Digastric muscle

By Dr. Vishaal Bhat on Saturday, July 5, 2008 with 0 comments

a. Two bodies: anterior and posterior

b. Origin:

-anterior belly: intermediate tendon that separates the two

-posterior belly: mastoid notch


-anterior belly: digastric fossa below mental spine

-posterior belly: intermediate tendon that separates the two

d. Action:

-with mandible fixed, anterior draws hyoid bone forward and posterior draws hyoid bond backward. Together, they elevate hyoid bone in swallowing.

-with hyoid bone fixed, contracting unilaterally, they draw mandible to one side. Contracting bilaterally, they retract and depress the mandible.

-V3 innervates all muscles of mastication and the tensors (tensor veli palatini and tensor tympani). Levator veli palatini is innervated by the vagus nerve.

-anterior belly of digastric is innervated by mylohyoid nerve (a branch of V), and the posterior belly is innervated by the facial nerve (VII).

-genioglossus muscle is innervated by CN XII (hyopoglossal nerve).

Category: Anatomy Notes



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