Why dissect?

…because personal discovery is an important aspect of learning

Why cats?

…because homology allows us to use cats as model organisms

(and we can’t dissect human cadavers)

“homology” defined:

inheritance from common ancestor regardless of similarity in form or function

Advantage of using non-human organisms in addition to human models

…realism

…individual variation due to:

ontogeny (life stage)

polymorphism (genetic variation)

history (“stuff” happens)

Organization of Course

Systemic vs Regional Anatomy

Histology

General Concepts/Directional Descriptors/Surface Regions

Organ Systems

Cells

Tissues – collections of large numbers of similar types of cells

Organs – functional structures always composed of multiple tissue

types

Organ Systems – collections of organs that synergistically serve a

common function, and are typically of similar developmental origins

Organ Systems

Skeletal

[Skeleto]Muscular

Integumentary

Digestive

Respiratory

Circulatory

Cardiovascular

Lymphatic

Urogenital

Excretory or Urinary

Reproductive

Endocrine

Nervous

Anatomical Relationships

Objectives

be able to demonstrate and describe

anatomical position

the three orthogonal planes

anatomical directions

Fluent use of terms

Anatomical Position

human

standing erect, facing forward, arms to body, palms forward, thumbs to side, legs together, toes forward

cat

four paws on ground, torso horizontal

right vs left – always the subject’s

Orthogonal Planes – lie at right angles to one another

sagittal – vertical, divides world into right and left

midsagittal – passes thru midline of body

parasagittal – to side or outside body

frontal or coronal – vertical, divides world into anterior (in front) and posterior (behind)

transverse – horizontal, divides world into superior (above) and inferior (below)

- do not confuse with transverse section

Oblique Planes – infinite in number

Opposite Anatomical Directions

anterior / posterior – forward, behind (separated by coronal plane)

dorsal / ventral – back (i.e., spinal) side, belly side

superior / inferior – above, below (separated by transverse plane)

medial / lateral – towards midline, towards side (sep’d by sagittal plane)

cranial or cephalad / caudal – towards head, towards tail

proximal / distal – towards beginning, towards end

superficial / deep – towards surface, underneath

also: palmar – anterior of manus plantar – inferior of pes

Note: all terms may end in “-ad” e.g., anteriad, dorsad, laterad, etc.

Cat Human

anterior =

posterior =

dorsal =

ventral =

superior =

inferior =

cranial =

caudal =

Cat Human

anterior = cranial ventral

posterior =

dorsal =

ventral =

superior =

inferior =

cranial =

caudal =

Cat Human

anterior = cranial ventral

posterior = caudal dorsal

dorsal =

ventral =

superior =

inferior =

cranial =

caudal =

Cat Human

anterior = cranial ventral

posterior = caudal dorsal

dorsal = superior posterior

ventral =

superior =

inferior =

cranial =

caudal =

Cat Human

anterior = cranial ventral

posterior = caudal dorsal

dorsal = superior posterior

ventral = inferior anterior

superior =

inferior =

cranial =

caudal =

Cat Human

anterior = cranial ventral

posterior = caudal dorsal

dorsal = superior posterior

ventral = inferior anterior

superior = dorsal cranial

inferior =

cranial =

caudal =

Cat Human

anterior = cranial ventral

posterior = caudal dorsal

dorsal = superior posterior

ventral = inferior anterior

superior = dorsal cranial

inferior = ventral caudal

cranial =

caudal =

Cat Human

anterior = cranial ventral

posterior = caudal dorsal

dorsal = superior posterior

ventral = inferior anterior

superior = dorsal cranial

inferior = ventral caudal

cranial = anterior superior

caudal =

Cat Human

anterior = cranial ventral

posterior = caudal dorsal

dorsal = superior posterior

ventral = inferior anterior

superior = dorsal cranial

inferior = ventral caudal

cranial = anterior superior

caudal = posterior inferior

Regional anatomy, surface topography and landmarks

Objectives

be able to relate surface topography and landmarks to underlying organs

how are the body cavities defined

what are their contents

Body Cavities

dorsal body cavity

cranial and vertebral cavities

ventral body cavity (divisions of the coelom)

thoracic cavity

2 pleural cavities (separated by mediastinum)

pericardial cavity (within mediastinum)

abdominal cavity – separated from thoracic cavity by respiratory diaphragm

pelvic cavity – separated from abdominal cavity by pelvic “brim” or “inlet”

Surface Regional Anatomy: Cranial, cephalic – head

nasal – area of nose

orbital – area of eye sockets

palpebral - eyelids

supraorbital – brow ridge

infraorbital – below eyes

frontal - forehead

mental - chin

oral - mouth

labial - lips

philtrum – depression in superior labium

buccal – soft cheek

zygomatic – bony cheek

temporal – depression posterolateral to orbit

auricular – area of ear

occipital or occiput – back of head

mastoid – bony protrusion inferoposterior to auricular region

mandibular - jaw

mandibular angle – inferoposterior margin of jaw

Surface Regional Anatomy: cervical – neck, separated from cranial region by inferior margin of mandible and superior nuchal line

Nuchal region – muscular back of neck, superior belly of trapezius muscle

Posterior cervical triangle – defined by sternocleidomastoid (SCM) muscle, superior belly of trapezius muscle, and clavicle

Anterior cervical triangle – defined by sternocleidomastoid (SCM) muscle, inferior margin of mandible, and midsagittal plane

Submandibular triangle – immediately inferior to mandible

Carotid triangle – immediately anterior to SCM

Laryngeal eminence – “Adam’s apple”

Thyroid region – area surrounding laryngeal eminence

Suprasternal or jugular notch – depression superior to sternum and between right and left SCM

Surface Regional Anatomy: thoracic – chest, separated from cervical region by clavicles, acromion, and spine of seventh cervical vertebra

Pectoral – muscular breast

Scapular – shoulder blade

Axillary - armpit

Sternal – breastbone

Sternal angle – articulation of manubrium and sternal body, at level of 2nd rib, superior margin of heart, and fourth thoracic intervertebral disc

Xiphisternal joint - articulation of sternal body and xiphoid process, at level of inferior margin of heart, and eighth thoracic intervertebral disc

Mammary – glandular breast

Areola - nipple

Midclavicular line – vertical line bisecting clavicle into medial and lateral halves, passes ½ inch medial to areola in males

Midaxillary line - vertical line bisecting axilla

Triangle of auscultation – defined by inferior belly of trapezius muscle, superior margin of latissimus dorsi muscle, and medial margin of scapula

Surface Regional Anatomy: abdominal – all that lies between thorax and hips, anterior and posterior, separated from thoracic region by costal margin

Four abdominal Quadrants – defined by vertical and horizontal lines drawn thru umbilicus

upper right upper left

lower right lower left

Surface Regional Anatomy: abdominal

Nine abdominal regions – like a tick-tack-toe board defined by two vertical midclavicular lines and two horizontal lines drawn from the costal margin and iliac crest laterally

Right hypochondriac Epigastric Left hypochondriac

Right Lumbar Umbilical Left Lumbar

Right Inguinal or Iliac Hypogastric Left Inguinal or Iliac

McBurney’s point - two thirds the distance from the umbilicus to the right anterior superior iliac spine

Surface Regional Anatomy: Pelvic – all that lies

between abdomen and thighs, separated from abdominal

region by iliac crest and inguinal ligament

Gluteal – muscular

Gluteal folds – horizontal

Gluteal cleft – vertical midsagittal

Midsagittal regions, ventral to dorsal:

Pubic – bony

Genital – external genitalia, not bony

Perineal – surrounding anus, not bony

Sacral – superior to gluteal cleft, bony

Surface Regional Anatomy: Upper Extremity

Brachium – arm

Deltoid - proximolateral brachium

Cubitus or cubital – elbow

Olecranon process – bony posterior elbow

Medial epicondyle of humerus – bony medial elbow

Cubital tunnel – ‘funny’ bone!

Antecubital – anterior elbow

Antebrachium – forearm

Carpal – wrist

Pisiform – anteromedial bony landmark of wrist

Manus or manual – hand

Palmar – palm

Dorsum - back (of hand, as used here)

Thenar – fleshy lateral palm

Hypothenar – fleshy medial palm

Digital or digits (numbered I-V lateral to medial)

Pollex or pollical – thumb

Digiti indicis – index finger

Digiti minimi or quinti – “pinky”

Ungual – referring to fingernail

Surface Regional Anatomy: Lower Extremity

Femur or femoral – thigh

Femoral triangle – defined by inguinal ligament, sartorius muscle, and adductor longus muscle

Genu – knee

Patellar – anterior knee or knee cap

Popliteal – posterior knee

Crus or crural – leg (knee to ankle only)

Sura or sural – posterior crus or ‘calf’

Tarsal – ankle

Medial malleolus – bony protuberance of medial ankle

Lateral malleolus - bony protuberance of lateral ankle

Pes or pedal – foot

Calcaneal – heel

Plantar – sole of foot

Dorsum - top of foot

Digital or digits (numbered I-V medial to lateral)

hallux or hallucal – big toe

Digiti minimi or quinti – “the little piggy that went wee-wee-wee all the way home”

Ungual – referring to toenail

sartorius adductor longus

inguinal ligament

Femoral Triangle