A&P Practical: Key Terms & Definitions for Biology

dorsal

toward the back

ventral

toward the belly

cranial

toward the head

caudal

toward the tail

rostral

toward the nose

palmar

bottom surface of forelimb digits

plantar

bottom surface of hindlimb digits

medial

towards median plane

lateral

away from median plane

proximal

Closer to the point of attachment

distal

away from the point of attachment

deep

Away from the body surface; more internal

superficial

near the surface

occipital bone

single bone that forms the "base" of the skull. houses foramen magnum and condyles

occipital condyle

forms a joint with the atlas

nuchal crest

Part of the skull where the neck muscles attach

foramen magnum

large opening where the spinal cord exits the skull

temporal bone

paired bones that form the sides of the head in the ear region, forms portion of zygomatic arch. below parietal bone. forms TMJ

tympanic bullae

egg shaped swelling on the ventral surface, contains middle ear structures

zygomatic process (temporal)

a projection of the temporal bone that forms part of the zygoma

external auditory meatus

opening that leads to the middle and inner ear cavities

zygomatic bone

cheekbones, paired, forms portion of eye orbit and portion of zygomatic arch

lacrimal bone

small fragile bone making up part of the front inner walls of each eye socket and providing room for the passage of the lacrimal ducts

nasolacrimal canal

allows passage of lacrimal duct

parietal bone

either of two skull bones between the frontal and occipital bones and forming the top and sides of the cranium

sagittal crest

A ridge of bone that runs down the middle of the cranium like a short Mohawk. This serves as the attachment for the large temporal muscles, indicating strong chewing.

frontal bone

paired, forms forehead part of skull, contains large frontal sinuses. rostral to temporal

ethmoid bone

forms part of the posterior portion of the nose, the orbit, and the floor of the cranium

nasal bone

paired, forms the bridge of nose, dorsal part of nasal cavity

maxillary bone

paired, make up most of upper jaw, house upper canine, upper premolar, and molar teeth. forms portion of hard palate

infraorbital foramen

opening under the orbit carrying the infraorbital nerves and blood vessels the the nasal region

palatine bone

paired, caudal edge of hard palate, very small

mandible bone

lower jaw, paired, united by symphysis in dogs, cats, cattle. solid bone in adult horses and swine

ramus

vertical part at caudal end of mandible that forms the tmj with the temporal bone. jaw muscles attach here

mandibular synthesis

joins both sides of mandible bone

condylar process

the condyle of the ramus of the mandible that articulates with the skull

coronoid process mandible

insertion of temporalis

mental foramen

mandible hole

phalanges

digits, numbered 1-5 medial to lateral. proximal, middle, and distal sections

proximal phalanx

P1, long pastern

middle phalanx

P2, short pastern

distal phalanx

P3, coffin bone

ruminant phalanges

3 and 4 support weight, 2 and 5 are dewclaws

horse phalanges

Horses have one digit on each limb composed of three phalanges and three sesamoid bones

clavicle

collar bone, exclusive to cats. embedded in muscle

scapula

shoulder blade. has spine, glenoid cavity, neck

spine

ridge that projects laterally. shoulder muscles attach here

acromion

extension of the scapula, which forms the high point of the shoulder, absent in horses

glenoid fossa

scapula cavity where humerus fits, socket part of ball and socket

humerus

upper arm bone, has head, greater tubercle, condyles (trochlea and capitulum), epicondyles, and olecranon fossa

humerus head

rounded section of the humerus that articulates with the glenoid cavity of the scapula

greater tubercle

tuberosity, top of humerus, site of many muscle attachments, point of shoulder

deltoid tuberosity

The ridge on the anterior surface of the humerus that allows for attachment of the deltoid muscle. lateral aspect

lateral epicondyle

humerus

medial epicondyle

humerus

olecranon fossa

Indentation above the condyles of the humerus, depression of distal humerus, receives olecranon on extension

supracondylar foramen

hole on medial surface of humerus in cats

radius

main weight bearing bone of forearm, starts laterally and courses medially. has head and styloid process

radius head

proximal aspect with concave articular surface that articulates with the humerus

styloid process

distal aspect on radius that articulates with radial carpal bone

ulna

long thin bone of forearm, starts medially and courses laterally. has olecranon fossa, trochlear notch, anconial process, coronoid process, radial notch, styloid process

olecranon

proximal aspect of ulna, point of elbow

anconceal process

beak shaped at proximal end of trochlear notch, resides into olecranon fossa

trochlear notch

semilunar notch, wraps around trochlea of humeral condyle and makes joint tight and secure

carpus

wrist, consists of two parallel rows of short bones

radial carpal bone

largest, most medial, articulate with radius

ulnar carpal bone

located laterally, articulates with ulna

accessory carpal bone

on palmar aspect of carpus, articulates with ulnar carpal bone, only carpal bone with direct muscle attachements

carpal row

1-4 medial to lateral

cervical vertebrae

7

atlas

C1 . no ventral body but consists of a bony ring that the spinal chord passes through, two large transverse process wings. articulates with occipital condyles

axis

C2 large thick spinous process that overlaps. thick bladelike spinous process that overlaps. has peg like dens on its cranial end that tuck into C1

dens

on axis, tuck into C1

thoracic vertebrae

13

spinous process

projects dorsally, allows for flexion of trunk

lumbar vertebrae

7

transverse process

projects laterally. landmark for paravertebral blocks in cattle

sacral vertebrae

3 fused

sacrum

three vertebrae fused together that get smaller as move caudally, forms joint with ilium

dorsal sacral foramina

foramina found on the posterior side of the sacrum, lateral to the midline

ventral sacral foramina

Foramina found on the anterior side of the sacrum, lateral to the midine

coccygeal vertebrae

20-25

true ribs

firs nine pair of ribs, attach individually to sternum

false ribs

next three pairs, attach to sternum via costal cartilage

floating ribs

final pair, no attachment to sternum

costal cartilage

the cartilages that connect the sternum and the ends of the ribs

costal arch

curved structure formed by the costal cartilages of the false ribs

sternum

breastbone made up of sternebrae, lies along ventral middle

manubrium

first sternebrae, cranial part

xiphoid process

last sternebrae, cartilage extends off caudal end, palpable

thoracic inlet

Cranial entrance into the chest cavity

thoracic outlet

Exit of the chest

ilium

most cranial bone, wing shaped lateral surface, palpable. medial articulates with sacrum. cranial margin of acetabulum

tuber coxae

point of hip, wing of ilium

acetabulum

hip joint, site of attachment of the femoral head

ischium

most caudal bone, caudal to obturator foramen, caudal aspect of acetabulum

ischiatic tuberosity

thick caudal protuberance on ischium

pelvic symphysis

two hales of pelvis are joined ventrally by a cartilaginous joint, formed by ischium and pubis bones

obturator foramen

two large holes on either side of the pelvic symphysis that help reduce the weight of the pelvis bones

femur

thigh bone, heaviest in body. has head, greater trochanter, condyles, epicondyles, trochlea