INTRINSIC MUSCLES OF THE THORACIC LIMB (AND OTHER STRUCTURES) Muscle Origin Insertion Deep Pectoral he ventral part T of the sternum and the fibrous raphe between fellow muscles; the deep abdominal fascia in the region of the xiphoid cartilage (the caudal end of the sternum). he major portion C T audal pectoral partly muscular, nerves (C8, T1) partly tendinous on the lesser tubercle of the humerus; an aponeurosis to the greater tubercle and its crest; the caudal part to the medial brachial fascia. hen the limb is W advanced and fixed: to pull the trunk cranially and to extend the shoulder joint. When the limb is not supporting weight: to draw the limb caudally and flex the shoulder joint. To adduct the limb. Superficial Pectoral The first two sternebrae and usually a part of the third; the fibrous raphe between adjacent muscles. he whole crest T of the greater tubercle of the humerus. ranial pectoral C nerves (C7, C8) o adduct the T Descending- limb when it is not smaller and bearing weight or superficial to: to prevent the Transverse- limb from being Arrises from first abducted when 2-3 sternebrae bearing weight Brachiocephalicus insert at the humerus, the dorsal cervical raphe, and the mastoid process of the temporal bone ccessory nerve A and ventral branches of cervical spinal nerves. o advance the T limb; to extend the shoulder joint and draw the neck and head to the side lavicular tendon C and the distal end of the cranial surface of the humerus. Insertion: Dorsal surface of the neck Innervation Action NOTES he T brachiocephalicu s muscle has two main sections: the cleidobrachialis and the cleidocephalicus. he T cleidocephalicus is further divided into the pars cervicalis and the pars mastoideus Omotransversarius It is straplike and extends from the distal end of the spine of the scapula to the atlas. It is related to the deep cervical fascia medially. Its caudal part is subcutaneous, but cranially it is covered by the cervical part of the cleidocephalicus. Trapezius It extends from the atlas to the spine of the scapula, with its origin on the transverse process of the atlas and its insertion in the distal end of the spine of the scapula. he median T he spine of the T raphe of the neck scapula. and the supraspinous ligament from the level of the third cervical vertebra to the level of the ninth thoracic Accessory nerve. T o advance the limb or flex the neck laterally Accessory nerve o elevate and T abduct the forelimb vertebra Rhomboideus he nuchal crest T of the occipital bone; the median fibrous raphe of the neck; the spinous processes of the first seven thoracic vertebrae. he dorsal border T and adjacent surfaces of the scapula. entral branches V of cervical and thoracic spinal nerves. o elevate the T -Capitis, cervicis, forelimb and draw thoracis the scapula against the trunk. Latissimus Dorsi he T thoracolumbar fascia from the spinous processes of the lumbar and the last seven or eight thoracic vertebrae; a muscular attachment to the last two or three ribs he teres major T tuberosity of the humerus and the teres major tendon. horacodorsal T nerve (C7, C8, T1). o draw the free T limb caudally as in digging; to flex the shoulder joint. Serratus Ventralis he transverse T processes of the last five cervical vertebrae and the first seven or eight ribs ventral he dorsomedial T third of the scapula (serrated face) entral branches V of cervical spinal nerves and the long thoracic nerve (C7) o support the T trunk and depress the scapula. - Cervicis and thoracis to their middle. Sternocephalicus he first T sternebra or manubrium. Sternohyoideus Sternothyroideus he mastoid part T of the temporal bone and the nuchal crest of the occipital bone ccessory nerve A and ventral branches of cervical spinal nerves. o draw the head T and neck to the side. he first T he basihyoid T sternebra and the bone first costal cartilage. entral branches V of cervical spinal nerves. o pull the tongue T and larynx caudally The first costal c artilage entral branches V of cervical spinal nerves. Same as the s ternohyoideus— to draw the larynx and tongue caudally. he caudolateral T surface of the thyroid cartilage.
