Chapter 20 Unifying Concepts of Animal Structure and …€¦ · © 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko PowerPoint Lectures for Campbell Biology: Concepts &

© 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko

PowerPoint Lectures for

Campbell Biology: Concepts & Connections, Seventh Edition

Reece, Taylor, Simon, and Dickey

Chapter 20 Unifying Concepts of Animal

Structure and Function

How can geckos climb walls and stick to the

ceiling?

– The surfaces of gecko toes are covered by millions of

microscopic hairs.

– Each hair has a slight molecular attraction that helps it

stick to the surface.

– This adhesive relationship is an example of the

correlation between structure and function.

Introduction

© 2012 Pearson Education, Inc.

Figure 20.0_2

Chapter 20: Big Ideas

Structure and Function

in Animal Tissues

Organs and Organ

Systems

External Exchange and

Internal Regulation

Figure 20.0_3

STRUCTURE AND FUNCTION

IN ANIMAL TISSUES


20.1 Structure fits function at all levels of organization in the animal body

Anatomy is the study of structure.

Physiology is the study of function.

Animals consist of a hierarchy of levels or

organization.

– Tissues are an integrated group of similar cells that

perform a common function.

– Organs perform a specific task and consist of two or

more tissues.

– Organ systems consist of multiple organs that together

perform a vital body function.


Figure 20.1

Tissue level Muscle tissue

Cellular level Muscle cell

Organ level Heart

Organ system level Circulatory system

Organism level Many organ systems functioning together

20.2 EVOLUTION CONNECTION: An animal’s form reflects natural selection

The body plan or design of an organism

– reflects the relationship between form and function,

– results from natural selection, and

– does not imply a process of conscious invention.

Streamlined and tapered bodies

– increase swimming speeds and

– have similarly evolved in fish, sharks, and aquatic birds

and mammals, representing convergent evolution.


Video: Shark Eating a Seal Video: Galápagos Sea Lion

20_02SharkEatSeal_SV.mpg

20_02SeaLion_SV.mpg

20.3 Tissues are groups of cells with a common structure and function

Tissues

– are an integrated group of similar cells that perform a

common function and

– combine to form organs.

Animals have four main categories of tissues:

1. epithelial tissue,

2. connective tissue,

3. muscle tissue, and

4. nervous tissue.


20.4 Epithelial tissue covers the body and lines its organs and cavities

Epithelial tissues, or epithelia, are sheets of

closely packed cells that

– cover body surfaces and

– line internal organs and cavities.

Epithelial cells come in three shapes:

1. squamous—like a fried egg,

2. cuboidal—as tall as they are wide, and

3. columnar—taller than they are wide.


20.4 Epithelial tissue covers the body and lines its organs and cavities

Epithelial tissues are named according to the

– number of cell layers they have and

– shape of the cells on their apical surface.


Figure 20.4

Stratified squamous epithelium

Pseudostratified ciliated columnar epithelium

Simple columnar epithelium

Simple cuboidal epithelium

Simple squamous epithelium

Basal lamina

Underlying tissue

Apical surface of epithelium

Cell nuclei

20.5 Connective tissue binds and supports other tissues

Connective tissue can be grouped into six major

types.

1. Loose connective tissue

– is the most widespread,

– consists of ropelike collagen and elastic fibers that are strong

and resilient, and

– helps to join skin to underlying tissues.

2. Fibrous connective tissue

– has densely packed collagen fibers and

– forms tendons that attach muscle to bone.


20.5 Connective tissue binds and supports other tissues

3. Adipose tissue stores fat in large, closely packed cells

held in a matrix of fibers.

4. Cartilage

– is a strong and flexible skeletal material and

– commonly surrounds the ends of bones.

5. Bone

– has a matrix of collagen fibers

– embedded in a hard mineral substance containing calcium,

magnesium, and phosphate.

6. Blood transports substances throughout the body.


Figure 20.5

Cell nucleus

Collagen fiber

Elastic fibers

Loose connective tissue (under the skin)

Cell nucleus

Collagen fibers

Fibrous connective tissue (forming a tendon)

Fat droplets

Adipose tissue

White blood cells

Red blood cell

Plasma

Blood

Central canal

Matrix

Bone

Bone- forming cells

Cartilage- forming cells

Matrix

Cartilage (at the end of a bone)

20.6 Muscle tissue functions in movement

Muscle tissue is the most abundant tissue in most

animals.

There are three types of vertebrate muscle tissue:

1. Skeletal muscle causes voluntary movements.

2. Cardiac muscle pumps blood.

3. Smooth muscle moves walls of internal organs, such

as the intestines.


Figure 20.6

Unit of muscle contraction

Muscle fiber (cell)

Nuclei

Skeletal muscle

Muscle fiber

Nucleus

Junction between two cells

Cardiac muscle

Muscle fiber

Smooth muscle

Nucleus

20.7 Nervous tissue forms a communication network

Nervous tissue

– senses stimuli and

– rapidly transmits information.

Neurons carry signals by conducting electrical

impulses.

Other cells in nervous tissue

– insulate axons,

– nourish neurons, and

– regulate the fluid around neurons.


Figure 20.7

Dendrites

Cell body

Axon

ORGANS AND

ORGAN SYSTEMS


20.8 Organs are made up of tissues

Each tissue performs specific functions.

The heart has

– extensive muscle that generates contractions,

– epithelial tissues that line the heart chambers,

– connective tissues that make the heart elastic, and

– neurons that regulate contractions.


20.8 Organs are made up of tissues

The small intestine

– is lined by a columnar epithelium,

– includes connective tissues that contain blood vessels,

and

– has two layers of smooth muscle that help propel food.

The inner surface of the small intestine has many

fingerlike projections that increase the surface area

for absorption.


Figure 20.8

Small intestine

Lumen

Epithelial tissue (columnar epithelium)

Connective tissue

Smooth muscle tissue (two layers)

Connective tissue

Epithelial tissue

Bioengineering is seeking ways to repair or replace

damaged tissues and organs.

New tissues and organs are being grown using a

patient’s own cells.

These techniques

– remove the risk of tissue rejection and

– may someday reduce the shortage of organs available

for transplants.

20.9 CONNECTION: Bioengineers are learning to produce tissues and organs for transplants


20.10 Organ systems work together to perform life’s functions

Each organ system

– typically consists of many organs,

– has one or more functions, and

– works with other organ systems to create a functional

organism.


Figure 20.10_L

Blood vessels

Heart

Circulatory system

Respiratory system

Nasal cavity

Pharynx

Larynx

Trachea

Bronchus

Lung

Bone

Cartilage

Skeletal system

Muscular system

Skeletal muscles

Integumentary system

Hair

Skin

Nails

Urinary system

Digestive system

Urinary bladder

Small intestine

Large intestine

Kidney

Ureter

Urethra

Mouth

Esophagus

Liver

Stomach

Anus

Figure 20.10_R

Endocrine system

Thymus

Adrenal gland

Pancreas

Testis (male)

Hypothalamus

Pituitary gland

Thyroid gland

Parathyroid gland

Ovary (female)

Lymphatic and immune systems

Lymph nodes

Appendix

Bone marrow

Thymus

Spleen

Lymphatic vessels

Reproductive system

Female

Oviduct

Ovary

Uterus Vagina

Male

Seminal vesicles

Prostate gland

Vas deferens

Penis

Urethra Testis

Nervous system Brain

Sense organ (ear)

Spinal cord

Nerves

The skeletal and muscular systems support and

move the body.

The digestive and respiratory systems obtain

food and oxygen.

The circulatory system transports these

materials.

The urinary system disposes of wastes.

The integumentary system covers the body.



Figure 20.10_1

Circulatory system

Respiratory system

Nasal cavity

Blood vessels

Heart

Pharynx

Larynx

Trachea

Bronchus

Lung

Figure 20.10_4

Muscular system

Skeletal muscles

Figure 20.10_5

Urinary system

Digestive system

Urinary bladder

Small intestine

Large intestine

Kidney

Ureter

Urethra

Mouth

Esophagus

Liver

Stomach

Anus

The lymphatic and immune systems protect the

body from infection.

The nervous and endocrine systems control and

coordinate body functions.

The reproductive system produces offspring.



Figure 20.10_6

Endocrine system

Thymus

Adrenal gland

Pancreas

Testis (male)

Hypothalamus

Pituitary gland

Thyroid gland

Parathyroid gland

Ovary (female)

Figure 20.10_7

Lymphatic and immune systems

Lymph nodes

Appendix

Bone marrow

Thymus

Spleen

Lymphatic vessels

Figure 20.10_8

Nervous system Brain

Sense organ (ear)

Spinal cord

Nerves

Figure 20.10_9

Reproductive system

Female

Oviduct

Ovary

Uterus Vagina

Male

Seminal vesicles

Prostate gland

Vas deferens

Penis

Urethra Testis

20.11 CONNECTION: New imaging technology reveals the inner body

New technologies

– are used in medical diagnosis and research and

– allow physicians to examine organ systems without surgery.

X-rays help create images of hard structures such as bones and teeth.

Magnetic resonance imaging (MRI)

– takes advantage of the behavior of the hydrogen atoms in water molecules and

– provides three-dimensional images of very small structures.


Figure 20.11A

Femur

(thigh bone)

Torn meniscus

Tibia (shin bone)

A newer X-ray technology called computed tomography (CT)

– produces high-resolution images of cross sections of the body and

– can detect small differences between normal and abnormal tissues in many organs.

Positron-emission tomography (PET) helps identify metabolic processes at specific body locations.

CT and PET images can be combined for an even more informative image.

20.11 CONNECTION: New imaging technology reveals the inner body


20.12 The integumentary system protects the body

The skin consists of two layers:

1. The epidermis

– is a stratified squamous epithelium and

– forms the surface of the skin.

2. The dermis

– forms a deeper skin layer and

– is composed of dense connective tissue with many resilient elastic fibers and strong collagen fibers.

– The dermis contains hair follicles, oil and sweat glands, muscle cells, nerves, sensory receptors, and blood vessels.


Figure 20.12

Epidermis

Dermis

Hypodermis

(under the skin)

Adipose tissue

Blood vessels

Hair follicle

Oil gland

Sweat

gland

Nerve

Muscle

Sweat

pore

Hair

Skin has many functions.

– The epidermis

– resists physical damage,

– decreases water loss, and

– prevents penetration by microbes.

– The dermis

– collects sensory information,

– synthesizes vitamin D, and

– helps regulate body temperature.



Exposure of the skin to ultraviolet light

– causes skin cells to release melanin, which contributes

to a visible tan, and

– damages DNA of skin cells and can lead to

– premature aging of the skin,

– cataracts, and

– skin cancers.



Hair

– is an important component of the integumentary system of mammals,

– helps to insulate their bodies, and

– consists of a shaft of keratin-filled dead cells.

Oil glands release oils that

– are associated with hair follicles,

– lubricate hair,

– condition surrounding skin, and

– inhibit the growth of bacteria.



EXTERNAL EXCHANGE AND

INTERNAL REGULATION


20.13 Structural adaptations enhance exchange with the environment

Every organism is an open system that must

exchange matter and energy with its surroundings.

Cells in small and flat animals can exchange

materials directly with the environment.



However, as organisms increase in size, the surface

area

– is too small for the corresponding volume and

– too far away from the deepest cells of the body.

– In these organisms, evolutionary adaptations

– consist of extensively branched or folded surfaces, which

increase the area of these surfaces and

– provide for sufficient environmental exchange.



The respiratory system exchanges gases between

the external environment and blood.

The digestive system acquires food and eliminates

wastes.

The excretory system eliminates metabolic waste.

The circulatory system

– distributes gases, nutrients, and wastes throughout the

body and

– exchanges materials between blood and body cells

through the interstitial fluid that bathes body cells.


Figure 20.13A EXTERNAL ENVIRONMENT

Mouth Food

CO2 O2

ANIMAL

Digestive system

Respiratory system

Circulatory system

Urinary system

Heart Interstitial fluid

Body cells

Intestine

Anus

Unabsorbed matter (feces)

Metabolic waste products (urine)

Nutrients

Homeostasis is the active maintenance of a

steady state within the body.

– External environmental conditions may fluctuate wildly.

– Homeostatic mechanisms regulate internal conditions.

20.14 Animals regulate their internal environment


Figure 20.14

Homeostatic mechanisms

External environment

Large fluctuations

Internal environment

Small fluctuations

Control systems

– detect change and

– direct responses.

Negative-feedback mechanisms

– keep internal variables steady and

– permit only small fluctuations around set points.

20.15 Homeostasis depends on negative feedback


Animation: Negative Feedback

Animation: Positive Feedback

20_15NegativeFeedback_A.html

20_15PositiveFeedback_A.html

Figure 20.15_s1

Homeostasis: Body temperature

approximately 37°C

Figure 20.15_s2

Brain activates cooling mechanisms.

Brain activates warming mechanisms.

Temperature rises above set point

Temperature falls below set point


approximately 37°C

Figure 20.15_s3 Sweat evaporates, cooling the body.

Blood vessels dilate.


Blood vessels constrict.

Brain activates warming mechanisms. Shivering generates

heat.




approximately 37°C

Figure 20.15_s4 Sweat evaporates, cooling the body.

Blood vessels dilate.


Cooling mechanisms shut off.

Warming mechanisms shut off.

Blood vessels constrict.

Brain activates warming mechanisms. Shivering generates

heat.

Temperature decreases

Temperature increases




approximately 37°C

Figure 20.15_5


approximately 37°C

Temperature decreases


The thermostat shuts off the cooling mechanisms.

Blood vessels in the skin dilate, increasing heat loss.

Sweat glands secrete sweat that evaporates, cooling the body. The thermostat

in the brain activates cooling mechanisms.

Figure 20.15_6


approximately 37°C

Temperature increases


The thermostat shuts off the warming mechanisms.

Blood vessels in the skin constrict, minimizing heat loss.

Skeletal muscles contract; shivering generates heat.

The thermostat in the brain activates warming mechanisms.

You should now be able to

1. Describe the levels of organization in an animal’s

body.

2. Explain how size and shape can influence the

structure of an animal.

3. Define a tissue, describe the four main types of

animal tissue, and note their structures and their

functions.

4. Explain how the structure of organs is based on

the cooperative interactions of tissues.


5. Explain how artificial tissues are created and

used.

6. Describe the general structures and functions of

the 12 major vertebrate organ systems.

7. Describe and compare X-ray, CT, MRI, and PET

imaging technologies.

8. Relate the structure of the skin to its functions.



9. Describe the systems that help an animal

exchange materials with its environment.

10. Describe examples of adaptations to increase

the surface-to-volume ratio.

11. Define the concept of homeostasis and illustrate

it with examples.

12. Explain how negative feedback is used to

regulate internal body temperature.



Figure 20.UN01

20.4 Epithelial tissue

covers the body and

lines its organs and

cavities.

20.5 Connective

tissue binds and

supports other

tissues.

20.6 Muscle

tissue functions

in movement.

20.7 Nervous tissue

forms a

communication

network.

Sheets of closely

packed cells

Sparse cells in extra-

cellular matrix

Long cells (fibers)

with contractile

proteins

Neurons with

branching extensions;

supporting cells

Columnar epithelium Loose connective tissue Skeletal muscle Neuron

Ex

am

ple

S

tru

ctu

re

Fu

nc

tio

n

Figure 20.UN01_1

20.4 Epithelial tissue

covers the body and

lines its organs and

cavities.

20.5 Connective

tissue binds and

supports other

tissues.

Sheets of closely

packed cells

Sparse cells in extra-

cellular matrix

Columnar epithelium Loose connective tissue

Ex

am

ple

S

tru

ctu

re

Fu

nc

tio

n

Figure 20.UN01_2

Ex

am

ple

S

tru

ctu

re

Fu

nc

tio

n

20.6 Muscle

tissue functions

in movement.

20.7 Nervous tissue

forms a

communication

network.

Long cells (fibers)

with contractile

proteins

Neurons with

branching extensions;

supporting cells

Skeletal muscle Neuron

Figure 20.UN02

a.

b.

c.

d. e.

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Chapter 20 Unifying Concepts of Animal Structure and …€¦ · © 2012 Pearson Education, Inc. Lecture by Edward J. Zalisko PowerPoint Lectures for Campbell Biology: Concepts &