An Introduction to Anatomy

Chapter 1

Introduction to Anatomy

• Anatomy is a broad field of science in which the body is studied at different levels.

• Definition of anatomy (“to cut up”):

study of internal and external structures and the physical relationship between body parts

• Physiology is the study of body function:

“Structure Determines Function”

Anatomy Terminology

Language of Anatomy: Mastery of this language is essential for your success in this class

A. Pay attention to Greek and Latin roots (Appendix, p. 822)

B. To learn this new language it is recommended to:- create vocabulary flashcards pertaining to each chapter - practice the new vocabulary consistently- recognize that different terms can be used to describe the same structure (Appendix, p. 823)

The Language of Anatomy

Metric System (Appendix, p. 820-821)

Length, volume, weight are measured in metric units

• Length

• Volume

• Weight

Anatomical Variability

• Structures presented in books are largely representative of  those found in individuals

• Due to genetic diversity every individual is not structurally identical

• Neither do sensory organs perceive the environment in exactly the same way.

Study of Anatomy at Different ScalesA

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Transmission electron microscope

Scanning electron microscope

Compound light microscope

Unaided human eye

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Branches of Anatomy• Gross or macroscopic

- surface: study of general form (morphology)- regional: superficial and internal features in a specific body area- systemic: structure of major organ systems

• Microscopic (histology) anatomy - cytology

• Developmental - from conception to physical maturity

• Comparative – anatomical organization of different animals

• Clinical – anatomical features that undergo changes during illness

• Radiographic – structures visualized by imaging techniques- cross-sectional

• Surgical – studies landmarks important for surgery

Comparative Anatomy

Dorsal, hollow nervecord forming

brain andspinal cord

Notochorda stiffened rod belowspinal cord, usually

replaced by vertebrae

Digestivetract

MouthHeart Anus

Limb bud

Muscular tailextends beyond

exit ofdigestive tract

Braincaseof cartilage or

bone surroundsthe brain

Pharyngeal (gill) archesmay persist or be modified

to form other structuresin adult

Somitessegmental blocksforming muscles,

vertebrae, etc.

Somites

Salmon (bony fish)

Skull

Vertebrae

Skullsurrounds

brain incranial cavity

Vertebraesurround

spinal cord inspinal cavity

Ventral body cavitycontains thoracic

and abdominopelvicorgans Somites

Skull

Vertebrae

Limbbuds

Chicken

HumanLE 1-2

• Tube-within-a-tube body plan - inner tube extends from mouth to anus (respiratory and digestive organs)- outer tube consists of axial skeleton, associated axial muscles, and nervous structures that make up the outer body wall

• Bilateral symmetry – left half a mirror image of right- body structures such as hands, eyes, ovaries occur in pairs- median plane structures unpaired but usually have identical right and left sides (ie. nose)

• Dorsal hollow nerve cord – runs along the back in the median plane- cord develops into the brain and spinal cord

Human Body Plan

• Notochord (back string) and vertebrae – rod in embryo deep to spinal cord

- quickly replaced by the vertebrae,

- some persists as cores of the discs between the vertebrae

• Segmentation – repeating units of similar structure

- ribs, muscles between ribs, nerves, vertebral column

• Pharyngeal pouches – correspond to clefts between gills of fish

- gives rise to some structures in the head and neck (auditory tube, middle ear, thymus, parathyroid and thyroid glands)

Levels of Organization• Chemical Cellular Tissue Organ Organ System Organism

• Chemical Level: atoms

• Cellular Level: smallest unit of life

• Tissue Level: group of similar cells that perform a common function • Organ Level: group of 2 or more tissue types that together perform complex

physiological processes • Organ System Level: various organs with similar or related functions that work

together to accomplish a common purpose

• Organismal Level- result of all simpler levels working together to sustain life

Homeostasis (homeo, unchanging + stasis, standing)Failure of maintaining homeostasis - Disease

Chemical Level - Composition of the Body

Hydrogen62%

Oxygen26%

Carbon10%

Nitrogen1.5%

Other Elements:

Elemental compositionof the human body

CalciumPhosphorusPotassiumSodiumSulfurChlorineMagnesiumIronIodineTrace elements

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

Water67%

Molecular compositionof the human body

Proteins20%

Carbohydrates3%

Lipids10%

LE 1-3

OrganismLevel

Organ System Level

CardiovascularEndocrine

NervousMuscular

Skeletal

Integumentary

LymphaticRespiratory

Digestive

Urinary

Reproductive

The heart

OrganLevel

Cardiacmuscletissue

Tissue Level

Heart muscle cell

Atoms incombination

Protein filaments

Cellular Level

Complex proteinmolecule

Chemical orMolecular Levels

Levels of Organization

LE 1-4

Life• Responsiveness - irritability and adaptability

• Growth and Differentiation - size increase and specialization

• Reproduction - new generations

• Movement - internal (transport of nutrients) or external

• Metabolism: complex chemical reactions to provide energy- catabolism: breakdown of complex molecules- anabolism: synthesis of complex molecules

• Metabolism requires absorption of materials to provide energy

- respiration: absorption, transport, and use of O2 by cells- excretion: elimination of waste products

• Humans- Digestion and CV system (internal transport system)

Overview of the Human Organ Systems

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

Protection from environmentalhazards; temperature control

Locomotion, support, heatproduction

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

Directing long-term changesin the activities of other organ systems

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

Skeletalsystem

Muscularsystem

Nervoussystem

Endocrine system

Cardiovascularsystem

Integumentary system

LE 1-5_2

Defense against infection anddisease

Reproductivesystem

Delivery of air to sites wheregas exchange can occur betweenthe 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

Lymphoidsystem

Respiratorysystem

Digestivesystem

Urinarysystem

Epidermis &associated glands

Hair

Fingernail

Protects against environmental hazards;helps control body temperature

The Integumentary System

Supportingbones (hip)

Provides support; protects tissues;stores minerals; forms blood cells

The Skeletal System

Skull

Lower limbbones

Upper limbbones

Supporting bones(scapula and clavicle)

Sternum

Vertebrae

Ribs

Sacrum

LE 1-6 a,b

Directs immediate responses to stimuli; usually bycoordinating the activities of other organ systems

The Nervous System

Peripheralnerves

Spinalcord

Brain

Allows for locomotion; provides support; produces heat

The Muscular System

Axialmuscles

Appendicularmuscles

LE 1-6 c,d

Directs long-term changes in activities of other organ systems

The Endocrine System

Ovary infemale

Thyroidgland

Pituitary gland

Pancreas

Testis in male

Suprarenalgland

Parathyroid gland

Pineal gland

Thymus

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

The Cardiovascular System

Capillaries

Heart

Vein

Artery

LE 1-6 e,f

LE 1-6 g,h

Defends against infection and disease;Returns tissue fluid to the bloodstream

The Lymphoid System

Spleen

Thymus

Lymphatic vessel

Lymph nodes

Delivers air to sites where gas exchange can occurbetween the air and circulating blood

The Respiratory System

Nasal cavity Sinus

Larynx

BronchiLung

PharynxTrachea

Diaphragm

LE 1-6 i,j

Processes food and absorbs nutrients

The Digestive System

PharynxSalivary gland

PancreasStomach

Small intestine Large intestine

Liver

Gallbladder

Esophagus

Anus

Eliminates excess water, salts, and waste products

The Urinary System

Urinarybladder

Kidney

Ureter

Urethra

LE 1-6 k,l

Produces sex cells and hormones

The Male Reproductive System

Urethra

Prostate gland

Seminal gland

Ductus deferens

Epididymis

Testis

Penis

Scrotum

Produces sex cells and hormones; supports embryonicdevelopment from fertilization to birth

The Female Reproductive System

Mammarygland

Uterinetube

Ovary

Uterus

Vagina

Externalgenitalia

Superficial Anatomy

• Anatomical Position - supine or prone

• Anatomical Regions

• Abdominopelvic quadrants and abdominopelvic regions

Anatomical Landmarks

Auris orear (otic)

Thoracis orthorax, chest(thoracic)

Cervicis or neck (cervical)

Bucca orcheek (buccal)

Oculus oreye (orbital or ocular)

Nasus or nose (nasal)

Mamma or breast(mammary) Trunk

Abdomen(abdominal)

Umbilicusor navel(umbilical)

Frons orforehead (frontal)

Craniumor skull

(cranial)

Faciesor face(facial)

Cephalonor head

(cephalic)

Oris or mouth (oral)

Mentis or chin(mental)

Brachiumor arm

(brachial)

Axilla or armpit(axillary)

Antecubitisor front of

elbow(antecubital) LE 1-8a

Pelvis(pelvic)

Antebrachiumor forearm

(antebrachial)

Pubis(pubic)

Inguenor groin(inguinal)

Manusor hand(manual)

Femur orthigh (femoral)

Pesor foot(pedal)

Carpusor wrist (carpal)

Patellaor kneecap

(patellar)

Digits (phalanges)or fingers (digital

or phalangeal)

Crus orleg (crural)

Palmaor palm

(palmar)

Pollexor thumb

Tarsus orankle

tarsal)

Digits (phalanges)or toes (digital or

phalangeal)Hallux orgreat toe

LE 1-8a

LE 1-8b_1

Shoulder(acromial)

Upperlimb

Cervicis orneck (cervical)

Cephalon orhead (cephalic)

Dorsum orback

(dorsal)

Olecranonor back

of elbow(olecranal)

Lumbusor loin

(lumbar)

LE 1-8b_2

Planta orsole of foot (plantar)

Lowerlimb

Gluteusor buttock

(gluteal)

Popliteus orback of knee

(popliteal)

Sura orcalf (sural)

Calcaneus orheel of foot(calcaneal)

Abdominopelvic Region

• To facilitate its study, the abdominopelvic region can be divided into different regions and quadrants

• There are four quadrants and nine regions

- provides clinicians a useful frame of reference

Abdominopelvic Quadrants

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,and portions of largeintestine, left ureter, andreproductive organs (leftovary in female and left spermatic cord in male)

Abdominopelvic Regions

Lefthypochondriacregion

Left lumbarregion

Left inguinalregion

Righthypochondriac

region

Right lumbarregion

Right inguinalregion

Epigastricregion

Hypogastricregion

Umbilicalregion

LE 1-9b

• R. Hypochondriac - right, upper 1/3; gallbladder, liver, r. kidney

• Epigastric - Upper, central 1/3; liver, stomach, pancreas, duodenum

• L. Hypochondriac - left, upper 1/3; spleen, colon, liver, l. kidney, small intestine

• R. Lumbar - right, lateral 1/3; cecum, ascending colon, liver, r. kidney, small intestine

• Umbilical - center; umbilicus (navel) is located here; jejunum, ileum, duodenum, colon, kidneys, major abdominal vessels

• L. Lumbar - left, lateral 1/3; descending colon, l. kidney, small intestine

• R. Iliac (inguinal) - right, lower 1/3; appendix, cecum, small intestine

• Hypogastric (pubic) - lower, center 1/3; urinary bladder, small intestine, sigmoid colon, female reproductive organs

• L. Iliac (inguinal) - left, lower 1/3; small intestine, descending colon, sigmoid colon

Superficial anatomical landmarks and underlying organs

Urinarybladder

Small intestine

Spleen

Stomach

Large intestine

Liver

Gallbladder

Appendix

LE 1-9c

Directional Terms

Cranial

Posterioror dorsal

Anterioror ventral

Proximal

Left

MedialLateral

Right

Proximal

Distal

Caudal

DistalLE 1-10

Anatomical Directions

Sectional Anatomy

• Planes – any slice through a 3 dimensional object can be described through 3 sectional planes- sagittal, transverse, frontal (coronal)

• Serial reconstruction – a series of sections at small intervals in one sectional plane

• Body cavities – vital organs are suspended in these internal chambers to provide protection

Visible Human Projecthttp://www.nlm.nih.gov/research/visible/visible_human.html

Planes of Section

Transverse plane

Frontal plane Sagittal plane

LE 1-11

Sectional Anatomy‘Planes and Sections’

Dorsal Body Cavity

• Cranial Cavity – encases the brain

• Vertebral Cavity – runs through the vertebral column encloses the SC

Ventral Body Cavity or coelom – contains the viscera

2 major divisions:

• Thoracic Cavity- enclosed by the chest wall

• Abdominopelvic Cavity- enclosed by the abdominal wall and pelvis

ThoracicCavity

(b) Anterior view

CranialCavity

VertebralCavity

Superior mediastinum

Mediastinum withpericardial cavity

Pleural Cavity

Diaphargm

Abdominal Cavity

PelvicCavity

Ven

tral Bod

y Cavity

Body Cavities

LE 1-14

Provides protection;allows organ movement;lining prevents friction

separated bydiaphragm into

Surrounded by chestwall and diaphragm

subdivided into

Surroundsright lung

also contains

Contains the trachea,esophagus, andmajor vessels

Surroundsleft lung

Surrounds heart

Contains theperitoneal cavity

Includes the

Contains manydigestive glandsand organs

Contains urinarybladder, reproductive organs, last portionof digestive tract

Serous Cavities• Serous cavity – narrow fluid-filled space lined by a serous

membrane (serosa) - Pleura- Pericardium- Peritoneum

• Parietal serosa – pleura covers the opposing mediastinal surface and inner body wall; pericardium is continuous with the viseral serosa; peritoneum lines the body wall

• Visceral serosa – covers the visceral organs

• Serous Fluid – watery lubricant secreted by both serous membranes to minimize friction between organs and cavity walls

• Mesenteries – organs (stomach, small intestine, parts of large intestine) are suspended by double sheets of peritoneum to provide support and stability with limited movement

Serous Cavities

Abdominopelviccavity

Diaphragm

Air space

Pelvic cavity

Abdominalcavity

Sternum

Peritonealcavity

Balloon

Heart inpericardial

cavity

Pleuralcavity

Pericardialcavity

Thoraciccavity

Visceralpericardium

Heart Pericardialcavity

Parietalpericardium

RightlungLeft

lungRightlung

Leftlung

Mediastinum

Pleura

Pleural cavity

Spinal cord

Diaphragm

Pleuralcavity

Pericardialcavity

Pelvic cavity

Abdominalcavity

LE 1-13

Clinical Terms

• CT, CAT (computerized [axial] tomography)

• Diagnosis and prognosis

• Disease

• MRI (magnetic resonance imaging)

• Pathology

• Radiologist

• Ultrasound

• X-rays and radiodensity (air, fat, liver, blood, muscle, bone)

X-Ray

Stomach

Small intestine

LE 1-15a

Barium-contrast X-ray

CT Scan

Right kidneyVertebra

Spleen

Aorta

Left kidney

Stomach

Liver

Rib

Vertebra Spleen

Aorta

Left kidney

Stomach

Liver

Vertebra

Spleen

Kidney

StomachLiver

LE 1-16

MRI

Kidney

StomachLiver

Kidney

Ultrasound - echogram

Spiral CT

Arteries ofthe heart

Heart

Heart Firstrib

Sternum

Aorticarch

Vertebralcolumn

RightscapulaAorta

LE 1-17

Digital Subtraction Angiography (DSA)