chapter 1: the human body… an orientation and introduction

Chapter 1: The Human Body… An Orientation and

Introduction

Copyright © 2010 Pearson Education, Inc.

Figure 1.1 Levels of structural organization.

Cardiovascularsystem

OrganelleMoleculeAtoms

Chemical levelAtoms combine to form molecules.

Cellular levelCells are made up ofmolecules.

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

12

3

4

56


Figure 1.2 Examples of interrelationships among body organ systems.

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


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

NailsSkin

Hair

(a) Integumentary System Forms the external body covering, and protects deeper tissues from injury. Synthesizes vitamin D, and houses cutaneous (pain, pressure, etc.) receptors and sweat and oil glands.


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

Bones

Joint

(b) Skeletal System Protects 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 System Allows manipulation of the environment, locomotion, and facial expression. Main- tains posture, and produces heat.


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

Brain

NervesSpinalcord

(d) Nervous System As the fast-acting control system of the body, it responds to internal and external changes by activating appropriate muscles and glands.


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

Pineal gland

Pituitarygland

ThyroidglandThymus

AdrenalglandPancreas

Testis

Ovary

(e) Endocrine System Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells.


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

Lymphaticvessels

Red bonemarrow

Thoracicduct

Thymus

Spleen

Lymphnodes

(g) Lymphatic System/Immunity Picks up fluid leaked from blood vessels and returns it to blood. Disposes of debris in the lymphatic stream. Houses white blood cells (lymphocytes) involved in immunity. The immune response mounts the attack against foreign substances within the body.


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

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

Heart

Bloodvessels


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

Nasalcavity

BronchusPharynx

LarynxTrachea

Lung

(h) Respiratory System Keeps blood constantly supplied with oxygen and removes carbon dioxide. The gaseous exchanges occur through the walls of the air sacs of the lungs.


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

Liver

Oral cavity

Esophagus

Largeintestine

StomachSmallintestine

RectumAnus

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


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

Kidney

Ureter

UrinarybladderUrethra

(j) Urinary System Eliminates nitrogenous wastes from the body. Regulates water, electrolyte and acid-base balance of the blood.


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

Prostategland

Ductusdeferens

Penis

Testis

Scrotum

Ovary

Uterinetube

Mammaryglands (inbreasts)

Uterus

Vagina

Overall function is production of offspring. Testes produce sperm and male sexhormone, and male ducts and glands aid in delivery of sperm to the femalereproductive tract. Ovaries produce eggs and female sex hormones. The remainingfemale structures serve as sites for fertilization and development of the fetus.Mammary glands of female breasts produce milk to nourish the newborn.

(k) Male Reproductive System (l) Female Reproductive System


Figure 1.4 Interaction among the elements of a homeostatic control system.

Stimulusproduceschange invariable.

Receptordetects change.

Input: Information sent along afferent pathway to control center.

Output:Information sent along efferent pathway to effector.

Responseof effector feeds back to reduce the effect ofstimulus and returns variable to homeostatic level.

Receptor Effector

ControlCenter

1

2

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5

BALANCE

Afferentpathway

Efferentpathway


Figure 1.5 Regulation of body temperature by a negative feedback mechanism.

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


Figure 1.6 Summary of the positive feedback mechanism regulating formation of a platelet plug.

Feedback cycle endswhen plug is formed.

Positive feedbackcycle is initiated.

Positivefeedbackloop

Break or tearoccurs in blood vessel wall.

Plateletsadhere to site and release chemicals.

Released chemicals attract more platelets.

Platelet plugforms.

2

1

3

4


Figure 1.7 Regional terms used to designate specific body areas.

CervicalCervical

Back (dorsal)

(a) Anterior/Ventral (b) Posterior/Dorsal

Pubic (genital)

Cephalic Frontal Orbital Nasal Oral Mental

Thoracic Sternal Axillary Mammary

Scapular

Vertebral

Lumbar

Sacral

Gluteal

Perineal (between anus and external genitalia)

Abdominal Umbilical

Pelvic Inguinal

(groin)

Upper limb Acromial

Brachial (arm) Antecubital Olecranal Antebrachial

(forearm) Carpal (wrist)

Manus (hand) Pollex Metacarpal Palmar Digital

Lower limb Coxal (hip) Femoral (thigh) Patellar Popliteal Crural (leg) Sural (calf) Fibular or peroneal

Pedal (foot) Tarsal (ankle) Calcaneal Metatarsal Digital Plantar Hallux

Cephalic Otic Occipital (back

of head)

ThoraxAbdomenBack (Dorsum)


Figure 1.8 Planes of the body with corresponding magnetic resonance imaging (MRI) scans.

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)


Figure 1.9 Dorsal and ventral body cavities and their subdivisions.

Cranialcavity(contains brain)

Dorsalbodycavity

Vertebralcavity(contains spinal cord)

Cranialcavity

Superiormediastinum

Pericardialcavity withinthe mediastinum

Pleuralcavity

Vertebralcavity

Abdomino-pelviccavity

Ventral bodycavity(thoracic andabdominopelviccavities)

Abdominal cavity(contains digestiveviscera)

Diaphragm

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

Thoraciccavity(containsheart andlungs)

(a) Lateral view (b) Anterior view

Dorsal body cavityVentral body cavity


Figure 1.11 The four abdominopelvic quadrants.

Right upperquadrant(RUQ)

Right lowerquadrant(RLQ)

Left upperquadrant(LUQ)

Left lowerquadrant(LLQ)


Figure 1.12 The nine abdominopelvic regions.

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


Table 1.1 Orientation and Directional Terms (1 of 3)

chapter 1: the human body… an orientation and introduction

Documents

body organ systems

bodys organ systems

pearson education

body cells

organ level organs

major functions

external body

body organs