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Human BodyHuman Body

Bones, Muscles and SkinBones, Muscles and Skin

Chapter 14-1Chapter 14-1

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Body Organization and Body Organization and HomeostasisHomeostasis

Key Concepts:Key Concepts:• What are the levels of organization in What are the levels of organization in

the bodythe body• What is homeostasis What is homeostasis

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VocabularyVocabulary

CellCell Cell Cell MembraneMembrane

NucleusNucleus

CytoplasmCytoplasm TissueTissue Muscle TissueMuscle Tissue

Nervous Nervous TissueTissue

Connective Connective TissueTissue

Epithelial Epithelial tissuetissue

OrganOrgan Organ SystemOrgan System HomeostasisHomeostasis

StressStress

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Lunch in the cafeteriaLunch in the cafeteria The bell rings you hurry down the hall to The bell rings you hurry down the hall to

the cafeteriathe cafeteria You smell hot pizza, and nachos this You smell hot pizza, and nachos this

makes your mouth watermakes your mouth water You get your food and balance your tray You get your food and balance your tray After you pay you look around for your After you pay you look around for your

friendsfriends You walk over, sit down, and eatYou walk over, sit down, and eat Think about how many body parts were Think about how many body parts were

involved in this simple act of getting and involved in this simple act of getting and eating your luncheating your lunch

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OrganizationOrganization

The levels of organization in the The levels of organization in the human body consist of cells, tissues, human body consist of cells, tissues, organs and organ systemsorgans and organ systems

Smallest unit of organization-CELLSmallest unit of organization-CELL Next largest unit-TISSUE, then Next largest unit-TISSUE, then

OrgansOrgans Largest unit of organization-ORGAN Largest unit of organization-ORGAN

SYSTEMSYSTEM

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CellsCells

Basic unit of structure and function in Basic unit of structure and function in a living thing is a cella living thing is a cell

The structure of most animal The structure of most animal cells/including the human body are cells/including the human body are cell membrane, nucleus and cell membrane, nucleus and cytoplasmcytoplasm

The human body is made up of The human body is made up of trillions of tiny cellstrillions of tiny cells

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Function of CellsFunction of Cells

Cells carry on the processes that Cells carry on the processes that keep organisms alivekeep organisms alive• They release energy for the bodies They release energy for the bodies

activitiesactivities• Grow and reproduceGrow and reproduce• They get rid of waste products that They get rid of waste products that

result from these activitiesresult from these activities

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TissuesTissues

Group of similar cells that perform Group of similar cells that perform the same functionthe same function

Four basic types of tissueFour basic types of tissue• MuscleMuscle• NervousNervous• ConnectiveConnective• Epithelial Epithelial

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Muscle tissueMuscle tissue

Every movement you make depends Every movement you make depends on muscle tissueon muscle tissue

Muscle tissue can contract Muscle tissue can contract

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Nervous tissueNervous tissue

Enables you to see, hear and thinkEnables you to see, hear and think Directs and controls, it carries Directs and controls, it carries

electrical messages back and forth electrical messages back and forth between the brain and other parts of between the brain and other parts of the bodythe body

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Connective TissueConnective Tissue

Connects and supports parts of your Connects and supports parts of your bodybody

Bone tissue and fat are connective Bone tissue and fat are connective tissuestissues

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Epithelial TissueEpithelial Tissue

Covers the surfaces of your body and Covers the surfaces of your body and lines your internal organslines your internal organs

Some epithelial tissue such as your Some epithelial tissue such as your skin protects the delicate structures skin protects the delicate structures that lie beneath itthat lie beneath it

Digestive system is lined with Digestive system is lined with epithelial tissue which allows you to epithelial tissue which allows you to digest and absorb the nutrients in digest and absorb the nutrients in your foodyour food

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Organs and Organ SystemsOrgans and Organ Systems

What is an example of an organ?What is an example of an organ?• Stomach, heart, brain lungsStomach, heart, brain lungs

• An organ is composed of different kinds An organ is composed of different kinds of tissue and performs a specific jobof tissue and performs a specific job

• Each organ is part of an organ system a Each organ is part of an organ system a group of organs that work together to group of organs that work together to perform a major functionperform a major function

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HomeostasisHomeostasis

When all the systems work together When all the systems work together such as respiratory, digestive and such as respiratory, digestive and circulatory they are maintaining a circulatory they are maintaining a process called homeostasisprocess called homeostasis

The process by which an organisms The process by which an organisms internal environment is kept stable in internal environment is kept stable in spite of changes in the external spite of changes in the external environmentenvironment

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Maintaining HomeostasisMaintaining Homeostasis

Your body has various ways of Your body has various ways of maintaining homeostasismaintaining homeostasis• When you are too warm you sweat When you are too warm you sweat

which helps to cool your bodywhich helps to cool your body• When you are cold you shiver-shivering When you are cold you shiver-shivering

occurs when your muscles contract and occurs when your muscles contract and relax rapidlyrelax rapidly

• These processes help maintain These processes help maintain homeostasishomeostasis