Anatomy: Suprahyoid & Infrahyoid Muscles

Question 1

digrastic (posterior belly)

Answer 1

function: elevate hyoid, pull BACK
CN VII (facial)

Question 2

digastric (anterior belly)

Answer 2

function: elevate hyoid, pull FORWARD
CN V (trigeminal)

Question 3

mylohyoid
*what makes this diferent from other suprahyoids?

Answer 3

function: elevate hyoid, pull FORWARD
CN V (trigeminal)
*only unpaired suprahyoid muscle

Question 4

geniohyoid

Answer 4

function: elevate hyoid, pull FORWARD
CN XII (hypoglossal)

Question 5

stylohyoid

Answer 5

function: elevate hyoid, pull BACK
CN VII (facial)

Question 6

thyrohyoid
*what makes this different from the other infrahyoids?

Answer 6

function: draws thyroid & hyoid closer together
CN XII (hypoglossal)
*only infrahyoid that pulls larynx up

Question 7

sternothyroid
*deep to the _________________

Answer 7

function: pulls larynx down
CN XII (hypoglossal)
*sternohyoid

Question 8

sternohyoid
*acts directly on larynx

Answer 8

function: pulls hyoid down
CN XII (hypoglossal)

Question 9

omohyoid (inferior/superior belly)

Answer 9

function: pulls hyoid down
CN XII (hypoglossal)

Question 10

thyroarytenoid
*bulk of ________________________
*antagonist to __________________________

Answer 10

function: increases mass, contracts, relaxes, decreases distance
recurrent layrngeal nerve of CN X (vagus)
*true vocal folds
*cricothyroid

Question 11

lateral cricoarytenoid
*primary ______________ and _________________

Answer 11

function: rocks down and in
recurrent layrngeal nerve of CN X (vagus)
*shortener, adducter

Question 12

cricothyroid (pars oblique/pars recta)
*how is this muscle different from the other intrinsic muscles?
*pars recta is the primary _________________

Answer 12

function
pars oblique - decreases mass, glides thyroid cartilage down
pars recta - rocks thyroid cartilage down, lengthener

superior laryngeal branch CN X (vagus)
*it is the only intrinsic muscle innervated by the (external) superior laryngeal branch of CN X
*lengthener

Question 13

posterior cricoarytenoid
*primary ________________
*antagonist to ________________________

Answer 13

function: rocks out and back
recurrent layrngeal nerve of CN X (vagus)
*abducter
*lateral cricoarytenoid

Question 14

transverse arytenoid
*how is this different from the other intrinsic muscles?
*what would result from hypofunction?

Answer 14

function: draws arytenoid cartilages closer together
recurrent layrngeal nerve of CN X (vagus)
*only unpaired intrinsic muscle
*more medial compression

Question 15

oblique arytenoids
*superficial to ____________________

Answer 15

function: draws tops of arytenoid cartilages closer together
recurrent layrngeal nerve of CN X (vagus)
*transverse arytenoid