1 foundations: an introduction to anatomy

© 2012 Pearson Education, Inc.

1Foundations: An Introduction to Anatomy


Introduction

• Anatomy• The study of external structures• The study of internal structures• The study of the relationship between body

parts• The careful observation of the human body


Introduction

• Physiology• The study of how the body functions• The study of mechanisms in the body


Microscopic Anatomy

• Microscopic anatomy • The study of structures that cannot be seen

without magnification• Cytology—study of cells• Histology—study of tissues


Microscopic Anatomy

• Macroscopic anatomy • The study of structures that can be seen

without magnification• Surface anatomy: refers to the superficial

anatomical markings• Regional anatomy: refers to all structures in a

specific area of the body, whether they are superficial or deep

• Systemic anatomy: The study of the organ systems of the body (digestive system, cardiovascular system, etc.)


Figure 1.1 The Study of Anatomy at Different Scales

Size

meters (m) millimeters (mm) micrometers (m) nanometers (nm)

Approximate Magnification (Reduction)FactorFrom actual to artwork on this page

Unaided human eye

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Compound lightmicroscope

Scanning electronmicroscope

Transmission electronmicroscope

( .15) ( .12) ( .6) 20 83 103 103 103 105 106 106 106 107 108

.1nm1nm2nm8–10nm11nm10–120nm120m 10m 1–12m 2m.5mm12mm120mm1.7m

Relative size m to mm Relative size mm to m Relative size m to nm


Other Perspectives on Anatomy

• Developmental anatomy: • Examines structural changes over time• Embryology:

• The study of early developmental stages

• Comparative anatomy:• Considers different types of animals

• Clinical anatomy:• Focuses on pathological changes

during illness


Other Perspectives on Anatomy

• Surgical anatomy:• Studies anatomical landmarks important for

surgical procedures• Radiographic anatomy:

• The study of anatomical structures with the use of x-rays or ultrasound scans on an intact body

• Cross-sectional anatomy:• The use of radiographic techniques (CT and

MRI scans) to look at cross sections of the body


Figure 1.2 Comparative Anatomy

Dorsal, hollow nervecord forming

brain andspinal cord

Notochorda stiffened rod belowspinal cord, usually

replaced by vertebrae

Muscular tailextends beyond

exit ofdigestive tract

Digestivetract

Mouth Heart Anus

Braincaseof cartilage or

bone surroundsthe brain

Pharyngeal (gill)arches

may persist or be modifiedto form other structures

in adult

Ventral bodycavity

contains thoracicand abdominopelvic

organs

Somitessegmental blocksforming muscles,

vertebrae, etc.

Skullsurrounds

brain incranail cavity

Limb bud

Somites

Somites

Limbbuds

Embryo

Salmon (bony fish)

Chicken

Human

Adult

Vertebraesurround

spinal cordin spinal cavity

Skull

Skull

Vertebrae

Vertebrae

The similarities betweenvertebrates are most apparentwhen comparing embryos atcomparable stages ofdevelopment.

The similarities are lessobvious when comparingadult vertebrates.

All vertebrates share a basicpattern of anatomical organizationthat differs from that of otheranimals.

BasicVertebrateBody Plan


Levels of Organization

• Chemical/Molecular (simple)• Cell• Tissue• Organ• Organ system• Organism (complex)



• Chemical/Molecular• Over a dozen elements in the body• Four of them make up 99% of the body

• Hydrogen, oxygen, carbon, and nitrogen

• Major classes of compounds• Water• Carbohydrates• Proteins• Lipids• Nucleic acids


Figure 1.3 Composition of the Body at the Chemical Level of Organization

Molecularcomposition ofthe body

Elemental composition of the body.Trace elements include silicon,fluorine, copper, manganese, zinc,selenium, cobalt, molybdenum,cadmium, chromium, tin,aluminum, and boron.

Hydrogen62%

Oxygen26%

Carbon10%

Nitrogen1.5%

Carbohydrates3%

Lipids10%

Proteins20%

Water – 66%OTHER ELEMENTS

CalciumPhosphorusPotassiumSodiumSulfurChlorineMagnesiumIronIodineTrace elements

0.2%0.2%0.06%0.06%0.05%0.04%0.03%0.0005%0.0000003%(see caption)



• Cell• The smallest living unit in the body

• Tissue• Many cells and some surrounding material

• Organ• Combination of tissues



• Organ System• Combination of various organs make up a

specific system• For example: the stomach, small intestine, large

intestine, liver, gallbladder, and pancreas make up the digestive system

• Humans are composed of 11 organ systems

• ORGANISM


Figure 1.4 Levels of Organization

Organism Level

Organ System Level

Organ Level

Tissue Level

Cellular Level

Chemical orMolecular Levels

.1nm

10nm

10m

1mm

1mm

120mm

1.7m

Size

All of the organ systems mustwork together for a person toremain alive and healthy.

IntegumentarySkeletal

MuscularNervous

EndocrineCardiovascular

Lymphoid

RespiratoryDigestive

UrinaryReproductive

The cardiovascular systemincludes the heart, the blood,and blood vessels.

The heart is acomplex three-dimensional organ.

Cardiac muscle tissueconstitutes the bulk ofthe walls of the heart.

Cardiac muscle tissueis formed from interlockingheart muscle cells.

Heart muscle cellscontain within themcontractileprotein fibers.

Complex contractileprotein fibers areorganized from molecules.

Molecules areformed frominteracting atoms.


Figure 1.5 An Introduction to Organ Systems (Part 1 of 2)

ORGAN SYSTEM MAJOR FUNCTIONS

Integumentarysystem

Skeletalsystem

Muscularsystem

Nervoussystem

Endocrinesystem

Cardiovascularsystem

Protection from environmentalhazards; temperature control

Support, protection of soft tissues;mineral storage; blood formation

Locomotion, support, heatproduction

Directing immediate responses tostimuli, usually by coordinating theactivities of other organ systems

Directing long-term changesin the activities of other organsystems

Internal transport of cells anddissolved materials, includingnutrients, wastes, and gases


Figure 1.5 An Introduction to Organ Systems (Part 2 of 2)

ORGAN SYSTEM MAJOR FUNCTIONS

Lymphoidsystem

Defense against infection anddisease

Respiratorysystem

Digestivesystem

Urinarysystem

Reproductivesystem

Delivery of air to sites where gasexchange can occur between the air and circulating blood

Processing of food andabsorption of organic nutrients,minerals, vitamins, and water

Elimination of excess water,salts, and waste products;control of pH

Production of sex cells andhormones


An Introduction to Organ Systems

• Responsiveness (irritability) • A change in activity based on a stimulus

• Adaptability • Long-term responsiveness

• Growth• The increase in size of an organism

• Differentiation• Becoming specialized to perform particular

functions



• Reproduction• The production of new generations of the

same organism• Movement

• The ability to change the position of something

• Metabolism• All the chemical reactions in the body

• Anabolism: the synthesis of complex molecules• Catabolism: the breakdown of complex molecules



• Absorption:• The process of bringing chemicals into the

body

• Respiration:• The absorption, transport, and use of oxygen

by cells

• Digestion:• The processes of catabolism that make

nutrients small enough to be absorbed

• Excretion:• The removal of wastes


HOMEOSTASIS • Homeostatic regulation is the adjustment of physiological

systems to preserve homeostasis.• Two general mechanisms are involved in homeostatic

regulation: autoregulation and extrinsic regulation:• 1. Autoregulation, (intrinsic regulation)a cell, a tissue, an

organ, or an organ system adjusts automatically in response to some environmental change.

• Example: oxygen decrease- cells release chemicals- dilate bl.vessels.

• 2. Extrinsic regulation nervous system or endocrine system control or adjust the activities of many systems .

• For example: exercise-n.s. increases heart rate & n.s. reduces blood flow to less active organs(digestive)


• nervous system directs rapid, short-term, and very specific responses. (hot stove)

• endocrine system releases chemical messengers, called hormones, that affect tissues and organs throughout the body.

• The responses may not be immediately apparent, but they may persist for days or weeks.

• Ex:regulation of blood volume and composition (starvation).

• The endocrine system also plays a major role in growth and development


• homeostatic regulatory mechanism consists of three parts:

• (1) a receptor, a sensor that is sensitive to a particular environmental change, or stimulus;

• (2) a control center, or integration center, which receives and processes the information supplied by the receptor; and

• (3) an effector, a cell or organ that responds to the commands of the control center and whose activity either opposes or enhances the stimulus.


NEGATIVE FEEDBACK • an effector activated by the control center

opposes, or negates, the original stimulus. Negative feedback thus tends to minimize change,

• Most homeostatic regulatory mechanisms involve negative feedback. (body temperature)hypothalamus,


Negative feedback


POSITIVE FEEDBACK• In positive feedback, an initial stimulus produces a

response that exaggerates or enhances the change in the original conditions rather than opposing it.

• positive feedback loops are often incorporated into control mechanisms in which a potentially dangerous or stressful process must be completed quickly.

• For example, the immediate danger from a severe cut is the loss of blood, which can lower blood pressure and reduce the efficiency of the heart. clotting gets under way, each step releases chemicals that accelerate the process. formation of a blood clot, patches the vessel wall and stops the bleeding. Also labor and delivery,


Positive feedback


Figure 1.6 The Organ Systems of the Body (Part 1 of 12)

The Integumentary System

Protects againstenvironmental hazards;helps control bodytemperature

Hair

Epidermis andassociatedglands

Fingernail



The Skeletal System

Provides support; protectstissues; stores minerals;forms blood cells

SkullAXIAL

SKELETONAPPENDICULAR

SKELETON

Sternum

Ribs

Vertebrae

Sacrum

Supporting bones(scapula andclavicle)

Upper limbbones

Pelvis (supportingbones plus sacrum)

Lower limb

bones



The Muscular System

Allows for locomotion;provides support;produces heat

Axialmuscles

Appendicularmuscles



The Nervous System

Directs immediateresponses to stimuli,usually by coordinatingthe activities of other organ systems

CENTRAL NERVOUSSYSTEM

Spinalcord

Brain

Peripheralnerves

PERIPHERAL NERVOUSSYSTEM



The Endocrine System

Directs long-termchanges in activitiesof other organsystems

Pineal glandPituitary gland

Thyroid glandParathyroid gland

Thymus

Suprarenal glandPancreas

Ovary infemale

Testis in male



The Cardiovascular System

Transports cells and dissolved materials,including nutrients,wastes, and gases

Heart

Artery

Vein

Capillaries



The Lymphoid System

Defends againstinfection and disease;returns tissue fluid tothe bloodstream

Thymus Lymph nodes

Spleen

Lymphatic vessel



The Respiratory System

Delivers air to sites wheregas exchange can occurbetween the air andcirculating blood;produces sound

Pharynx

Trachea

Lung

Diaphragm

Nasal cavity

Sinus

Larynx

Bronchi



The Digestive System

Processes food andabsorbs nutrients

Salivary gland

Stomach

Large intestine

Pharynx

Esophagus

LiverGallbladder

Pancreas

Small intestine

Anus



The Urinary System

Eliminates excesswater, salts, andwaste products

Kidney

UreterUrinarybladder

Urethra



The Male Reproductive System

Produces sex cellsand hormones

Prostate gland

Seminal gland

Ductusdeferens

Urethra

Epididymis

Testis

Penis

Scrotum



The Female Reproductive System

Produces sex cellsand hormones; supports embryonicdevelopment fromfertilization to birth

Mammary gland

Uterinetube

Ovary

Uterus

Vagina

Externalgenitalia


The Language of Anatomy

• Superficial Anatomy• Using the proper terms to identify the

structures of the body helps physicians communicate with each other and the patient

• The terms are typically derived from Latin or Greek

• Latin or Greek is used because they are descriptive languages


Figure 1.7 The Importance of Precise Vocabulary



• Anatomical Landmarks• Anatomical position

• The hands are at the side• The palms are facing forward• All discussion of the human body is in reference to

the anatomical position• Supine: lying down (face up) in the anatomical

position• Prone: lying down (face down) in the anatomical

position


Figure 1.8a Anatomical Landmarks Frons orforehead (frontal)

Craniumor skull

(cranial)

Faciesor face(facial)

Cephalonor head

(cephalic)

Oris or mouth (oral

Mentis or chin(mental)

Axilla or armpit(axillary)

Brachiumor arm

(brachial)

Antecubitisor front of

elbow(antecubital)

Antebrachiumor forearm

(antebrachial)

Carpusor wrist (carpal)

Palmaor palm

(palmar)

Pollexor thumb

Digits(phalanges)

or fingers (digitalor phalangeal)

Patellaor kneecap

(patellar)

Crus or leg (crural)

Tarsus orankle

(tarsal)

Digits (phalanges)or toes (digital or

phalangeal)Hallux or great toe

Pes or foot(pedal)

Anterior view in the anatomical position.

Femur or thigh (femoral)

Pubis (pubic)

Inguenor groin (inguinal)

Manusor hand (manual)

Pelvis (pelvic)

Umbilicusor naval (umbilical)

Abdomen (abdominal)

Mamma or breast (mammary)

Thoracis or thorax, chest(thoracic)

Cervicis or neck (cervical)

Bucca or cheek (buccal)

Auris or ear (otic)

Oculus or eye (orbital or ocular)

Nasus or nose (nasal)

Trunk



• Head and Neck Region• Frons• Nasus• Oculus• Auris• Bucca• Oris• Mentis• Cervis• Occipital (posterior head region)


Figure 1.8a Anatomical Landmarks (Part 1 of 2)Frons or

forehead (frontal)

Craniumor skull

(cranial)


Cephalonor head

(cephalic)



Brachiumor arm

(brachial)


elbow(antecubital)


(antebrachial)


Abdomen (abdominal)





Auris or ear (otic)



Trunk

Oris or mouth (oral



• Torso Region• Thoracis• Mamma• Abdomen• Umbilicus• Pelvis • Dorsum• Lumbus



forehead (frontal)

Craniumor skull

(cranial)


Cephalonor head

(cephalic)



Brachiumor arm

(brachial)


elbow(antecubital)


(antebrachial)


Abdomen (abdominal)





Auris or ear (otic)



Trunk

Oris or mouth (oral


Figure 1.8b Anatomical Landmarks (Part 1 of 2)

Shoulder(acromial)

Dorsum or(back

(dorsal)

Olecranonor back

of elbow(olecranal)

Lumbusor loin

(lumbar)

Upper limb


Cephalon or head (cephalic)


Figure 1.8a Anatomical Landmarks (Part 2 of 2)Antebrachium

or forearm(antebrachial)


Palmaor palm

(palmar)

Pollexor thumb

Digits(phalanges)


Patellaor kneecap

(patellar)Crus or

leg (crural)

Tarsus orankle

(tarsal)



Pes or foot(pedal)


Pubis (pubic)



Pelvis (pelvic)



• The Arm and Hand• Brachium• Antecubitis• Antebrachium• Carpus• Palma• Pollex • Axilla• Olecranon (cubitis)



forehead (frontal)

Craniumor skull

(cranial)


Cephalonor head

(cephalic)



Brachiumor arm

(brachial)


elbow(antecubital)


(antebrachial)


Abdomen (abdominal)





Auris or ear (otic)



Trunk

Oris or mouth (oral





Palmaor palm

(palmar)

Pollexor thumb

Digits(phalanges)


Patellaor kneecap

(patellar)Crus or

leg (crural)

Tarsus orankle

(tarsal)



Pes or foot(pedal)


Pubis (pubic)



Pelvis (pelvic)



Shoulder(acromial)

Dorsum or(back

(dorsal)

Olecranonor back

of elbow(olecranal)

Lumbusor loin

(lumbar)

Upper limb


Cephalon or head (cephalic)



• The Leg and Foot• Inguen• Pubis• Femur• Patella• Crus• Tarsus• Hallux



• The Leg and Foot (continued)• Gluteus• Gluteal cleft (natal cleft)• Gluteal fold• Popliteus• Sura• Calcaneus• Planta • Hallux





Palmaor palm

(palmar)

Pollexor thumb

Digits(phalanges)


Patellaor kneecap

(patellar)Crus or

leg (crural)

Tarsus orankle

(tarsal)



Pes or foot(pedal)


Pubis (pubic)



Pelvis (pelvic)



Gluteusor buttock

(gluteal)

Popliteus orback of knee

(popliteal)

Suraor calf (sural)

Calcaneus orheel of foot(calcaneal)

Planta orsole of foot (plantar)

Lower limb



• Abdominopelvic quadrants and regions• Anatomists and clinicians use specialized

regional terms to indicate a specific area of concern within the abdomen or the pelvic regions of the body.

• The abdomen and pelvic regions can be subdivided into four regions (abdominopelvic quadrants)

• The abdomen and pelvic regions can be subdivided into nine regions (abdominopelvic regions)



• Abdominopelvic quadrants and regions• Abdominopelvic quadrants

• Right upper quadrant (RUQ)• Left upper quadrant (LUQ)• Right lower quadrant (RLQ)• Left lower quadrant (LLQ)


Figure 1.9a Abdominopelvic Quadrants and Regions

Right Upper Quadrant (RUQ)

Right Lower Quadrant (RLQ)

Left Upper Quadrant (LUQ)

Left Lower Quadrant (LLQ)

Right lobe of liver, gallbladder,right kidney, portions of stomach,small and large intestine

Cecum, appendix, andportions of small intestine,reproductive organs (rightovary in female and rightspermatic cord in male),and right ureter

Left lobe of liver, stomach,pancreas, left kidney, spleen,portions of large intestine

Most of small intestine andportions of large intestine,left ureter, and reproductiveorgans (left ovary in femaleand left spermatic cordin male)

Abdominopelvic quadrants divide the area intofour sections. These terms, or their abbreviations,are most often used in clinical discussions.



• Abdominopelvic quadrants and regions• Abdominopelvic regions

• Epigastric• Right hypochondriac• Left hypochondriac• Umbilical• Right lumbar• Left lumbar• Hypogastric• Right inguinal• Left inguinal


Figure 1.9b Abdominopelvic Quadrants and Regions

More precise anatomical descriptions are provided byreference to the appropriate abdominopelvic region.

Left hypochondriacregion

Left lumbarregion

Left inguinalregion

Right inguinalregion

Right lumbarregion

Righthypochondriac

region

Epigastricregion

Umbilicalregion

Hypogastricregion



• Abdominopelvic quadrants and regions• Select organs found within the abdominopelvic

quadrants• RUQ: Most of the liver, gallbladder• LUQ: Most of the stomach, spleen• RLQ: cecum, appendix, right ureter, right ovary,

right spermatic cord• LLQ: left ureter, left ovary, left spermatic cord




regions• Epigastric: left lobe of liver• Right hypochondriac: right lobe of liver, liver fundus• Left hypochondriac: stomach fundus, spleen




regions• Umbilical: small intestine, transverse colon• Right lumbar: ascending colon• Left lumbar: descending colon




regions• Hypogastric: urinary bladder, appendix (position

varies), major portion of the small intestine• Right inguinal: cecum, appendix (position varies)• Left inguinal: sigmoid colon


Figure 1.9c Abdominopelvic Quadrants and Regions

Quadrants or regions are useful because there is aknown relationship between superficial anatomicallandmarks and underlying organs.

Stomach

Spleen

Urinary bladder

Liver

Gallbladder

Large intestine

Small intestine

Appendix



• Anatomical directions• The most common directional terms used are:

• Superior• Inferior• Anterior• Posterior • Medial • Lateral• Superficial• Deep


Figure 1.10 Directional ReferencesSUPERIOR SUPERIOR

INFERIOR INFERIOR

Anterior viewLateral view

Right Left

Proximal

Lateral Medial

Distal

Distal

Proximal

Posterioror dorsal

Anterioror ventral

Cranial

Caudal


Table 1.2 Regional and Directional Terms



• Sectional Anatomy• There are many different ways to dissect a

piece of tissue for further study. These are referred to as dissectional cuts or dissectional planes.

• Sagittal cut (midsagittal and parasagittal)• Transverse cut• Frontal cut• Oblique cut



• Sectional Anatomy• Sagittal cut: separating left and right

• Midsagittal: separating left and right equally• Parasagittal: separating left and right unequally

• Transverse cut: separating superior and inferior

• Frontal cut: separating anterior and posterior

• Oblique cut: separating the tissue at an angle


Figure 1.11 Planes of Section

Frontal plane

Transverse plane

Sagittal plane


Table 1.3 Terms That Indicate Planes of Section


Figure 1.12 Sectional Planes and Visualization



• Sectional Anatomy: Body cavities• If you remove an organ from the body, you

will leave a cavity• The body cavities are studied in this manner:

• Posterior cavity• Anterior cavity



• Sectional Anatomy: Body cavities• Posterior cavity

• Cranial cavity: consists of the brain• Spinal cavity: consists of the spinal cord



• Sectional Anatomy: Body cavities• Anterior cavity

• Thoracic cavity• Abdominal cavity• Pelvic cavity

Abdominopelvic cavity



• Sectional Anatomy: Anterior cavity• Thoracic cavity consists of:

• Pleural cavity: lungs• Pericardial cavity: heart• Mediastinal cavity: space between the apex of

the lungs



• Sectional Anatomy: Anterior cavity• Abdominopelvic cavity consists of:

• Peritoneal cavity: stomach, intestines, spleen, liver, etc.

• Pelvic cavity: urinary bladder



• Sectional Anatomy: Body cavities• Each cavity consists of a double-layered

membrane• The membrane nearest the wall of the body

(farthest from the organs) is the parietal membrane

• parietal pleura, parietal pericardium, parietal peritoneum

• The membrane farthest from the wall of the body (nearest the organs) is the visceral membrane

• visceral pleura, visceral pericardium, visceral peritoneum


Figure 1.14 The Ventral Body Cavity

Ventral Body Cavity (Coelom)

Thoracic Cavity Abdominopelvic Cavity

Right Pleural Cavity Mediastinum Left Pleural Cavity

Pericardial Cavity

Abdominal Cavity Pelvic Cavity

• Provides protection• Allows organ movement• Lining prevents friction

Surrounded by chest wall anddiaphragm

Surrounds right lung

Contains thetrachea, esophagus,and major vessels

Surrounds heart

Surrounds left lung

Contains the peritonealcavity

Contains manydigestive glandsand organs

Contains urinary bladder,reproductiveorgans, last portionof digestive tract

Separated by diaphragm into

subdivided into includes the

also contains


Figure 1.13ab Body Cavities

POSTERIOR ANTERIOR

Pleuralcavity

Thoraciccavity

Pericardialcavity

Diaphragm

Peritonealcavity

Abdominalcavity

Pelvic cavity

Abdominopelviccavity

Lateral view of the subdivisions of the ventral body cavities.The muscular diaphragm separates the superior thoracic(chest) cavity and the inferior abdominopelvic cavity.

The heart projects into thepericardial cavity like a fistpushed into a balloon.

Heart

Visceralpericardium

Pericardialcavity

Parietalpericardium

Air space

Balloon


Figure 1.13cd Body Cavities

Anterior view of theventral body cavityand its subdivisions

Peritonealcavity

Pleural cavity

Pericardialcavity

Diaphragm

Pelviccavity

Sectional view of the thoracic cavity. Unless otherwisenoted, all sectional views are presented in inferiorview. (See Clinical Note on pp. 22–23 for more details.)

Sternum

Heart inpericardial

cavityPleural cavity

Pleura

Mediastinum

Spinal cord

Rightlung

RightlungLeft

lung

Leftlung

1 foundations: an introduction to anatomy

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