THE HUMAN BODY

Bellwork 11/8 Why does our body sweat

when we are hot or shiver when we are cold?

Maintaining Homeostasis

Shivering occurs when your muscles rapidly contract and relax.

Sweating helps to cool your body. Your internal body temperature will be close to 37 degrees C. If you become sick, you body temperature may rise but it will return to 37 degrees C when you are well again.

This action produces heat that helps keep you warm.

HomeostasisThe maintenance of a stable

internal environment in the body in spite of changes in the external environment

Constantly working to keep the body in balance

Outside factors make this hard

Stress and Homestasis

Stress- The reaction of your body to potentially threatening, challenging, or disturbing events

Your heart may beat more rapidly Your breathing may increase Your endocrine system might release a

chemical called adrenaline into your bloodstream

Adrenaline gives your body burst of energy and prepares your body to take action

Your muscles work harder and require more oxygen

Oxygen is carried to the circulatory system Your heart then beats faster so that more

oxygen can get into your body.

Body OrganizationCellsTissuesOrgansSystems

CellsBuilding blocks of lifeBody is composed of billions of

different cellsWhen cells of the same type

work together to do a job they form a TISSUE

Tissues

TissuesFour main types

EpithelialNervousMuscleConnective

Epithelial TissuesCover and protect underlying

tissueSkin for example

Nervous TissueSend messages through the

bodyFound in

Brain, nerves, and sensory organs

Muscle TissueMade of cells that contract and

relaxProduce movement

Connective TissueMany jobs

Joins/supports/insulatesKeeps organs from falling apartExamples

Bone and blood

OrgansTwo or more tissues working

together form an ORGANStomach uses all four types of

tissues to perform digestion

Body SystemsOrgans working together form

systems12 major systems in the bodySome organs are part of more

than one system at a time

The Skeletal System

Skeletal SystemMade of bones, cartilage and

the connective tissue that holds the bones together

206 in adultsMultiple Functions

Functions of Skeletal System

ProtectionStorageMovementBlood Cell Formation

ProtectionPrevents damage to organs

Skull protects brainRibcage protects heart, lungs,

etc…Spine protects spinal cord

StorageMinerals needed to help

nerves and muscles workLong bones can store fat for

energy

MovementAllow for places

for muscles to attach

Movement of skeletal muscles allow to move

Blood Cell FormationMarrow of

some bones make cells of the blood

Bone StructureMade of connective tissue and

mineralsMinerals deposited by cells

called osteoblastsTwo kinds of tissue

Compact bone and spongy bone

Bone StructureCompact Bone

Rigid and denseSpongy Bone

Many open spacesProvide strength and support of

bone

Bone StructureBone Marrow

Soft tissue inside boneRed marrow produces red and

white blood cellsYellow marrow stores fat

Bone GrowthBones start as cartilage and

harden as you get olderTips of ears and nose the

cartilage never gets hard

JointsPlace where two or more bones

meetTwo major types of joints

Immovable Movable

Immovable JointsLittle or no movement is

allowedBones of skull are held

together this way

Immovable Joints

Movable JointsHeld together by connective

tissue called ligamentsThree Main Types

Gliding JointBall-and-Socket JointHinge Joint

Movable JointsCartilage

Protective covering over ends of bones

Keeps bones from rubbing together

Gliding JointAllow bones to move past one

anotherFound in hand and wrist

Ball-and-Socket JointAllows for movement in many

different directionsRotate at this joint

ShoulderHip

Hinge JointOpen and close like a doorKneeElbow

Muscular System

The Muscular SystemMade up of all the muscles

that let you moveTwo Main Types

InvoluntaryVoluntary

Involuntary MusclesMuscles that you do not have

to think about to controlAct on their own Important for:

Breathing, heart beating, blinking, etc…

Voluntary MusclesMuscles that you control with

thoughtMovements

Smiling, speaking, raising your hand, walking, etc…

Muscle TissueThree Types of Muscle Tissue

Smooth MuscleSkeletal Muscle Cardiac Muscle

Smooth Muscle Tissue Involuntary Muscle

Makes up the inside of many organs

Act without thoughtExample: digestion in the

stomach is automatic

Smooth Muscle

Skeletal Muscle TissueVoluntary Muscles

Attached to bones by tendonsResponsible for movingCalled striated muscles

Appear bandedWith lots of use become tired

(fatigued)

Skeletal Muscle Tissue

Cardiac MuscleFound only in heart Is involuntary like smoothStriated like skeletal

Unlike skeletal it never gets tired

Cardiac Muscle Tissue

Muscles at WorkFunction by contractingMessage from nervous systemWork in pairs

When one muscle contracts its mate relaxes to its original length

Muscles at Work

Muscles at Work

Muscles at Work

Strength and FlexibilitySome muscles can be made

stronger and made to last longerRegular exercise can helpResistance and Aerobic

Exercise

Integumentary System

Integumentary SystemMade up of skin, hair, and

nailsCovers the body and helps

maintain homeostasisSkin is largest organ in body

Functions of SkinProtecting the BodyMaintaining TemperatureEliminating WastesGathering InformationProducing Vitamin D

Protecting the BodyForms a barrier

Keeps disease-causing microorganisms out

Keeps important substances inside bodyPrevents you from drying out

Maintaining TemperatureBlood vessels in skin will

enlarge when you get hotAllows more blood to area and a

temperature drop to occurSweat glands produce

perspiration

Eliminating WastesSweat contains waste

materialsKeeps some harmful materials

from building up in your bodyThis is why sweat is salty

Gathering InformationLots of nerve endings in skin

As you touch things your body collects informationPressure/pain/temperature

Keeps you safe

Producing Vitamin D In presence of sunlight

Important for healthy bonesHelps cells to absorb calcium

in foodOnly need a few minutes of

sunlight each day

Layers of the SkinTwo Main Layers

Epidermis

Dermis

Layers of the Skin

The EpidermisOuter layerThinner than dermisNo nerves or blood vesselsCells of epidermis (epithelial)

are replaced about every 4 weeks

The EpidermisOuter layer is dead cells

This is what protects and cushions

Shedding of dead cells carries away bacteria

Melanin is produced in epidermis

The EpidermisMelanin protects skin by

creating a tan when exposed to sun light

Also cells in epidermis that produce fingernails

The Dermis Inner layer of skinHas:

Nerves/Blood Vessels/Sweat Glands/Hairs/Oil Glands

Sweat and oil reach surface through pores

The DermisHair grow from follicles

Hair you see is made of dead cells

Oil produced helps make hair waterproof and keep skin moist

Injuries, Disorders, and Diseases of the Skeletal

System Fractures Postural Deformities Arthritis Cancer Osteoporosis Rickets

Fractures A fracture is any break in the bone About 6 different types

We will cover 3 Simple Greenstick Compound

Simple Fractures A clean break of the bone

Bone is often split into two pieces

No damage to skinMay result in bruising

Simple Fracture

Greenstick Fracture Bone is not completely broken

One side shows break Other just bends

Most commonly seen in children Due to pliable nature of young

bones

Greenstick Fracture

Compound Fracture Also known as an “Open” fracture Broken end of bone pushes out

and breaks through skin Can result in damage to tissues

and infection

Compound Fracture

Arthritis Inflammation of one or more joints Causes range depending on type of

arthritis Osteo arthritis is caused by wearing

away of cartilage Rheumatoid arthritis is caused when

body attacks and breaks down cartilage (autoimmune disorder)

Rheumatoid Arthritis

Injuries, Diseases and Disorders of the Muscular System

Sprains Strains Dystrophy

Sprains and Strains A sprain is when a ligament gets

stretched too far Symptoms of a sprain are: pain, swelling, and

bruising of the affected joint A strain is an injury to a muscle or tendon,

usually occurring when stretched too far Can lead to muscle tears when a rip occurs in

the muscle or tendon

Muscle Tear

Dystrophy Refers to a group of diseases All result in a wasting of the

muscles Loss of control May extend to internal organs

Leading to problems with organs functioning or even death

Injuries, Disorders, Diseases of Skin

Hundreds of different problems can occur with the skin and underlying connective tissue

Will look at just twoAcnePsoriasis

Acne Term for pimples on the skin At puberty the oil glands of the

skin start producing an oily material (sebum) Sometimes the wall of the oil gland

breaks and spills the sebum within the skin which causes redness, swelling, and pus (a pimple)

Acne

Psoriasis Causes are unknown Runs in families Results in areas of the skin

growing much faster than others Creates red and scaly patches that

itch

Psoriasis

Can Happen On the Nails as Well