Extrinsic Muscles of the Thoracic Limb

Question 0

Deep pectoral

Answer 0

O: sternum
I: greater and lesser tubercles of humerus
A: adduct thoracic limb and pull it caudally

Question 1

Superficial Pectoral

Answer 1

O: cranial sternum
I: crest of greater tubercle and cranial border of humerus
A: adduct thoracic limb

Question 2

brachiocephalicus

Answer 2

cranial attachment: dorsal neck and mastoid process of skull
caudal attachment: distal cranial humerus
action: not bearing weight - pull thoracic limb cranially
and/or depress and pull head and neck laterally

Question 3

omotransversarius

Answer 3

O: wing of atlas
I: distal spine of scapula
A: (same as brachiocephalicus) not bearing weight - pull thoracic limb cranially
and/or depress and pull head and neck laterally

Question 4

trapezius

Answer 4

O: cervical part - dorsal neck
thoracic part - dorsal thorax
I: spine of scapula
A: elevate thoracic limb

Question 5

rhomboideus

Answer 5

O: capital part (carnivores) - occipital bone
cervical part - dorsal neck
thoracic part - dorsal thorax
I: dorsal border of scapula and/or scapular cartilage
A: elevate thoracic limb and depress scapula to trunk

Question 6

serratus ventralis

Answer 6

O: cervical part - cervical vertebrae
thoracic part - thoracic wall [ribs]
I: serrated face of scapula
A: support and/or elevate trunk

Question 7

latissimus dorsi

Answer 7

O: thoracolumbar fascia
I: teres major tuberosity of humerus
A: draw thoracic limb caudally
not bearing weight - flex humeral joint
bearing weight - extend humeral joint