Overview
A flat, elongated muscle of the neck lying between the trapezius (dorsally) and the brachiocephalicus (ventrally). It is one of the muscles that attach the thoracic limb to the trunk.
Origin
Distal part of the spine of the scapula and acromion.
Insertion
Wing of the atlas (caudal border of the transverse process).
Action
Advances the thoracic limb. With the limb fixed, bends the neck to the same side.
Innervation
Accessory nerve (n. accessorius).
Clinical relevance
Together with the brachiocephalicus it covers the superficial cervical lymph nodes, which are palpated cranial to the scapula.