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
General Concepts/Directional Descriptors/Surface Regions
Histology
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 =
cranial
caudal
ventral
dorsal
dorsal =
ventral =
superior
inferior
posterior
anterior
superior =
inferior =
dorsal
ventral
cranial
caudal
cranial =
caudal =
anterior
posterior
superior
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
lower right
upper left
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
Right Lumbar
Right Inguinal or Iliac
Epigastric
Umbilical
Hypogastric
Left hypochondriac
Left Lumbar
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
Femoral Triangle
inguinal ligament
adductor longus
sartorius
Histology – the study of tissues
Objectives
what are the diagnostic characteristics of each of the four main types of tissues
what are the diagnostic characteristics of each of the subtypes of tissues
be able to give examples of each tissue type
are organs made of one or more tissues?
Tissues – 4 basic types
epithelial – forms internal or external linings of organs and
glands, specialized for lubrication, resisting abrasion, waterproofing, absorption, and/or secretion; rests on basement
membrane; basal to apical or luminal polarity; one free surface;
cellularity; specialized cell junctions including desmosomes or tight
junctions; rapid regeneration; nourishment by diffusion; no intrinsic
vascularization or innervation
connective – acellularity; extracellular matrix>>cells; provides
structure and/or substrate for blood vessels, nerves, lymphatics,
and glands; extracellular matrix or ground substance = water,
dissolved or precipitated salts, proteins, and carbohydrates
muscular – electrochemically excitatory and contractile
nervous - electrochemically excitatory and conductive
Epithelium (pl. epithelia)
simple squamous
flat, single layered
endothelium of blood vessels
stratified squamous
multilayered with basal germinal layer
epidermis of skin
simple cuboidal
glands and their ducts
stratified cuboidal
gall bladder, sexual ducts
simple columnar
cells tall, parallel
brush border or microvilli
endothelium of intestines
pseudostratified columnar
cells tall, not parallel
ciliated
endothelium of trachea
transitional
urinary bladder
glands – both excretory and secretory
endocrine – ductless
exocrine – possess ducts
shape: tubular, alveolar, simple, complex
Non-binding Connective Tissue
blood/lymph – formed elements = cellular, plasma = water, dissolved
salts, nutrients, nitrogenous waste, CO2, albumin, fibrinogen, globulins
Binding Connective Tissue
loose connective tissue – little protein in extracellular matrix
areolar – collagen, forms interstitia
adipose – lipid droplets, fat
reticular – reticulin, net or filter structure of lymph organs
dense connective tissue – much protein in extracellular matrix
regular – parallel collagen fibers, e.g., tendons
irregular – nonparallel collagen fibers, e.g., dermis of skin
elastic – elastin, rebounds after deformation, e.g., arteries
cartilage – extracellular matrix with glycosaminoglycans, chondroitin
sulfate, hyaluronic acid; chondrocytes reside in lacunae; interstitial and
appositional growth
hyaline – collagen, most common type in skeletal system
elastic – elastin, e.g., pinna of ear, epiglottis
fibrous – fibrin, very tough joints, e.g., intervertebral discs
bone – highly vascularized extracellular matrix of precipitated collagen
and apatite [Ca3(PO4)2]; osteocytes reside in lacunae; appositional
growth only
Muscular Tissue – Ca++ and ATP dependent contraction; thin filaments –
actin, troponin, meromyosin; thick filaments – myosin
smooth muscle – spindle shaped cells, mononucleate, in walls of organs (e.g.,
digestive tract, blood vessels, skin), respond to hormones, stretch, and
innervation by autonomic nervous system
striated muscle – myofilaments bundled into myofibrils forming ‘striated’
sarcomeres (alternating interdigitating bands of thick and thin filaments),
juxtaposed to sarcoplasmic reticulum (ER sequesters Ca++) and transverse
tubules (invaginations of sarcolemma); numerous mitochondria
skeletal striated muscle – giant multinucleate linear cells of voluntary skeletal
muscular system, syncytium, every cell innervated with motor endplate,
responds to neurotransmitter acetylcholine; denervation results in atrophy
cardiac striated muscle – myocardium of heart; branching cells joined at
intercalated discs; syncytium but few nuclei; intercalated discs possess gap
junctions (electrical connectivity) and desmosomes; cells depolarize
spontaneously and wave of contraction passes from cell to cell; rate modulated
by hormones and autonomic innervation
Striated Muscle – myofilaments bundled into myofibrils forming ‘striated’
sarcomeres (alternating interdigitating bands of thick and thin filaments),
juxtaposed to sarcoplasmic reticulum (ER sequesters Ca++) and transverse
tubules (invaginations of sarcolemma); numerous mitochondria
Nervous Tissue
neuroglia or glial cells – structural, supportive, insulating
neurons – excitatory; cell body or ‘neuron’; cell processes
are axons and dendrites; slow transport of neurotransmitters
from neuron to presynaptic vesicles of axon; membrane
depolarization causes release of neurotransmitters into
synapse which are bound by receptors of postsynaptic
dendrites; neurotransmitters may be excitatory, inhibitory, or
modifying to membrane depolarization of postsynaptic
neuron
Neurons – excitatory; cell body or ‘neuron’; cell processes are axons and
dendrites; slow transport of neurotransmitters from neuron to presynaptic
vesicles of axon; membrane depolarization causes release of
neurotransmitters into synapse which are bound by receptors of
postsynaptic dendrites; neurotransmitters may be excitatory, inhibitory, or
modifying to membrane depolarization of postsynaptic neuron