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Chapter 1:

The Human Body:

An Orientation

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Anatomy & Physiology

• Anatomy = Structure

• Physiology = Function

• Complementarity of structure and function

The hand grasps objects The mouth receives food 2

Levels of Structural Organization

Cardiovascular

system

Organelle Molecule Atoms

Chemical level

Cellular level

Tissue level

Organ level

Organ system level Organismal level

Smooth muscle cell

Smooth muscle tissue

Blood vessel (organ)

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The 11 Organ Systems

• Integumentary

• Skeletal

• Muscular

• Nervous

• Endocrine

• Cardiovascular

• Lymphatic

• Respiratory

• Digestive

• Urinary

• Reproductive

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The Organ Systems

Bones

Joint

Nails Skin

Hair

Skeletal

muscles

Skeletal System Integumentary System Muscular System

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The Organ Systems

Brain

Sensory

receptor

Nerves Spinal

cord

Thyroid

gland

Thymus

Adrenal

gland

Pancreas

Testis

Ovary

Heart

Blood

vessels

Nervous System Endocrine System Cardiovascular System

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The Organ Systems

Lymphatic System Respiratory System

Lymphatic

vessels

Red bone

marrow

Thoracic

duct

Thymus

Spleen

Lymph

nodes

Nasal

cavity

Bronchus Pharynx

Larynx

Trachea

Lung Liver

Oral cavity

Esophagus

Large

intestine

Stomach

Small

intestine

Rectum

Anus

Digestive System

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The Organ Systems

Kidney

Ureter

Urinary

bladder

Urethra

Prostate

gland

Ductus

deferens

Penis

Testis Scrotum

Ovary

Uterine

tube

Mammary

glands (in

breasts)

Uterus

Vagina

Urinary System Male Reproductive Female Reproductive

System System

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Maintaining Life

• Organ systems have

to be interrelated

and synergistic in

order to maintain

life!

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Maintaining Life: Necessary Life

Functions

• Maintaining Boundaries

• Movement

• Responsiveness

• Digestion

• Metabolism

• Excretion

• Reproduction

• Growth

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Necessary Life Functions:

Maintaining Boundaries

• Distinct internal environment

from surrounding external

environment

• Encloses contents & essential

substances

• Protective nature:

– Heat/ Dehydration

– Cold

– Toxins

– Pathogens 11

Necessary Life Functions:

Movement

• Movement is necessary on all

levels of organization!

• Change in position of the body,

body parts, or motion of

internal organs

• Ability to manipulate external

environment

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Necessary Life Functions:

Responsiveness

• Ability to sense stimuli and

respond to them

• May be conscious or

unconscious/ reflexes

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Necessary Life Functions:

Digestion

• Breaking down ingested food

into simple nutrient molecules

that the body can absorb

• May be physical or chemical in

nature

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Necessary Life Functions:

Metabolism

• All chemical reactions that

occur within the body

• Catabolism

– Breaking down substances

into their basic form

• Anabolism

– Synthesizing larger

molecules from basic units

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Necessary Life Functions:

Excretion

• Removal of waste products

produced by metabolic

reactions

• Waste products are either non-

usable by-products, or

potential toxins

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Necessary Life Functions:

Reproduction

• Occurs at the cellular &

organismal levels

• Cells divide to produce two

identical cells necessary for

growth & repair

• Organisms produce offspring

and as a result, pass on

genetic information

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Necessary Life Functions:

Growth

• Increase in body size without

change in shape

• Accomplished by:

– Increased cell number

– Increased cell size

• Occurs when “construction”

out-paces “destruction

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Requirements for Life:

Survival Needs

• Nutrients

• Oxygen

• Water

• Heat

• Atmospheric Pressure

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Requirements for Life:

Survival Needs

• Nutrients:

– Used as energy source

– Supply raw material for building new living matter

– Help regulate vital chemical reactions

• Oxygen:

– Is used to release energy from food substances

– Released energy then drives metabolic

processes

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Requirements for Life:

Survival Needs

• Water:

– Most abundant chemical in the body

– Required for metabolic processes

– Transports substances throughout the body

– Important for regulating body temperature

• Heat:

– Excessively below normal body temperature, metabolism

slows down and eventually comes to a stop

– Excessively above normal body temperature, metabolism

is too rapid, proteins & enzymes denature

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Requirements for Life:

Survival Needs

• Atmospheric Pressure:

– Force air exerts on the surface of the body

– Affects breathing rate and gas exchange &

ultimately, cellular metabolism

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