the human body: an orientation ch . 1a

Copyright © 2010 Pearson Education, Inc.

THE HUMAN BODY: AN ORIENTATION CH. 1A


Overview of Anatomy and Physiology

• Anatomy:

• Physiology:


Principle of Complementarity

• Anatomy and physiology are inseparable.


Levels of Structural Organization

• Chemical:

• Cellular:

• Tissue:

• Organ:

• Organ system:

• Organismal:


Cardiovascularsystem

OrganelleMoleculeAtoms

Chemical level Cellular level

Tissue levelTissues consist of similartypes of cells.

Organ levelOrgans are made up of different typesof tissues.

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

Organismal levelThe human organism is made upof many organ systems.

Smooth muscle cell

Smooth muscle tissue

Connective tissue

Blood vessel (organ)

HeartBloodvessels

Epithelialtissue

Smooth muscle tissue

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3

4

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Figure 1.1

Copyright © 2010 Pearson Education, Inc. Figure 1.3a

NailsSkin

Hair

Integumentary System – Maintains boundaries:1. Cellular Membranes2. Skin

Copyright © 2010 Pearson Education, Inc. Figure 1.3b

Bones

Joint

Skeletal System –• Movement •Protects and supports body organs•Attachment site for muscles•Mineral storage•Blood cell formation

Copyright © 2010 Pearson Education, Inc. Figure 1.3c

Skeletalmuscles

Muscular System• Locomotion, facial expression•Maintains posture•Produces heat.

Copyright © 2010 Pearson Education, Inc. Figure 1.3d

Brain

NervesSpinalcord

Nervous System• Fast-acting control system of the body•Responds to internal & external changes by activating appropriate muscles and glands.

Copyright © 2010 Pearson Education, Inc. Figure 1.3e

Pineal gland

PituitaryglandThyroid

glandThymus

AdrenalglandPancreas

Testis

Ovary

Endocrine System• Glands secrete hormones that regulate processes various processes

Copyright © 2010 Pearson Education, Inc. Figure 1.3f

Cardiovascular System• Blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes, etc. The heart pumps blood.

Heart

Bloodvessels

Copyright © 2010 Pearson Education, Inc. Figure 1.3g

Lymphaticvessels

Red bonemarrow

Thoracicduct

Thymus

Spleen

Lymphnodes

(Lymphatic System/Immunity• Picks up fluid leaked from blood vessels and returns it to blood•Disposes of debris in lymphatic stream• Houses WBC’s involved in immunity.

Copyright © 2010 Pearson Education, Inc. Figure 1.3h

Nasalcavity

Bronchus

Pharynx

Larynx

Trachea

Lung

Respiratory System• Keeps blood constantly supplied with oxygen and removes carbon dioxide.

Copyright © 2010 Pearson Education, Inc. Figure 1.3i

Liver

Oral cavity

Esophagus

Largeintestine

StomachSmallintestine

RectumAnus

Digestive System• Breaks down food into absorbable units that enter blood for distribution to body cells. Indigestible foodstuffs are eliminated as feces.

Copyright © 2010 Pearson Education, Inc. Figure 1.3j

Kidney

Ureter

UrinarybladderUrethra

Urinary System•Eliminates nitrogenous wastes •Regulates water, electrolyte and acid-base balance of the blood.

Copyright © 2010 Pearson Education, Inc. Figure 1.3k-l

Prostategland

Ductusdeferens

Penis

Testis

Scrotum

Ovary

Uterinetube

Mammaryglands (inbreasts)

Uterus

Vagina

Overall function is production of offspring.

Male Reproductive System (Female Reproductive System

Copyright © 2010 Pearson Education, Inc. Figure 1.3

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

Respiratory systemTakes in oxygen and eliminates carbon dioxide

Food O2 CO2

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

Interstitial fluid

Nutrients

Urinary systemEliminates nitrogenouswastes andexcess ions

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

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

Blood

Heart

Feces Urine

CO2

O2


Survival Needs

1. Nutrients

2. Oxygen

3. Water

4. Normal body temperature

5. Appropriate atmospheric pressure


Homeostasis

• Definition:

• A dynamic state of equilibrium


Components of a Homeostatic Control Mechanism

1. Receptor (sensor)

2. Control center

3. Effector


Stimulusproduceschange invariable.

Receptordetectschange.

Input: Informationsent along afferentpathway to controlcenter.

Output:Information sent alongefferent pathway toeffector.

Responseof effectorfeeds backto reducethe effect ofstimulusand returnsvariable tohomeostaticlevel.

Receptor Effector

ControlCenter

BALANCE

Afferentpathway

Efferentpathway

IMBALANCE

IMBALANCE

1

2

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5

Figure 1.4


Negative Feedback

• The response reduces or shuts off the original stimulus

• Example:

• Regulation of body temperature


Sweat glands activated

Shiveringbegins

StimulusBody temperaturerises BALANCE

Information sentalong the afferentpathway to controlcenter

Information sentalong the afferentpathway to controlcenter

Afferentpathway

Afferentpathway

Efferentpathway

Efferentpathway

Information sentalong the efferentpathway toeffectors

Information sentalong the efferentpathway to effectors

StimulusBody temperature falls

ReceptorsTemperature-sensitivecells in skin and brain

ReceptorsTemperature-sensitivecells in skin and brain

EffectorsSweat glands

EffectorsSkeletal muscles

Control Center(thermoregulatory

center in brain)

Control Center(thermoregulatory

center in brain)

ResponseEvaporation of sweatBody temperature falls;stimulus ends

ResponseBody temperature rises;stimulus ends


Positive Feedback

• The response enhances or exaggerates the original stimulus

• Rare in biological systems

• Example:

• Enhancement of labor contractions by oxytocin


Feedback cycle endswhen plug is formed.

Positive feedbackcycle is initiated.

Positivefeedbackloop

Break or tearoccurs in bloodvessel wall.

Plateletsadhere to siteand releasechemicals.

Releasedchemicalsattract moreplatelets.

Platelet plugforms.

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Figure 1.6


CHAPTER 1B


Anatomical Position

• Standard anatomical body position:

• Body erect

• Feet slightly apart

• Palms facing forward


Regional Terms

• Regional Terms: designate specific areas/regions of the body.


Cervical

(a) Anterior/Ventral

Pubic

OrbitalNasalOral

ThoracicAxillary

SternalAbdominalUmbilicalPelvicInguinal

Upper limbAcromialBrachial (arm)AntecubitalAntebrachial (forearm)Carpal (wrist)

Digital

Lower limbCoxal (hip)Femoral (thigh)PatellarCrural (leg)Fibular

Tarsal (ankle)ThoraxAbdomenBack (Dorsum)


Cervical Back (dorsal)

(b) Posterior/Dorsal

Scapular Vertebral Lumbar Sacral Gluteal

Upper limb AcromialBrachial (arm) Olecranal

Digital

Femoral (thigh) Popliteal Sural (calf) Fibular

Calcaneal Plantar

Cephalic

Occipital (back of head)


Body Planes and Sections

• Sagittal plane

• Midsagittal (median) plane

• Parasagittal plane

• Frontal (coronal) plane

• Transverse (horizontal) plane


Transverse plane

Median (midsagittal) plane

Frontal plane

Liver

Spleen

Pancreas

Aorta

Vertebralcolumn

Spinal cord

Subcutaneous fat layerBody wall

Rectum IntestinesLeft andright lungs

Liver HeartStomach

SpleenArm

(a) Frontal section (through torso)

(b) Transverse section (through torso, inferior view)

(c) Median section (midsagittal)


Body Cavities

• Two Large Cavities:

• Dorsal cavity

• Two subdivisions:

• Cranial cavity

• Vertebral cavity


Body Cavities

• Ventral cavity

• Two subdivisions (separated by diaphragm):


Cranialcavity

Dorsalbodycavity

Vertebralcavity

Cranialcavity

Vertebralcavity

Abdomino-pelviccavity

Ventral bodycavity(thoracic andabdominopelviccavities)

Abdominal cavity(contains digestiveviscera)

Diaphragm

Pelvic cavity(contains urinary bladder, reproductive organs, and rectum)

ThoracicCavity

(a) Lateral view (b) Anterior view

Dorsal body cavityVentral body cavity


Ventral Body Cavities

• Thoracic cavity subdivisions:

• Two pleural cavities

• Mediastinum

• Pericardial cavity


Ventral Body Cavities

• Abdominopelvic cavity subdivisions:

• Abdominal cavity

• Pelvic cavity


Cranialcavity

Dorsalbodycavity

Vertebralcavity

Cranialcavity

Vertebralcavity

Abdomino-pelviccavity

Ventral bodycavity

Abdominal cavity

Diaphragm

Pelvic cavity

Thoraciccavity

(a) Lateral view (b) Anterior view

Dorsal body cavityVentral body cavity


Abdominopelvic Regions

• Nine divisions used primarily by anatomists


Epigastricregion

Umbilicalregion

Rightlumbarregion

Leftlumbarregion

Righthypochondriac

region

Lefthypochondriac

region

Hypogastric(pubic)region

Right iliac(inguinal)

region

Left iliac(inguinal)

region

Liver

Gallbladder

Ascending colon oflarge intestine

Small intestine

Appendix

Cecum

Diaphragm

Stomach

Descending colonof large intestine

Transverse colonof large intestine

Initial part ofsigmoid colon

Urinary bladder

(a) Nine regions delineated by four planes (b) Anterior view of the nine regions showing the superficial organs


Abdominopelvic Quadrants

• Divisions used primarily by medical personnel


Right upperquadrant(RUQ)

Right lowerquadrant(RLQ)

Left upperquadrant(LUQ)

Left lowerquadrant(LLQ)

the human body: an orientation ch . 1a

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