Extrinsic Muscles of the Thoracic Limb

[Up] [extrinsicmm.] [intrinsicmm.] [arteries] [nerves] [Equine digit]

[image 1] [image 2] [image 3] [image 4]

In this image, the brachiocephalic and trapezius muscles have been transected and reflected.

Muscle A is the omotransversarius muscle; Muscle B is the cervical portion of the serratus ventralis muscle (click on B to see the thoracic portion of this muscle); Muscle C is the rhomboideus muscle (image 4 has a better view of it); D1 and D2 are the reflected cervical and thoracic portions of the trapezius muscle; Muscle E is the latissimus dorsi muscle; Label F is pointing to the spinal accessory nerve (can you see branches of this nerve going to the trapezius muscle, just below the label D1?); and label G is on the superficial cervical lymph nodes, which are surrounded by fat. Which muscles are innervated by the spinal accessory nerve? (answer is below)

The cleidomastoideus and the cleidocervicalis portions of the brachiocephalic muscle, the omotransversarius muscle and the trapezius muscle are innervated by the spinal accessory nerve.