© 2013 Pearson Education, Inc. Overview of Anatomy and Physiology Anatomy –Study of structure...

© 2013 Pearson Education, Inc.

Overview of Anatomy and Physiology

• Anatomy– Study of structure

• Subdivisions:– Gross or macroscopic (e.g., regional,

systemic, and surface anatomy)– Microscopic (e.g., cytology and histology)– Developmental (e.g., embryology)



• To study anatomy– Mastery of anatomical terminology– Observation– Manipulation– Palpation – Auscultation



• Physiology– Study of the function of the body– Subdivisions based on organ systems

(e.g., renal or cardiovascular physiology)– Often focuses on cellular and molecular level

• Body's abilities depend on chemical reactions in individual cells



• To study physiology– Ability to focus at many levels (from systemic

to cellular and molecular)– Study of basic physical principles (e.g.,

electrical currents, pressure, and movement) – Study of basic chemical principles


Principle of Complementarity

• Anatomy and physiology are inseparable– Function always reflects structure– What a structure can do depends on its

specific form

– FORM FIT FUNCTION


Levels of Structural Organization

• Chemical– Atoms and molecules (chapter 2); and organelles (chapter 3)

• Cellular– Cells (chapter 3)

• Tissue– Groups of similar cells (chapter 4)

• Organ– Contains two or more types of tissues

• Organ System– Organs that work closely together

• Organismal– All organ systems


Figure 1.1 Levels of structural organization. Slide 1

Atoms Molecule OrganelleSmooth muscle cell

Chemical levelAtoms combine toform molecules.

Cellular level Cells are made upof molecules.

Smooth muscle tissue

Cardiovascular system

HeartBloodvessels

Tissue levelTissues consist ofsimilar types of cells.

Blood vessel (organ)


Connective tissue

Epithelialtissue

Organ levelOrgans are made up of different typesof tissues.

Organismal levelThe human organism is madeup of many organ systems.

Organ system level Organ systems consist of differentorgans that work together closely.



Atoms Molecule











Connective tissue

Epithelialtissue









HeartBloodvessels




Connective tissue



Epithelialtissue








HeartBloodvessels




Connective tissue


Organismal levelThe human organism is madeup of many organ systems.


Epithelialtissue


Necessary Life Functions

• Maintaining boundaries

• Movement

• Responsiveness

• Digestion

• Metabolism

• Dispose of wastes

• Reproduction

• Growth

Will see examples starting in Next slide of all of these



• Maintaining boundaries between internal and external environments– Plasma membranes – Skin

• Movement (contractility)– Of body parts (skeletal muscle)– Of substances (cardiac and smooth muscle)



• Responsiveness– Ability to sense and respond to stimuli– Withdrawal reflex – Control of breathing rate

• Digestion– Breakdown of ingested foodstuffs– Absorption of simple molecules into blood



• Metabolism– All chemical reactions that occur in body cells– Catabolism and anabolism

• Excretion– Removal of wastes from metabolism and

digestion– Urea, carbon dioxide, feces



• Reproduction – Cellular division for growth or repair– Production of offspring

• Growth– Increase in size of a body part or of organism


Interdependence of Body Cells

• Humans are multicellular– To function, must keep individual cells alive– All cells depend on organ systems to meet

their survival needs

• All body functions spread among different organ systems

• Organ systems cooperate to maintain life– Note major organs and functions of the 11

organ systems (fig. 1.3)


Figure 1.2 Examples of interrelationships among body organ systems.

Digestive system Takes in nutrients, breaks them down, and eliminates unabsorbed matter (feces)

Food O2 CO2

Respiratory systemTakes in oxygen and eliminates carbon dioxide

Cardiovascular systemVia the blood, distributes oxygen and nutrients to all body cells and delivers wastes and carbon dioxide to disposal organs

BloodCO2

O2

Heart

Nutrients

Interstitial fluid

Integumentary system Protects the body as a whole from the external environment

Nutrients and wastes pass between blood and cells via the interstitial fluid

Feces Urine

Urinary system Eliminates nitrogenouswastes andexcess ions


Figure 1.3a The body’s organ systems and their major functions.

Hair

Skin Nails

Integumentary SystemForms the external body covering,and protects deeper tissues from injury.Synthesizes vitamin D, and housescutaneous (pain, pressure, etc.)receptors and sweat and oil glands.


Figure 1.3b The body’s organ systems and their major functions.

Joint

Bones

Skeletal SystemProtects and supports body organs, and provides a framework the muscles use to cause movement. Blood cells are formed within bones. Bones store minerals.


Figure 1.3c The body’s organ systems and their major functions.

Skeletalmuscles

(c) Muscular SystemAllows manipulation of the environment,locomotion, and facial expression.Maintains posture, and produces heat.


Figure 1.3d The body’s organ systems and their major functions.

Brain

NervesSpinalcord

Nervous SystemAs the fast-acting control system ofthe body, it responds to internal andexternal changes by activatingappropriate muscles and glands.


Figure 1.3e The body’s organ systems and their major functions.

Endocrine SystemGlands secrete hormones thatregulate processes such as growth,reproduction, and nutrient use(metabolism) by body cells.

Pineal gland

Pituitarygland

Testis

Thyroidgland

Thymus

Adrenalgland

Pancreas

Ovary


Figure 1.3f The body’s organ systems and their major functions.

Cardiovascular SystemBlood vessels transport blood,which carries oxygen, carbon dioxide,nutrients, wastes, etc. The heartpumps blood.

Heart

Bloodvessels


Figure 1.3g The body’s organ systems and their major functions.

Lymphatic System/ImmunityPicks up fluid leaked from blood vesselsand returns it to blood. Disposesof debris in the lymphatic stream.Houses white blood cells (lymphocytes)involved in immunity. The immuneresponse mounts the attack againstforeign substances within the body.

Lymph nodes

Spleen

Thoracicduct

Lymphaticvessels

Thymus

Red bonemarrow


Figure 1.3h The body’s organ systems and their major functions.

Respiratory SystemKeeps blood constantly supplied withoxygen and removes carbon dioxide.The gaseous exchanges occur throughthe walls of the air sacs of the lungs.

Lung

Trachea

Larynx

Pharynx

Nasalcavity

Bronchus


Figure 1.3i The body’s organ systems and their major functions.

Oral cavity

Esophagus

Liver

StomachSmallIntestine

LargeIntestine

Rectum

Anus

Digestive SystemBreaks down food into absorbable unitsthat enter the blood for distribution tobody cells. Indigestible foodstuffs areeliminated as feces.


Kidney

Ureter

Urinarybladder

Urethra

Urinary SystemEliminates nitrogenous wastes from thebody. Regulates water, electrolyte andacid-base balance of the blood.

Figure 1.3j The body’s organ systems and their major functions.


Prostategland

Penis

Testis

Scrotum

Ductusdeferens

Male Reproductive SystemOverall function is production of offspring. Testesproduce sperm and male sex hormone, and maleducts and glands aid in delivery of sperm to thefemale reproductive tract. Ovaries produce eggsand female sex hormones. The remaining femalestructures serve as sites for fertilization anddevelopment of the fetus. Mammary glands offemale breasts produce milk to nourish the newborn.

Uterus

Vagina

Uterinetube

Ovary

Mammaryglands (inbreasts)

Female Reproductive SystemOverall function is production of offspring. Testesproduce sperm and male sex hormone, and maleducts and glands aid in delivery of sperm to thefemale reproductive tract. Ovaries produce eggsand female sex hormones. The remaining femalestructures serve as sites for fertilization anddevelopment of the fetus. Mammary glands of femalebreasts produce milk to nourish the newborn.

Figure 1.3k–l The body’s organ systems and their major functions.


Survival Needs

• Appropriate amounts necessary for life– Too little or too much harmful

• Nutrients

• Oxygen

• Water

• Normal body temperature

• Appropriate atmospheric pressure


Survival Needs

• Nutrients– Chemicals for energy and cell building– Carbohydrates, fats, proteins, minerals,

vitamins

• Oxygen– Essential for energy release (ATP production)


Survival Needs

• Water– Most abundant chemical in body– Environment of chemical reactions– Fluid base for secretions and excretions

• Normal body temperature– 37° C– Affects rate of chemical reactions

• Appropriate atmospheric pressure– For adequate breathing and gas exchange in

lungs


Homeostasis

• Homeostasis– Maintenance of relatively stable internal

conditions despite continuous changes in environment

– A dynamic state of equilibrium– Maintained by contributions of all organ

systems


Homeostatic Control Mechanisms

• Involve continuous monitoring and regulation of all factors that can change (variables)

• Communication necessary for monitoring and regulation – Functions of nervous and endocrine systems

• Nervous and endocrine systems accomplish communication via nerve impulses and hormones


Components of a Control Mechanism

• Receptor (sensor)– Monitors environment– Responds to stimuli (something that causes changes in

controlled variables)

• Control center– Determines set point at which variable is maintained– Receives input from receptor– Determines appropriate response

• Effector– Receives output from control center– Provides the means to respond – Response either reduces (negative feedback) or enhances

stimulus (positive feedback)


Figure 1.4 Interactions among the elements of a homeostatic control system maintainstable internal conditions.

Slide 1

Output: Information sentalong efferent pathway toeffector.

Input: Informationsent along afferentpathway to controlcenter.

3

Receptordetectschange.

2

Stimulus produceschange invariable.

1

4

Responseof effectorfeeds back toreduce theeffect ofstimulus andreturnsvariableto homeostatic level.

5

ControlCenter

Afferentpathway

Efferentpathway

Receptor Effector

BALANCE

IMBALANCE

IMBALANCE



Slide 2


1

BALANCE

IMBALANCE

IMBALANCE



Slide 3


1


2

BALANCE

IMBALANCE

IMBALANCE

Receptor



Slide 4

Afferentpathway


1


2


3

BALANCE

IMBALANCE

IMBALANCE

Receptor

ControlCenter



Slide 5

Afferentpathway

Efferentpathway


1


2


3

BALANCE

IMBALANCE

IMBALANCE

Receptor

ControlCenter

Effector


4



Slide 6

Afferentpathway

Efferentpathway


1


2


3

BALANCE

IMBALANCE

IMBALANCE

Receptor

ControlCenter

Effector


4

Responseof effectorfeeds back toreduce theeffect ofstimulus andreturnsvariableto homeostatic level.

5


Negative Feedback

• Most feedback mechanisms in body

• Response reduces or shuts off original stimulus– Variable changes in opposite direction of

initial change

• Examples– Regulation of body temperature (a nervous

system mechanism)– Regulation of blood volume by ADH (an

endocrine system mechanism)


Figure 1.5 Body temperature is regulated by a negative feedback mechanism.

Control Center(thermoregulatory

center in brain)

Afferentpathway

Efferentpathway

ReceptorsTemperature-sensitivecells in skin and brain)

EffectorsSweet glands

Sweat glands activated

ResponseEvaporation of sweatBody temperature falls;stimulus ends

Body temperaturerises

Stimulus: Heat

ResponseBody temperature rises;stimulus ends

EffectorsSkeletal muscles

EfferentpathwayShivering begins

BALANCE

IMBALANCE

IMBALANCE

Afferentpathway

Control Center(thermoregulatory

center in brain)

ReceptorsTemperature-sensitivecells in skin and brain

Stimulus: Cold

Body temperaturefalls


Negative Feedback: Regulation of Blood Volume by ADH

• Receptors sense decreased blood volume

• Control center in hypothalamus stimulates pituitary gland to release antidiuretic hormone (ADH)

• ADH causes kidneys (effectors) to return more water to the blood


Positive Feedback

• Response enhances or exaggerates original stimulus

• May exhibit a cascade or amplifying effect

• Usually controls infrequent events that do not require continuous adjustment– Enhancement of labor contractions by

oxytocin (chapter 28)– Platelet plug formation and blood clotting


Figure 1.6 A positive feedback mechanism regulates formation of a platelet plug.Slide 1

Releasedchemicalsattract moreplatelets.

Positivefeedbackloop

Plateletsadhere to site andrelease chemicals.

Feedback cycle endswhen plug is formed.

Platelet plugis fully formed.

Break or tearoccurs in bloodvessel wall.

Positive feedback cycle is initiated.

1

23

4





1





1


2






1


2 Releasedchemicalsattract moreplatelets.

3




Feedback cycle endswhen plug is formed.



1


2

Platelet plugis fully formed.4

Releasedchemicalsattract moreplatelets.

3


Homeostatic Imbalance

• Disturbance of homeostasis– Increases risk of disease– Contributes to changes associated with aging

• Control systems less efficient

– If negative feedback mechanisms overwhelmed

• Destructive positive feedback mechanisms may take over (e.g., heart failure)

© 2013 Pearson Education, Inc. Overview of Anatomy and Physiology Anatomy –Study of structure...

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