Lecture 4 - Pectoral girdle Flashcards
What part of the skeleton make up the pectoral girdle?
Coracoid, scapula, and clavicle
What part of the skeleton makes up the brachium?
Humerus
What part of the skeleton makes up the ante brachium?
Radius and ulna
What part of the skeleton makes up the carpus?
carpal bones
What part of the skeleton makes up the metacarpus?
metacarpal bones
What part of the skeleton makes up the digits?
Proximal, middle, and distal phalanges
Cingulum
shoulder
Stylopodium
brachium
Zeugopodium
antebrachium
Autopodium
manus
Basipodium
carpus
Metapodium
metacarpus
Acropodium
digit
What animals have complete pectoral girdles?
reptiles, birds, and monotremes
What is the structure of the pectoral girdle in MOST animals?
coracoid is reduced to a coracoid process
What is the clavicle like in cursorial quadrupedal mammals?
reduced or absent , no bony attachment of limb to pelvis
What is different about the scapula in a horse?
Dorsal aspect is extended by cartilage
Spine does not terminate at acromion process
Tuber spinae
What is the tuber spinae?
Thickened middle portion of the spine
What goes through the supracondylar foramen?
Brachial artery and medial nerve
What is different about the humerus of the horse?
Greater tubercle - cranial and caudal portion
Intermediate tubercle
Why is the shoulder joint in domestic animals restricted?
Due to the extensive muscling around the joint
In what way is the shoulder joint in domestic animals restricted?
sagittal excursions
What bony parts are in the glena-humeral joint?
head of humerus, gleaned of scapular
What cartilage structure helps support the gleno-hemeral joint?
labrum
Why does the shoulder joint have to be supported by muscles and tendons?
lacks collaeral ligaments
What can the synovial fuss be confused with?
lesions on the cartilage
What is the brachial plexus formed by?
ventral rami of C6-T2 (variations of C5-T1)
What are the nerves of the BP that go to the extrinsic limb muscles?
Cranial pectoral, long thoracic, thoracodorsal, lateral thoracic, and caudal pectoral
What nerve contributes to the long thoracic?
C7
What muscle does the long thoracic n. innervate?
Serratus ventralis
What nerve contributes to the thoracodorsal n.?
C8
What muscle does the throacodorsal n.?
Latissimus dorsi
What nerve contributes to the lateral thoracic n.?
T1
What muscle does the lateral thoracic n. innervate?
Cutaneous trunci
What nerve contributes to cranial/caudal pectoral n.?
T1
What muscle does cranial/caudal pectoral n. innervate?
Pectoral mm.
What arteries come off the brachiocephalic trunk in the dog?
right subclavian a.
common carotid aa. (off short bicarotid trunk)
What branches off the aorta in dogs?
Brachiocephalic trunk and left subclavian a.
What arteries supply the shoulder?
Superficial cervial a., suprascapular a., and subscapular a.
What do the muscles of the pectoral girdle do?
1) suspend the thorax
2) stabilize the shoulder
3) move the limb
In what directions does the scapula move?
cranial-caudal
dorsal-ventral
rotatory manner
What movement advances the limb?
rotation that moves glenoid cranially
What movement retracts the limb?
rotation that moves glenoid more ventrally
What are the parts of the rhomboideus?
thoracis, cervicis, and capitis
What are the parts of the serrates ventralis?
thoracis and cervicis
What muscle do horses have that dogs don’t?
Subclavius
What are the extrinsic shoulder muscles?
Omotransversarius, trapezius, brachiocephalicus, rhomboideus, latissimus dorsi, pectoralis profundus, subclavius (horse)
Serratus ventralis
What are the muscles of the thorax?
Superficial pectoral m., Deep pectoral m.,
What makes up the synarcosis in the shoulder?
pectoralis profundus and pelvic girdle muscles
What is a synarcosis?
union of parts of the skeleton via muscles
Whats makes the muscular supportive sling present in horses and cattle?
Serratus ventralis and pectoralis profundus
What does this muscular sling do?
Transmit weight of head, neck and cranial part of trunk to forelimbs
Prevent thorax from collapsing
What does the pectoral girdle do in regards to the scapula?
Stabilize it against external forces
What is an external force that harms the scapula?
force of landing after jumping or pouncing can cause displacement or rotation of the scapula
What is a rupture of the serratus ventralis?
severe trama to neck and withers where serratus ventralis attaches
What is the progonosis of a serratus ventralis rupture?
Rarely see a full recovery
Surgery or euthanize
