Chapter 1: The Human Body: An Orientation

Anatomy & Physiology

• Anatomy = Structure

• Physiology = Function

• Complementarity of structure and function

The hand grasps objects The mouth receives food

Levels of Structural Organization

Cardiovascularsystem

OrganelleMoleculeAtoms

Chemical level Cellular level

Tissue level

Organ level

Organ system levelOrganismal level

Smooth muscle cell

Smooth muscle tissue

Blood vessel (organ)

The 11 Organ Systems

• Integumentary

• Skeletal

• Muscular

• Nervous

• Endocrine

• Cardiovascular

• Lymphatic

• Respiratory

• Digestive

• Urinary

• Reproductive

The Organ Systems

Bones

Joint

NailsSkin

HairSkeletalmuscles

Skeletal SystemIntegumentary System Muscular System

The Organ Systems

Brain

Sensoryreceptor

NervesSpinalcord

Thyroidgland

Thymus

Adrenalgland

Pancreas

Testis

Ovary

Heart

Bloodvessels

Nervous System Endocrine System Cardiovascular System

The Organ Systems

Lymphatic System Respiratory System

Lymphaticvessels

Red bonemarrow

Thoracicduct

Thymus

Spleen

Lymph nodes

Nasalcavity

BronchusPharynxLarynxTrachea

LungLiver

Oral cavity

Esophagus

Largeintestine

Stomach

Smallintestine

RectumAnus

Digestive System

The Organ Systems

Kidney

Ureter

Urinarybladder

Urethra

Prostategland

Ductusdeferens

Penis

TestisScrotum

Ovary

Uterinetube

Mammaryglands (inbreasts)

Uterus

Vagina

Urinary System Male Reproductive Female Reproductive System System

Maintaining Life

• Organ systems have to be interrelated and synergistic in order to maintain life!

Maintaining Life: Necessary Life Functions

• Maintaining Boundaries• Movement• Responsiveness• Digestion• Metabolism• Excretion• Reproduction• Growth

Necessary Life Functions: Maintaining Boundaries

• Distinct internal environment from surrounding external environment

• Encloses contents & essential substances

• Protective nature:– Heat/ Dehydration– Cold– Toxins– Pathogens

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

Necessary Life Functions: Responsiveness

• Ability to sense stimuli and respond to them

• May be conscious or unconscious/ reflexes

Necessary Life Functions: Digestion

• Breaking down ingested food into simple nutrient molecules that the body can absorb

• May be physical or chemical in nature

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

Necessary Life Functions: Excretion

• Removal of waste products produced by metabolic reactions

• Waste products are either non-usable by-products, or potential toxins

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

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

Requirements for Life: Survival Needs

• Nutrients

• Oxygen

• Water

• Heat

• Atmospheric Pressure

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

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

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