Humerus

The video tutorial covers the anatomy and function of the sternocleidomastoid muscle, a two-headed neck muscle. It discusses the muscle's visibility, innervation by the accessory nerve and cervical plexus, and its origin and insertion points. The tutorial also highlights the neurovascular bundle beneath the muscle and explains how unilateral and bilateral contractions affect head movement and support breathing.

Explain the actions of the sternocleidomastoid muscle during unilateral contraction.

What role does the sternocleidomastoid muscle play in inspiration?