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. At its cervical end it is partly covered by the cleido-occipitalis.
Origin and insertion
- In the neck: wing of the atlas (ala atlantis).
- At the shoulder: distal part of the spine of the scapula and fascia of the shoulder region.
Action
Advances the thoracic limb. With the limb fixed, bends the neck to the same side.
Clinical relevance
Together with the brachiocephalicus it covers the superficial cervical (prescapular) lymph nodes, which are palpated cranial to the shoulder. Their enlargement is a clinical examination finding, for example in the lymphoma of enzootic bovine leukosis.