an orientation the human body - anatomy and...

Lecture Presentation by Patty Bostwick-Taylor

Florence-Darlington Technical College

Chapter 1

The Human Body: An Orientation

© 2015 Pearson Education, Inc.


The Human Body—An Orientation

Anatomy▪Study of the structure and shape of the body and its parts▪Observation is used to see sizes and relationships of parts


Anatomy—Levels of Study

▪Gross anatomy▪ Large structures▪Easily observable



▪Let’s look at an example of gross anatomy using the digestive system organs


Figure 14.1 The human digestive system: Alimentary canal and accessory organs.

Mouth (oral cavity)Tongue

Esophagus

Parotid glandSublingual glandSubmandibulargland

Salivary glands

Pharynx

StomachPancreas(Spleen)

Transverse colonDescending colon

Ascending colon

CecumSigmoid colonRectumAppendixAnal canal

Anus

Smallintestine

DuodenumJejunumIleum

Liver

Gallbladder

Large intestine


Anatomy—Levels of Study

▪Microscopic anatomy▪Structures cannot be seen with the naked eye▪Structures can be viewed only with a microscope


Figure 14.4c Anatomy of the stomach.

Pyloricsphincter

Gastric pits

Gas

tric

pi

tG

astr

ic g

land

Surfaceepithelium

Mucousneck cells

Parietal cells

GastricglandsChief cells

(c)


Figure 14.4d Anatomy of the stomach.

Chief cells

Enteroendocrinecell

(d)

PepsinogenHCI

Pepsin

Parietal cells



Physiology▪Study of how the body and its parts work or function


Relationship between Anatomy and Physiology▪Structure determines what functions can occur▪ If structure changes, the function must also change


Levels of Structural Organization

▪Six levels of structural organization1. Atoms2. Cells3. Tissues4. Organs5. Organ systems6. Organisms


Figure 1.1 Levels of structural organization.

Chemical levelAtoms combine toform molecules.

1

AtomsMolecules

Smooth muscle cell

Cellular levelCells are madeup of molecules.

2

Tissue levelTissues consist ofsimilar types of cells.

3

Organ levelOrgans are made up ofdifferent types of tissues.

4

Organ system levelOrgan systems consist ofdifferent organs that worktogether closely.

5 Organismal levelHuman organisms aremade up of many organsystems.

6

Smoothmuscletissue

Bloodvessel(organ)

Epithelialtissue

Smoothmuscletissue

Connectivetissue

Bloodvessels

Heart

Cardio–vascularsystem

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AtomsMolecules

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AtomsMolecules

Smooth muscle cell


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AtomsMolecules

Smooth muscle cell


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Smoothmuscletissue

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AtomsMolecules

Smooth muscle cell


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Smoothmuscletissue

Bloodvessel(organ)

Epithelialtissue

Smoothmuscletissue

Connectivetissue

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AtomsMolecules

Smooth muscle cell


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Smoothmuscletissue

Bloodvessel(organ)

Epithelialtissue

Smoothmuscletissue

Connectivetissue

Bloodvessels

Heart


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AtomsMolecules

Smooth muscle cell


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5 Organismal levelHuman organisms aremade up of many organsystems.

6

Smoothmuscletissue

Bloodvessel(organ)

Epithelialtissue

Smoothmuscletissue

Connectivetissue

Bloodvessels

Heart


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Organ System Overview

▪ Integumentary system▪ Forms the external body covering (skin)▪Protects deeper tissue from injury▪Helps regulate body temperature▪ Location of cutaneous nerve receptors


Figure 1.2a The body’s organ systems.

(a) Integumentary System

Forms the external body covering; protectsdeeper tissue from injury; synthesizesvitamin D; location of cutaneous receptors(pain, pressure, etc.) and sweat and oil glands.

Skin



▪Skeletal system▪Consists of bones, cartilages, ligaments, and joints▪Supports the body▪Provides muscle attachment for movement▪Site of blood cell formation (hematopoiesis)▪Stores minerals


Figure 1.2b The body’s organ systems.

(b) Skeletal System

Protects and supports body organs; provides aframework the muscles use to cause movement;blood cells are formed within bones; storesminerals.

Joint

Cartilages

Bones



▪Muscular system▪Skeletal muscles contract or shorten▪Produces movement of bones


Figure 1.2c The body’s organ systems.

Skeletalmuscles

(c) Muscular System

Allows manipulation of the environment,locomotion, and facial expression; maintainsposture; produces heat.



▪Nervous system▪ Fast-acting control system▪Consists of brain, spinal cord, nerves, and sensory receptors▪Responds to internal and external change▪Sends messages via nerve impulses to central nervous system ▪Central nervous system activates effectors (muscles and glands)


Figure 1.2d The body’s organ systems.

BrainSensory receptor

Spinal cord

Nerves

(d) Nervous System

Fast-acting control system of the body;responds to internal and external changes byactivating appropriate muscles and glands.



▪Endocrine system▪Endocrine glands include:

▪ Pituitary gland▪ Thyroid and parathyroids▪ Adrenal glands▪ Thymus▪ Pancreas▪ Pineal gland▪ Ovaries (females) and testes (males)



▪Endocrine system▪Secretes regulatory hormones

▪ Growth▪ Reproduction▪ Metabolism


Figure 1.2e The body’s organ systems.

(e) Endocrine System

Glands secrete hormones that regulateprocesses such as growth, reproduction, andnutrient use by body cells.

Pineal glandPituitary gland

Thyroid gland (parathyroidglands on posterior aspect)

Thymus glandAdrenal glandsPancreasTestis (male)Ovary (female)



▪Cardiovascular system▪ Includes heart and blood vessels

▪ Heart pumps blood▪ Vessels transport blood to tissues

▪ Transports materials in body via blood pumped by heart▪ Oxygen and carbon dioxide▪ Nutrients▪ Wastes


Figure 1.2f The body’s organ systems.

Heart

Bloodvessels

(f) Cardiovascular System

Blood vessels transport blood, which carriesoxygen, carbon dioxide, nutrients, wastes, etc.;the heart pumps blood.



▪Lymphatic system▪ Includes lymphatic vessels, lymph nodes, and lymphoid organs▪Returns leaked fluids back to blood vessels▪Cleanses the blood▪ Involved in immunity


Figure 1.2g The body’s organ systems.

(g) Lymphatic System

Picks up fluid leaked from blood vessels andreturns it to blood; disposes of debris in thelymphatic stream; houses white blood cellsinvolved in immunity.

Thoracic duct

Lymph nodes

Lymphatic vessels



▪Respiratory system▪ Includes the nasal passages, pharynx, larynx, trachea, bronchi, and lungs▪Supplies blood with oxygen▪Removes carbon dioxide


Figure 1.2h The body’s organ systems.

(h) Respiratory System

Keeps blood constantly supplied with oxygenand removes carbon dioxide; the gaseousexchanges occur through the walls of the airsacs of the lungs.

Nasal cavityPharynxLarynxTracheaBronchusLeft lung



▪Digestive system▪ Includes the oral cavity, esophagus, stomach, small and large intestines, and accessory organs▪Breaks down food▪Allows for nutrient absorption into blood▪Eliminates indigestible material as feces


Figure 1.2i The body’s organ systems.

(i) Digestive System

Breaks food down into absorbable units thatenter the blood for distribution to body cells;indigestible foodstuffs are eliminated as feces.

Anus

Rectum

Large intestine

Small intestineStomach

EsophagusOral cavity



▪Urinary system▪ Includes the kidneys, ureters, urinary bladder, and urethra▪Eliminates nitrogenous wastes▪Maintains acid-base balance▪Regulates water and electrolytes


Figure 1.2j The body’s organ systems.

Kidney

UreterUrinary bladder

Urethra

(j) Urinary System

Eliminates nitrogen-containing wastes fromthe body; regulates water, electrolyte, andacid-base balance of the blood.



▪Reproductive system▪ For males, includes the testes, scrotum, penis, accessory glands, and duct system▪ Testes produce sperm▪ Duct system carries sperm to exterior

▪ For females, includes the ovaries, uterine tubes, uterus, and vagina▪ Ovaries produce eggs▪ Uterus provides site of development for fetus


Figure 1.2k-l The body’s organ systems.

(k) Male Reproductive System

Overall function of the reproductive system is production of offspring. Testes producesperm and male sex hormone; ducts and glands aid in delivery of viable sperm to thefemale reproductive tract. Ovaries produce eggs and female sex hormones; remainingstructures serve as sites for fertilization and development of the fetus. Mammaryglands of female breast produce milk to nourish the newborn.

(l) Female Reproductive System

Prostate gland

Vas deferens

TestisScrotum

Seminalvesicles

Penis

Mammary glands(in breasts)Uterine tube

OvaryUterus

Vagina


Maintaining Life: Necessary Life Functions

▪Maintain boundaries▪Movement

▪ Locomotion▪Movement of substances

▪Responsiveness▪Ability to sense changes and react

▪Digestion▪Breakdown and absorption of nutrients


Necessary Life Functions

▪Metabolism—chemical reactions within the body▪Break down complex molecules into smaller ones▪Build larger molecules from smaller ones▪Produces energy▪Regulated by hormones

▪Excretion▪Eliminates waste from metabolic reactions▪Wastes may be removed in urine or feces


Necessary Life Functions

▪Reproduction▪Occurs on cellular level or organismal level▪Produces future generation

▪Growth▪ Increases cell size and number of cells


Survival Needs

▪Nutrients▪Chemicals for energy and cell building▪ Includes carbohydrates, proteins, lipids, vitamins, and minerals

▪Oxygen▪Required for chemical reactions


Survival Needs

▪Water▪ 60 to 80 percent of body weight▪Most abundant chemical in the human body▪Provides for metabolic reactions

▪Stable body temperature▪ 37°C (98°F)

▪Atmospheric pressure ▪Must be appropriate for gas exchange


Figure 1.3 Examples of selected interrelationships among body organ systems.

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

Respiratory systemTakes in oxygen and eliminatescarbon dioxide

Cardiovascular systemVia the blood, distributes oxygenand nutrients to all body cells anddelivers wastes and carbondioxide to disposal organs

Urinary systemEliminatesnitrogen-containingwastes andexcess ions

Food O2 CO2

CO2O2

Blood

Heart

Interstitial fluid

Nutrients

Nutrients and wastes passbetween blood and cellsvia the interstitial fluid

Feces UrineIntegumentary systemProtects the body as a wholefrom the external environment


Homeostasis

▪Homeostasis—maintenance of a stable internal environment ▪A dynamic state of equilibrium▪Necessary for normal body functioning and to sustain life

▪Homeostatic imbalance▪A disturbance in homeostasis results in disease


Figure 1.4 The elements of a homeostatic control system.

Stimulusproduceschange invariable.

1

Receptordetects change.2

Input: Informationis sent along afferentpathway to controlcenter.

3

Receptor

Afferentpathway

ControlCenter

Efferentpathway

Effector

Output: Informationis sent along efferentpathway effector.

4

Responseof effector feedsback to reducethe effect ofstimulus andreturns variableto homeostaticlevel.

5

VARIABLE (in homeostasis)

IMBALANCE

IMBALANCE

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IMBALANCE

IMBALANCE

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Receptor


IMBALANCE

IMBALANCE

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3

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Afferentpathway

ControlCenter


IMBALANCE

IMBALANCE

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Afferentpathway

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Afferentpathway

ControlCenter

Efferentpathway

Effector


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Responseof effector feedsback to reducethe effect ofstimulus andreturns variableto homeostaticlevel.

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IMBALANCE

IMBALANCE

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Maintaining Homeostasis

▪The body communicates through neural and hormonal control systems▪Receptor

▪ Responds to changes in the environment (stimuli)▪ Sends information to control center along an afferent

pathway


Maintaining Homeostasis

▪Control center▪ Determines set point▪ Analyzes information▪ Determines appropriate response

▪Effector▪ Provides a means for response to the stimulus▪ Information flows from control center to effector along

efferent pathway


Feedback Mechanisms

▪Negative feedback▪ Includes most homeostatic control mechanisms▪Shuts off the original stimulus or reduces its intensity▪Works like a household thermostat


Feedback Mechanisms

▪Positive feedback▪ Increases the original stimulus to push the variable farther▪Reaction occurs at a faster rate▪ In the body positive feedback occurs in blood clotting and during the birth of a baby


The Language of Anatomy

▪Special terminology is used to prevent misunderstanding▪Exact terms are used for:

▪Position▪Direction▪Regions▪Structures


The Language of Anatomy

▪Anatomical position▪Standard body position used to avoid confusion▪ Terminology refers to this position regardless of actual body position▪Stand erect, feet parallel, arms hanging at the sides with palms facing forward

Anatomical Position▪Same body position and reference points ▪Anatomical position:

▪Standing erect▪ Face forward▪Arms at the sides▪Palms and toes directed forward


Anatomical Position


Directional TermsExplains location of one body structure in relation to another


Directional Terms

▪Superior (cranial or cephalad): toward the head or upper part of a structure or the body; above ▪ Inferior (caudal): away from the head or toward the lower part of a structure or the body; below


Directional Terms

▪Ventral (anterior): toward or at the front of the body; in front of▪Dorsal (posterior): toward or at the backside of the body; behind


Table 1.1 Orientation and Directional Terms (1 of 3).


Directional Terms

▪Medial: toward or at the midline of the body; on the inner side of▪Lateral: away from the midline of the body; on the outer side of▪ Intermediate: between a more medial and a more lateral structure


Directional Terms

▪Proximal: close to the origin of the body part or point of attachment to a limb to the body trunk▪Distal: farther from the origin of a body part or the point of attachment of a limb to the body trunk


Directional Terms

▪Superficial (external): toward or at the body surface▪Deep (internal): away from the body surface; more internal


Regional Terms

▪Anterior (ventral) body landmarks


Figure 1.5a Regional terms used to designate specific body areas.

FrontalCephalic

OrbitalNasalBuccalOralMental

CervicalThoracicSternalAxillary

AbdominalUmbilical

PelvicInguinal(groin)

Pubic (genital)

KEY:ThoraxAbdomen

(a) Anterior/Ventral

Upper limbUpper limbAcromialDeltoidBrachial (arm)Antecubital

Antebrachial(forearm)Carpal (wrist)

Manus (hand)Digital

Lower limbCoxal (hip)Femoral (thigh)Patellar

Crural (leg)

FibularPedal (foot)Tarsal (ankle)

Digital


Regional Terms

▪Posterior (dorsal) body landmarks


Figure 1.5b Regional terms used to designate specific body areas.

(b) Posterior/Dorsal

Upper limbUpper limbAcromial

Brachial (arm)

OlecranalAntebrachial(forearm)

Manus (hand)Digital

Femoral (thigh)

Popliteal

Fibular

Pedal (foot)Calcaneal

Plantar

Occipital(back of head)

Cephalic

Cervical

Back (dorsal)Scapular

Vertebral

Lumbar

Sacral

Gluteal

Sural (calf) KEY:

Back (Dorsum)


Body Planes and Sections

▪Sections are cuts along imaginary lines known as planes▪Three types of planes or sections exist as right angles to one another

▪ http://www.madsci.org/~lynn/VH/planes.html

http://www.madsci.org/~lynn/VH/planes.html

http://www.madsci.org/~lynn/VH/planes.html


Figure 1.6 The anatomical position and planes of the body—median, frontal, and transverse with corresponding MRI scans.

(a) Median (midsagittal) (b) Frontal (coronal) plane (c) Transverse plane

Vertebral column

Rectum Intestines

Right lung Left lungHeart

Liver Stomach Spleen

Liver Aorta Pancreas Spleen

Spinal cordSubcutaneousfat layer


Body Planes and Sections

▪A sagittal section divides the body (or organ) into left and right parts▪A midsagittal, section divides the body (or organ) into equal left and right parts▪A frontal, or coronal, section divides the body (or organ) into anterior and posterior parts ▪A transverse, or cross, section divides the body (or organ) into superior and inferior parts


Body Cavities

▪Two body cavities▪Dorsal▪Ventral

▪Body cavities provide protection to organs within them


Figure 1.7 Body cavities.

Cranialcavity

Thoraciccavity

Diaphragm

AbdominalcavitySpinal

cavity

Pelviccavity A

bd

om

inope

lvic

cavit

y

KEY:Dorsal body cavity Ventral body cavity


Body Cavities

▪Dorsal body cavity has two subdivisions1. Cranial cavity

▪ Houses the brain▪ Protected by the skull

2. Spinal cavity ▪ Houses the spinal cord▪ Protected by the vertebrae

Membranes that line the dorsal body cavity and cover the organs within are called MENINGES


Body Cavities

▪Ventral body cavity has two subdivisions separated by the diaphragm1. Thoracic cavity2. Abdominopelvic cavity


Body Cavities

▪Thoracic cavity ▪Cavity superior to the diaphragm▪Houses heart, lungs, and other organs▪Mediastinum, the central region, houses heart, trachea, and other organs

Thoracic Cavity - Pleural Cavity

▪ Left and Right Portions▪ Contains lungs▪ Pleura - visceral pleura - covers organ

parietal pleura - lines cavity▪ Pleural Cavity - space (filled the Pleural fluid)


Body Cavities

▪Medial Portion - Mediastinum ▪Contains the heart, thymus gland, trachea, esophagus…..▪Pericardium - Visceral and Parietal▪Pericardial cavity - space filled with pericardial fluid


Body Cavities

▪Abdominopelvic cavity▪Cavity inferior to the diaphragm▪Superior abdominal cavity contains the stomach, liver, and other organs▪ Protected only by trunk muscles

▪ Inferior pelvic cavity contains reproductive organs, bladder, and rectum ▪ Protected somewhat by bony pelvis

▪No physical structure separates abdominal from pelvic cavities

Membranes that line the abdominopelvic cavity and cover the organs within are called PERITONEUM.


Review: Membranes of body cavities

▪ If lining the cavity it’s a parietal membrane▪ Lining thoracic cavity = parietal pleura▪ Lining abdominopelvic cavity-parietal peritoneum▪ Lining the pericardial cavity – parietal pericardium

▪ If covering an organ within a cavity it’s a visceral membrane▪Covering the lungs in the thoracic cavity = visceral pleura▪Covering the stomach in the abdominopelvic cavity = visceral peritoneum▪Covering the heart = visceral pericardium


Body cavities

▪Space between the visceral and parietal membranes ▪ In thoracic cavity = pleural fluid▪ In abdominopelvic cavity = peritoneal fluid

This is serous fluid that is there for cushioning, protection, and to reduce friction so organs can move around a little, expand, etc.

Greater Omentum

▪a peritoneal membrane▪ “apron of fat” ▪Covers the anterior aspect of the small intestine

Lesser Omentum

▪Peritoneal membrane▪Suspends the superior border of the stomach to the liver

Mesentery

▪ Encircles and holds the small intestine to the dorsal wall of the abdominopelvic cavity


Body Cavities

▪Abdominopelvic cavity subdivisions▪ Four quadrants▪Nine regions


Figure 1.8 The four abdominopelvic quadrants.

Left upperquadrant(LUQ)

Left lowerquadrant(LLQ)

Right upperquadrant(RUQ)

Right lowerquadrant(RLQ)


Figure 1.9 The nine abdominopelvic regions.

Righthypochondriac

region

Lefthypochondriac

region

Epigastricregion

Umbilicalregion

Rightlumbarregion

Leftlumbarregion

Right iliac(inguinal)

region

Left iliac(inguinal)

region

Hypo-gastric(pubic)region

(a) Nine regions delineated by four planes

(b) Anterior view of the nine regions showing the superficial organs

Liver

Gallbladder

Ascendingcolon oflarge intestineSmall intestineCecumAppendix

DiaphragmStomachTransversecolon of largeintestineDescendingcolon of largeintestineInitial partof sigmoidcolonUrinarybladder


Body Cavities

▪Other body cavities include:▪Oral and digestive cavities▪Nasal cavity▪Orbital cavities▪Middle ear cavities

an orientation the human body - anatomy and...

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