Submandibular Triangle Flashcards
What is the base of the submandibular triangle?
the inferior border of the mandible
What are the sides of the submandibular triangle?
the anterior and posterior bellies of the digastric muscle
What nerve innervates all the intrinsic and all the extrinsic muscles of the tongue (except for palatoglossus)?
CN XII
What nerve innervates palatoglossus?
CN X
What are some of the roles of the mylohyoid muscles?
supporting the floor of the mouth, enabling the tongue to press against the palate in swallowing, and also raising the hyoid
What are some of the roles of the geniohyoid muscles?
supporting the hyoid bone, pulling it anteriorly and a bit upward
What is the origin of the geniohyoid?
inferior mental spine of the mandible (inserts at the hyoid bone)
What is the origin of the mylohyoids?
the mylohyoid line of the mandible (inserts of the hyoid bone)
What muscles lie on the superficial surface of the mylohyoids?
the anterior digastric m.
What is the mylohyoid innervated by?
nerve to mylohyoid, a branch of the mandibular division of CN V (V3)
What does the nerve to mylohyoid branch from?
the inferior alveolar n. as that nerve enters the mandibular foramen
Where does the n. to mylohyoid run? Along with?
in the mylohyoid groove along with the mylohyoid branch of the inferior alveolar artery
What other muscle does the n. to mylohyoid innervate?
the anterior digastric belly
What is the posterior digastric belly innervated by?
facial nerve
Why do the anterior and posterior digastric bellies have different innervation?
because they are derived from different pharyngeal arches, I and II
What muscle attached to the superior mental spines of the mandible?
genioglossus
What muscle attached to the inferior mental spines of the mandible?
geniohyoid
What muscle inserts at the digastric fossa?
the anterior digastric
What are the possible actions of contraction of the geniohyoid?
the geniohyoid muscles can either pull the hyoid anteriorly and slightly superiorly, but if the hyoid bone is fixed in place by contraction of the infra hyoid muscles, contraction can help to depress the mandible
What is the innervation of geniohyoid?
C1 from the cervical plexus (that runs partially with the hypoglossal nerve)
What nn. run with the hypoglossal nerve during their course?
the nerve to geniohyoid, nerve to thyrohyoid, and superior root of the nasa cervicalis. The branch of C1 to the geniohyoid extends with the hypoglossal the furthest
What are the extrinsic muscles of the tongue?
genioglossus, hyoglossus, styloglossus, and the palatoglossus
What are the insertion points of the genioglossus?
primarily in the lateral aspect of the intrinsic tongue muscles but some fibers insert on the hyoid bone