CompAnat: Chapter 4

Pectoral girdle

Coracoid, the Collar bone (clavicle, clavicula) and the Shoulder blade (scapula) and joins the forelimb to the trunk.

Stylopodium

Skeleton of the arm

Zeugopodium

Skeleton of the forearm

Autopodium

Skeleton of the manus

basipodium

carpal bones (ossa carpi),

metapodium

metacarpal bones (ossa metacarpi)

acropodium

phalanges (ossa digitorum manus)

Domestic mammal, coracoid process

coracoid is reduced to a cylindrical process (coracoid process, processus coracoideus) fused to the medial side of the scapula.

Clavicle

either absent or a small rudiment embedded in the brachiocephalic muscle,

Man

in contrast to the well-developed functional clavicle

Scapula

triangular in outline and lies flat against the cranial part of the lateral thoracic wall in a cranioventral direction

Acromion

The spine ends with a well-defined prominence

Carnivores and Ruminants

Acromion is close to the ventral angle

Horse and Pig

The acrominion subsides distally

Processus hamatus

This prominence is extended to form a distinct process in the dog

Processus suprahamatus

This prominence is extended to form a distinct process in the cat

Tuber of the spine

present dorsal to its middle in all domestic mammals with the exception of the carnivores

Supratrochlear foramen

 In the dog, the olecranon fossa and the radial fossa communicate through

Supracondylar foramen

In the cat the medial aspect of the distal extremity of the humerus is perforated by the

humerus

has a central function in the movement of the thoracic limb.

Humerus

has a central function in the movement of the thoracic limb.

Humerus

Its surface is characteristically modelled by the attachment of strong muscles and their tendons, which led to the development of prominent bony protuberances and grooves.

Radius, Ulna

The skeleton of the distal part (zeugopodium) of the free appendage of the forelimb consists of two bones

Pronation

if the palm of the hand is turned backward

Pronation

the bones of the forearm are in a crossed over position

Supination

if the palm of the hand is turned forward

Supination

radius and ulna are placed parallel to each other

Horse

distal part of the ulna is completely reduced

Radius

rod-shaped bone that is relatively stronger in ungulates than in carnivores 

Ungulates

radius alone articulates with the humerus

Carnivores

Radius is complemented medially by the ulna

Ulna

very prominent point of the elbow and furnishes insertion to the strong triceps muscle of the forearm.

Olecranon and tuber

extend the ulna beyond the distal extremity of the humerus.

Basipodium, Metapodium, Acropodium

The autopodium consists, from proximal to distal, of three segments:

Carpal bones

Autopodium

Metacarpal bones

Metapodium

Phalanges

Acropodium

Humans and pigs

the original number of eight carpal bones is maintained

Horse

has seven or eight carpal bones, depending on the presence or absence of the first carpal bone

carnivores

radial and intermediate carpal bones are fused, so that the total numbers of carpal bones is reduced to seven, although one or two sesamoid bones can be present.

Ruminants

have six carpal bones, the first carpal bone is missing and the second and third carpal bones are fused.

Metacarpal bones

The original pattern of the skeleton of the metacarpus displays five separate rays

Horse

only Mc III is fully developed and carries the single digit

Slint bones

In horses, only remnants of Mc II and Mc IV survive as the

Carnivores

Two middle metacarpal bones (Mc III and Mc IV) are the longest, Mc II and Mc V are shorter and Mc I is most reduced

Pig

Mc III and IV are well developed

Artiodactyl

In the Pig Mc III and IV are well developed

perissodactyl

In the Horse only Mc III (cannon bone) is fully developed and carries the single digit

Ruminants

Mc III and IV are united on the proximal and middle part to form the large metacarpal bone, the distal extremities articulate separately with the proximal phalanges, Mc V is reduced to become the small metacarpal bone, and Mc I and Mc II are lacking

Proximal Phalanx

phalanx with a proximal extremity (base, basis), a shaft (body, corpus) and a distal extremity (caput); both extremities exhibit articular facets and prominences for ligamentous attachment; 

Middle Phalanx

 shorter, but very similar to the proximal phalanx, 

Distal phalanx

Modified to conform to the hoof or claw that is enclosed within; exhibits an articular (facies articularis), a parietal (facies parietalis) and a solar surface (facies solaris).

Articular, Parietal, Solar

Distal phalanx three bases

antebrachiocarpal joint

hinge joint in the horse, a cochlear joint in ruminants and a ellipsoidal joint in carnivores, where, in addition to the hinge movement

Middle carpal joint

Complex hinge joint

Fetlock, Coffin Join

Hinge joints in phalangeal joints

Pastern Joint

Saddle joint in phalangeal joints

Hinge joint/ginglymus

formed by the humeral condyle with the trochlear notch of the ulna and the radial head

Synarcosis

arrangement of muscles, tendons and fascia

Spheroidal joint

glenoid cavity of the scapula and humeral head