAssessment in the Science Classroom,p. 25.

Assessment

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When the supply of glucose in a muscle is used up, the mus-cle becomes tired and needs to rest. During the restingperiod, the muscle is resupplied with glucose via the blood-stream. Muscles also produce thermal energy when they con-tract. The heat produced by muscle contraction helps to keepyour body temperature constant.

Over a period of time, muscles can become larger orsmaller, depending on whether or not they are used. You cansee in Figure 16-12 that skeletal muscles that do a lot of work,such as those in your writing hand or in the arms of a personon crutches, become larger and stronger. In contrast, if youwatch TV all day, your muscles will become soft and flabby

and will lack strength. Muscles that aren’t exercisedbecome smaller in size.


1. What is the function of the muscular system?2. Compare and contrast the three types of muscle.3. What type of muscle tissue is found in your heart?4. Describe how a muscle attaches to a bone.5. Think Critically: What happens to your upper arm

muscles when you bend your arm at the elbow?

6. Skill BuilderSequencing Sequence the activities that take

place when you bend your leg at the knee. If you needhelp, refer to Sequencing in the Skill Handbook on page 678.


Write a para-graph in your

Science Journal identi-fying the three forms of energy involved in a muscle contraction.Describe what relation-ship this has to being awarm-blooded animal.

INTEGRATIONCHEMISTRY

Muscle ProteinMuscle cells contain a pro-tein called myoglobin that issimilar to hemoglobin in redblood cells. Hemoglobin is a red pigment that carriesoxygen. From this informa-tion, what can you inferabout myoglobin?

Figure 16-12 The numberof muscles in an adult does notincrease with exercise andbody building. The cells simplyget larger.


4 CloseProficiency PrepUse this quiz to check stu-dents’ recall of section content.

1. How do muscles work?contraction

2. What type of musclesmove food through thedigestive system? smooth(involuntary)

1. movement2. Skeletal and cardiac have

striations; however, thefirst is voluntary and thesecond is involuntary.Smooth and cardiac areinvoluntary; however,smooth muscle is not stri-ated and cardiac is.

3. cardiac4. Thick bands of tissue

called tendons attachmuscles to bone.

5. Think Critically Musclesin the front (biceps) con-tract, while muscles in theback (triceps) relax.


AssessmentPerformance Assess students’ abilities tosequence by having them order the activi-ties that take place when the ankle is flexed.Use Performance Assessment in the Sci-ence Classroom, p. 91.

6. Skill BuilderThe muscles on the undersideof your thigh contract, and the

bottom part of your leg is drawn towardthe thigh. At the same time, the muscleson the top of the thigh relax andlengthen.

Myoglobin is a red pigment thatmight be similar to hemoglobin instructure and, therefore, might beable to carry oxygen.

Entries should list thethree forms of energy aschemical, mechanical, andthermal. It is the thermalenergy of muscle contrac-tions that helps maintainthe constant body heat ofwarm-blooded animals.

SkinThe Body’s Largest Organ

Your skin is the largest organ of your body. Much of theinformation you receive about your environment comesthrough your skin. You can think of your skin as your largestsense organ.

Skin StructuresSkin is made up of two layers of tissue, the epidermis and

the dermis. You can see in Figure 16-13 that the epidermis isthe surface layer of your skin. The cells on the top of the epi-dermis are dead. Thousands of these cells rub off every timeyou take a shower, shake hands, blow your nose, or scratchyour elbow. New cells are constantly produced at the bottomof the epidermis. These new cells are moved up and eventu-ally replace the ones that are rubbed off. Cells in the epider-mis produce the chemical melanin. Melanin (MEL uh nun) isa pigment that gives your skin color. The more melanin, thedarker the color of the skin. Melanin increases when yourskin is exposed to the ultraviolet rays of the sun. If someonehas few melanin-producing cells, little color gets deposited.These people have less protection from the sun. They burnmore easily and may develop skin cancer more easily. ✔

16 3

The differences between the epidermis and dermis ofthe skinThe functions of the skinHow skin protects the bodyfrom disease and how it healsitself

Vocabularyepidermismelanindermis

Skin plays a vital role in protecting your body againstinjury and disease.


It's Important

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It's Important

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It's Important

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Sweat gland pore

Nerve ending

Sweat gland

Blood vessels

Nerve endings Oil glandHair follicle

Fat deposit

Dermis

Epidermis

Hair shaft

16-3 SKIN 455

Figure 16-13 Hair, nails, and sweat and oilglands are all part of your body’s largest organ.What two layers of tissue make up your skin?

✔Reading Check

What is melanin?

16-3 SKIN 455

Prepare

PreplanningRefer to the Chapter Orga-nizer pp. 438A–B.

1 Motivate

SECTION 16•3

Bellringer




47

47

PEEL IT OFF!Many of the fruits and vegetables we eat as food are enclosed in an outer

covering. We remove these coverings from the food before we eat it. For

example, oranges, tangerines, and grapefruits are enclosed by rinds. Most

nuts are enclosed in shells. Other fruits and vegetables, such as bananas and

potatoes, are covered with peels.

1. What role do the coverings of fruits and vegetables provide to the plants?

2. What organ of the human body plays a role similar to the peel of a banana

or the rind of an orange?


Refer to Skinand Hair on p. 438F.

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Caption AnswerFigure 16-3 epidermis, dermis



Activity Worksheets, p. 90

Critical Thinking/Problem Solving, p. 16

Enrichment, p. 47


Study Guide, p. 64 ELLL1

L2

L3

L2

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Resource ManagerAnswer to

Reading Check ✔

a pigment that gives your skin

color.

Science Society&

Frankensteinby Mary ShelleyIn this chapter, you’ve studied the structure of the bones andmuscles of your own body. Many authors have written aboutthe beauty and complexity of the human form. In the clas-sic book Frankenstein, author Mary Shelley (inset) paystribute to the science of anatomy in the story about a sci-entist, Dr. Frankenstein, who creates life from lifelessbody parts. The 1931 movie, based on the book, por-trayed the Frankenstein “monster” as seen in the photo,right. In the following excerpt from the book, Shelleydetails how Dr. Frankenstein slowly pieces together hiscreation.

As the minuteness of the parts formed a great hin-drance to my speed, I resolved, contrary to my firstintention, to make a being of a gigantic stature,that is to say, about eight feet in height, andproportionately large. After having formed thisdetermination and having spent some monthsin successfully collecting and arranging mymaterials, I began….

His limbs were in proportion, and I had selected his features as beautiful.Beautiful!…His yellow skin scarcely coveredthe work of muscles and arteries beneath; hishair was of a lustrous black, and flowing; histeeth of a pearly whiteness; but these luxuriancesonly formed a more horrid contrast with his wateryeyes that seemed almost of the same colour as the dunwhite sockets in which they were set, [with] his shriveledcomplexion and straight black lips.

Many people agree that the human body is a sort of liv-ing machine. The creation of the monster’s face is like thestory of a technician piecing together a complex machine.Mary Shelley’s vivid descriptions have been compared toscientific writing. Which parts of this excerpt do you thinkwould be similar to the writing of someone detailing thestructure of the human body?

Choose a living organism. Imagineyou are a scientist trying todescribe your organism to otherscientists. Try to paint a vividpicture of the organism bydescribing its features in detailin your Science Journal.

ScienceJOURNAL

Reading Writingin Science

&

454 CHAPTER 16 BONES MUSCLES AND SKIN


Mary Shelley (1797–1851) isbest known for her classicwork, Frankenstein, The Mod-ern Prometheus, perhaps themost widely known horrornovel. Mary WollstonecraftGodwin Shelley, born in Lon-don, was the daughter ofphilosopher William Godwinand feminist writer MaryWollstonecraft. With no for-mal training in writing, Shel-ley began Frankenstein in1816 at the age of nineteen.The spellbinding tale of horrorand romance has since beenpopularized by many motionpictures and television pro-grams. Shelley wrote severalother books in her lifetime, in-cluding a historical novelValperga: The Life and Adven-tures of Castruccio, Prince ofLucca (1823) and The Last Man(1826). The latter is consideredby many to be her finest work.

Teaching Strategies• Have students discuss the

analogy of the human bodyas a living machine.

• Have students constructsimple marionette puppetsof cardboard and yarn. Stu-dents will gain an under-standing of how skeletal andmuscular systems work bytrying to simulate the majorjoints and muscle groups ofthe body.

• Initiate a discussion about fa-mous athletes who can per-form exciting and dazzling

feats. Have students write a short essayabout the athlete who most impressesthem. Ask students to write why they areimpressed with the athlete’s skills.

For Additional Information• Levine, George and Knoepflmacher, U.C.,

eds. The Endurance of Frankenstein. Univer-sity of California Press, 1979.

• Gould, Steven Jay. The Panda’s Thumb.W.W. Norton, 1980.

ontent Background

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CC

Answers will vary depend-ing on the organism chosen.

Students should use vivid language to de-scribe the color, size, shape, and structure ofthe organism. However, descriptions shouldbe limited to actual features of the organism.P

Page 454: 5a, 5bPage 455: 5a, 5b


16-3 SKIN 457

When the blood vessels dilate, pores leading to the sweatglands in the skin open. Perspiration, or sweat, moves outonto the skin. Heat moves from inside the body to thesweat on the body’s surface. The body then cools as thesweat evaporates. This system balances heat that has beenproduced by muscle contractions.

The fifth function of the skin is to excrete wastes. Sweatglands release water, salt, and a protein product called urea.If too much water and salt are released during periods ofextreme heat or physical exertion, you might faint.

Injury to the SkinDespite its daily dose of scratching, burning, ripping

and exposure to harsh conditions, the skin still contin-ues to produce new cells in its outer layer, the epider-mis, and repair tears in its inner layer, the dermis.When an injury occurs in the skin, as shown in Figure 16-15, disease-causing organisms can enter the body rapidly. An infection may result.

However, if there is injury to large areas of the skin, suchas burning or rubbing away of the epidermis, there are nolonger any cells left that can divide to replace this lost layer.In severe cases of skin loss or damage, nerve endings andblood vessels in the dermis are exposed. Water is lost rapidlyfrom the dermis and muscle tissues. Body tissues are exposedto bacteria and to potential infection, shock, and death.

1. Compare and contrast the epidermis and dermis.2. List the five functions of skin.3. How does skin help prevent disease in the body?4. Think Critically: Why is a person who has

been severely burned in danger of dying fromloss of water?

5. Skill BuilderConcept Mapping Make an

events chain concept map to show how skinhelps keep body temperature constant. If youneed help, refer to Concept Mapping in theSkill Handbook on page 678.

Database Use referencesto research common skinlesions. Include warts, pso-riasis, burns, acne, scrapewounds, insect bites, freck-les, athlete’s foot, andother lesions. Use yourcomputer to make a data-base. Classify the lesions asflat, depressed, or elevated.If you need help, refer topage 697.


Figure 16-15 Injuries to yourskin make it easier for bacteria andviruses to infect the body.

16-3 SKIN 457

AssessmentProcess Have students construct modelsof skin with and without fur to determinethe insulating qualities of fur. Use Perfor-mance Assessment in the Science Class-room, p. 51.

5. Skill BuilderStudents’ sequence should ap-proximate: Body becomes hot

or warm → blood vessels expand →sweat moves out onto skin → bodycools as sweat evaporates.

ReteachLinguistic Have stu-dents prepare an outline

of skin functions correlatedwith the skin layers.

ExtensionFor students who have

mastered this section, use theReinforcement and Enrich-ment masters.

4 Close

L2

Classification of skin conditions:flat—frecklesdepressed—severe burns,

scrape woundsathlete’s foot;

elevated—warts, psoriasisacne, insect bitesP

1. The epidermis is the thin,outer layer of skin. It co-tains melanin. The dermisis under the epidermis. Itis thicker and containsmany blood vessels,nerves, and sweat glands.

2. protects, regulates bodytemperature, excreteswastes, serves as sensoryorgan, forms vitamin D

3. As long as it is unbroken,skin prevents pathogensfrom entering the body.Glands in the skin secretefluids that destroy bacteria.

4. Think Critically Theyhave lost the protectionfrom loss of water.


Page 456: 5a, 5b, 7a, 7c,7ePage 457: 5a, 5b, 7b


The dermis is the layer of tissue underthe epidermis. This layer is thicker thanthe epidermis and contains many bloodvessels, nerves, and oil and sweat glands.Notice in Figure 16-13 that fat cells arelocated under the dermis. This fatty tissueinsulates the body. When a person gainstoo much weight, this is where much ofthe extra fat is deposited.

Functions of the SkinYour skin is not only the largest organ of

your body, it also carries out several majorfunctions, including protection, sensoryresponse, formation of vitamin D, regula-tion of body temperature, and the excre-tion of wastes. Of these functions, the mostimportant is that skin forms a protectivecovering over the body. As a covering, itprevents both physical and chemicalinjury, as well as disease. Glands in the

skin secrete fluids that damage or destroy some bacteria.Skin also prevents excess water loss from body tissues.

The skin also serves as a sensory organ. Specialized nervecells in the skin detect and relay information about tempera-ture, pressure, and pain. Some of the sensors are shown inFigure 16-13. Because of these sensors, you are able to detectthe softness of a cat, the sharp point of a pin, or the heat of afrying pan.

A third vital function of skin is the formation of vitamin D.Vitamin D is essential for your good health because it helpsyour body to absorb calcium from the food you eat. Smallamounts of this vitamin are produced in the epidermis in thepresence of ultraviolet light from the sun.

Heat and Waste ExchangeYour skin plays an important role in helping to regulate

your body temperature. Humans, unlike the fur-bearing ani-mal in Figure 16-14, have very little hair to help them regu-late body temperature. Hair is an adaptation that usuallyhelps control body temperature. In humans, blood vessels inthe skin can help release or hold heat. If the blood vesselsexpand or dilate, blood flow increases and heat is released.Less heat is released when the blood vessels constrict.

The dermis has about 3 million sweat glands. Theseglands also help regulate the body’s temperature.

Figure 16-14 All animalsmust be able to control body tem-perature. Insulation of an animal’sbody occurs when the fur is raised.What happens to fur when theanimal’s body temperature ishigh?

Recognizing Why You Sweat

Procedure

1. Examine the epidermis and the pores of yourskin using a hand lens.

2. Place a small, clear plastic, sandwich-size bagon your hand. Use tape to keep the bag closed.

3. Quietly study your text for 10 minutes, thenlook at your hand.

4. Observe what happened to your hand while itwas in the bag.

Analysis

1. Identify what formed inside the bag. Where didthis substance come from?

2. Why is it necessary for this substance to form,even when you are inactive?




Recall the characteristics ofmammals from an earlierchapter. One characteristic isa hair-covered body. Humanslack this extensive covering

2 TeachQuick Demo

Kinesthetic Have eachstudent pat a wet cotton

ball onto the wrist. Then havethem gently blow on the wetsurface. The evaporation re-moves body heat. Relate thisexperience to the evaporationof perspiration from the skinduring hot weather.

3 AssessCheck for UnderstandingUsing an Analogy

The hypothalamus in thebrain acts as a thermostat. Itreceives its temperature read-ings from the skin and relaysmessages to body parts tomaintain a constant tempera-ture.

Caption AnswerFigure 16-14 The fur is shed.

ELLL1

Physics Have students survey local manu-facturing facilities to find out how many useindustrial robots. Arrange for students to visitone facility to see how the robots are used.Find out if any have an artificial skin to beable to sense different textures.


Performance Have students predict if moresweat would accumulate in the bag under a variety of conditions. Have them designexperiments to test their predictions. UsePerformance Assessment in the Science Classroom, p. 23.

Assessment

Purpose

Visual-Spatial Studentswill infer that a liquid

formed in the bag is evaporatedwater from the skin.

Materialsclear plastic bag, tape, hand lens

Analysis1. water; from the skin2. The evaporation cools the skin

surface and helps maintain aconstant body temperature.

ELLL2

CHAPTER 16 REVIEWING MAIN IDEAS 459

✔Reading Check

Review the levers in

Figure 16-9. Then, iden-

tify another example

that could have been

used to illustrate each

class of lever.

Section

16-3 SKIN

The skin is the largest organ of the body andis in direct contact with the environment. This bodycovering gives protection, helps retain moisture,aids in the formation of vitamin D, and assists inregulating the body’s temperature. How do sweatglands and blood vessels in the skin help thebody maintain an even temperature?

Section

16-2 MUSCLES

Muscles can only contract and relax to producemovement of bones and body parts. Muscles do not stretch.Skeletal muscle movements are voluntary and movebones. Smooth muscle movements are involuntary andcontrol internal organs. Cardiac muscles control the in-voluntary contractions of the heart. How are skeletalmuscles attached to the bones they move?

CHAPTER 16 REVIEWING MAIN IDEAS 459

Answers to Questions

Section 16-1Bones and Muscles Theskeletal and muscular systemwork together to allow thebody to move.Skeletal System The shapeof long bones can supportweight. Small and irregularbones can articulate easily, al-lowing for movement. Flatbones give shape and protec-tion to body areas.

Section 16-2Muscles They are attachedto the bones they move bythick bands of tissue called tendons.

Section 16-3Skin Sweat glands can se-crete perspiration that evapo-rates from the skin and coolsthe surface. Blood vessels inthe skin can dilate and releaseheat, or they can constrict andconserve heat.

Portfolio Encourage students to place intheir portfolios one or two items of whatthey consider to be their best work. Exam-ples include: • Activity 16-2, p. 453 • Science Journal, p. 454• Using Computers, p. 457

Performance Additional performance as-sessments may be found in PerformanceAssessment and Science Integration Ac-tivities. Performance Task Assessment Listsand rubrics for evaluating these activitiescan be found in Glencoe’s Performance As-sessment in the Science Classroom.

P

Assessment

CD-ROMGlencoe Science VoyagesInteractive CD-ROMChapter Summaries and QuizzesHave students read theChapter Summary then take theChapter Quiz to determinewhether they have masteredchapter content.

Chapter

16ReviewingMain Ideas

For a preview of thischapter, study this

Reviewing Main Ideasbefore you read the chapter.After you have studied thischapter, you can use theReviewing Main Ideas toreview the chapter.

The GlencoeMindJogger,Audiocassettes,and CD-ROM

provide additionalopportunities for review.

Chapter Reviewing Main IdeasChapter Reviewing Main Ideas16


SKELETAL SYSTEM

Bones are complex, living structuresthat have a variety of functions. They pro-

tect other organs, give support, makeblood cells, store minerals, and provide for

muscle attachment that allows movement. Theplaces where bones meet are called joints.Some joints are immovable, other jointscan move slightly, and others can movea lot. Consider the difference betweenthe movement of the toes and themovement of the wrist. How do theshapes of bones often relate totheir function?

Section

16-1 BONES AND MUSCLES

Bodies have a great range of movement, from pick-ing up a feather to kicking a soccer ball, because of coordi-nated activities of the bones and muscles. In addition, theseorgans give shape to bodies, which arewrapped with a remarkable membrane,the skin. What two systems worktogether to allow body movement?


Reviewing Main Ideas canbe used to preview, review,reteach, and condense chap-ter content.

Preview

Linguistic Have stu-dents try to answer the

questions in their ScienceJournals. Use student an-swers as a source for discus-sion throughout the chapter.

Review

Interpersonal Havestudents answer the

questions on separate piecesof paper and compare theiranswers with those of otherstudents in the class.

Reteach

Visual-Spatial Havestudents look at the il-

lustrations on these pages.Ask them to describe detailsthat support the main ideas ofthe chapter found in the state-ment for each illustration.

Auditory-Musical If

time does not permit

teaching the entire chap-

ter, use the information on

these pages along with the

chapter Audiocassettes to

present the material in a

condensed format.

OUT OF

TIME?

Bone in Different People Medical sci-entists have found that the bones of people ofAfrican descent contain more minerals thanbones of Hispanics and Caucasians. The exactreason for this difference is not known. How-ever, people of African descent apparently con-tain more calcium and potassium in their bonesthan other people. As a result, they also tend tohave slightly larger, heavier bones. Children of

African descent tend to have fewer and less se-rious bone fracture injuries, and older adults ofAfrican descent tend to have fewer and less se-rious fractures of their hip bones.

Knowing the composition of bone, includingthe mineral content, doctors may be more ef-fective in their diagnosis and treatment ofbone disease in people from different ethnicbackgrounds.

Cultural DiversityCultural Diversity

TEST-TAKING

CHAPTER 16 ASSESSMENT 461

Test-Taking Tip

Work Weak Muscles, Maintain StrongOnes It’s sometimes difficult to focus onall the concepts needed for a test. So, askyourself “What’s my strongest area?”“What’s my weakest area?” Focus mostof your energy on your weak areas. But,also put in some upkeep time in yourbest areas.

Test Practice

Use these questions to test your ScienceProficiency.

1. The skin has specialized sensory cellsthat detect and pass on information fromthe external environment to the body. Towhich group of stimuli can the skinrespond?A) touch, temperature, timeB) pressure, pain, soundC) pressure, temperature, painD) hunger, odor, temperature

2. Cartilage is a specialized tissue that cov-ers the ends of some bones. Which groupof characteristics is correctly associatedwith this tissue?A) nerves and blood vesselsB) muscles and tendonsC) fat cells and blood vesselsD) none of the above

3. The skeletal and muscular systems worktogether to move body parts like one ofthe simple machines called a lever.Which body movement is an example ofa first-class lever?A) picking up an object with your handB) raising the body up on your toesC) waving your hand up and downD) moving your head up and down

Developing Skills

If you need help, refer to the Skill Handbook.

21. Observing and Inferring: The joints in the skull of a newborn baby are flexi-ble, whereas those of a 17 year old havegrown together tightly. Infer why theinfant’s skull joints are flexible.

22. Designing an Experiment: Design anexperiment to compare the heartbeat ratesof athletes and nonathletes in your class.

23. Hypothesizing: Make a hypothesisabout the distribution of sweat glandsthroughout the body. Are they evenlydistributed?

24. Concept Mapping: Construct an eventschain concept map to describe how abone heals.

25. Hypothesizing: When exposed to directsunlight, dark-colored hair absorbs moreenergy than light-colored hair. Given thisinformation, make a hypothesis as to themost adaptive colors for desert animals.

Release into Blood Stream

Build Bone

Break Down Bone

Release into Blood Stream

Build Bone

Break Down Bone

Osteoblasts

Osteoclasts

Calcium Phosphorous

AssessmentAssessment

CHAPTER 16 ASSESSMENT 461

The Test-Taking Tip waswritten by The Princeton Re-view, the nation’s leader intest preparation.

1. C2. D3. D

Developing Skills

21. Accept all reasonable an-swers. Flexible joints aregenerally thought to behelpful during birth.

22. The experiment shouldinvolve comparing boththe resting and exercisingheart rates.

23. Sweat glands are notevenly distributed on theskin. This is known be-cause, when exercising,sweat is found in certainareas (face, underarms)and not others.

24. See concept map on reduced student page.

25. Light-colored hair will re-flect more solar radiationthan dark hair. Less heatwill be absorbed.

Bonus Question

What is the differenceamong first-, second-, andthird-degree burns? First-degree burns involve only theepidermis; second-degree burnsinvolve the epidermis and der-mis; and third-degree burns ex-tend beyond the dermis into themuscle and bone.

Test Practice

The Test Practice Workbook provides studentswith practice in the format, concepts, and criti-cal-thinking skills tested in standardized exams.

Reproducible MastersChapter Review, pp. 31–32 Performance Assessment, p. 16 Assessment, pp. 61–64

Glencoe Technology

Chapter Review Software

Computer Test Bank

MindJogger Videoquiz

L2

L2

L2

Assessment Resources

Chapter

16Assessment Chapter AssessmentChapter Assessment16


10. Where are immovable joints found?A) at the elbow C) in the wristB) at the neck D) in the skull

11. What kind of joints are the knees andfingers?A) pivot C) glidingB) hinge D) ball-and-socket

12. Which vitamin is made in the skin?A) A C) DB) B D) K

13. Where are dead cells found?A) dermis C) epidermisB) marrow D) periosteum

14. What is a nutrient found in bone?A) iron C) vitamin DB) calcium D) vitamin K

15. What helps retain fluids in the body?A) bone C) skinB) muscle D) a joint

Thinking Critically

16. When might skin not be able to produceenough vitamin D?

17. What effects do sunblocks have onmelanin?

18. What would lack of calcium do tobones?

19. Using a microscope, how could you dis-tinguish among the three muscle types?

20. What function of skin in your lower lipchanges when a dentist gives you novo-caine for a filling in your bottom teeth?Why?

a. cardiac muscleb. cartilagec. dermisd. epidermise. immovable jointf. involuntary

muscleg. jointh. ligamenti. marrow

j. melanink. movable jointl. muscle

m. periosteumn. skeletal muscleo. skeletal systemp. smooth muscleq. tendonr. voluntary

muscle

Each phrase below describes a science termfrom the list. Write the term that matches thephrase describing it.

1. tough outer covering of bone2. internal body framework3. outer layer of skin4. skin pigment5. attaches muscle to bone

Checking Concepts

Choose the word or phrase that best answersthe question.

6. Which of the following is the most solidform of bone?A) compact C) spongyB) periosteum D) marrow

7. Where are blood cells made?A) compact bone C) cartilageB) periosteum D) marrow

8. Where are minerals stored?A) bone C) muscleB) skin D) blood

9. What are the ends of bones coveredwith?A) cartilage C) ligamentsB) tendons D) muscle

Using Vocabulary


Using Vocabulary

1. m2. o3. d4. j5. q

To reinforcechapter vo-

cabulary, use the Study Guidefor Content Mastery booklet.Also available are activities forGlencoe Science Voyages onthe Glencoe Science Web Site.www.glencoe.com/sec/science/ca

Checking Concepts

6. A 11. B7. D 12. C8. A 13. C9. A 14. B

10. D 15. C

Thinking Critically

16. If there is not enough ex-posure to sunlight, notenough vitamin D is pro-duced.

17. Sunblocks “mask” theskin cells and prevent fullpenetration of the sun’srays to the melanin ofthese cells.

18. Bones lacking calcium be-come too flexible andmisshapen. They are alsomore easily broken.

19. Smooth muscle is madeof individual, spindle-shaped cells in layers;skeletal muscle is made ofstriped fibers; cardiacmuscle is a branching,fiberlike structure.

20. Novocaine numbs the nerves so yourskin can no longer sense stimuli such aspressure or pain. Novocaine numbsnerves in the dermis.


Documents

UNIT4 UNIT Introducing the Unit 4 - mrwrightsclass.netmrwrightsclass.net/resources/old-7th-grade-text/chap16.pdf · motion of the body’s 68 joints. Her eyes and other sensory organs