Submandibular Triangle

Question 1

What is the base of the submandibular triangle?

Answer 1

the inferior border of the mandible

Question 2

What are the sides of the submandibular triangle?

Answer 2

the anterior and posterior bellies of the digastric muscle

Question 3

What nerve innervates all the intrinsic and all the extrinsic muscles of the tongue (except for palatoglossus)?

Answer 3

CN XII

Question 4

What nerve innervates palatoglossus?

Answer 4

CN X

Question 5

What are some of the roles of the mylohyoid muscles?

Answer 5

supporting the floor of the mouth, enabling the tongue to press against the palate in swallowing, and also raising the hyoid

Question 6

What are some of the roles of the geniohyoid muscles?

Answer 6

supporting the hyoid bone, pulling it anteriorly and a bit upward

Question 7

What is the origin of the geniohyoid?

Answer 7

inferior mental spine of the mandible (inserts at the hyoid bone)

Question 8

What is the origin of the mylohyoids?

Answer 8

the mylohyoid line of the mandible (inserts of the hyoid bone)

Question 9

What muscles lie on the superficial surface of the mylohyoids?

Answer 9

the anterior digastric m.

Question 10

What is the mylohyoid innervated by?

Answer 10

nerve to mylohyoid, a branch of the mandibular division of CN V (V3)

Question 11

What does the nerve to mylohyoid branch from?

Answer 11

the inferior alveolar n. as that nerve enters the mandibular foramen

Question 12

Where does the n. to mylohyoid run? Along with?

Answer 12

in the mylohyoid groove along with the mylohyoid branch of the inferior alveolar artery

Question 13

What other muscle does the n. to mylohyoid innervate?

Answer 13

the anterior digastric belly

Question 14

What is the posterior digastric belly innervated by?

Answer 14

facial nerve

Question 15

Why do the anterior and posterior digastric bellies have different innervation?

Answer 15

because they are derived from different pharyngeal arches, I and II

Question 16

What muscle attached to the superior mental spines of the mandible?

Answer 16

genioglossus

Question 17

What muscle attached to the inferior mental spines of the mandible?

Answer 17

geniohyoid

Question 18

What muscle inserts at the digastric fossa?

Answer 18

the anterior digastric

Question 19

What are the possible actions of contraction of the geniohyoid?

Answer 19

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

Question 20

What is the innervation of geniohyoid?

Answer 20

C1 from the cervical plexus (that runs partially with the hypoglossal nerve)

Question 21

What nn. run with the hypoglossal nerve during their course?

Answer 21

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

Question 22

What are the extrinsic muscles of the tongue?

Answer 22

genioglossus, hyoglossus, styloglossus, and the palatoglossus

Question 23

What are the insertion points of the genioglossus?

Answer 23

primarily in the lateral aspect of the intrinsic tongue muscles but some fibers insert on the hyoid bone

Question 24

Contraction of different groups of genioglossus fibers have different effects on the tongue. What does contraction of its inferior fibers cause?

Answer 24

projection of the tongue out of the mouth, called protraction of the tongue

Question 25

What does contraction of the superior fibers of the genioglossus cause?

Answer 25

pulls the tip of the tongue back inside the mouth and downward, called retraction of the tongue

Question 26

What does contraction of all of the fibers of the genioglossus, contraction of the intrinsic fibers, and other supporting muscles, such as the mylohyoids cause?

Answer 26

causes the tongue to protrude superiorly, pushing against the palate, an action important for propelling a bolus of food posteriorly toward the pharynx

Question 27

What does contraction of the hyoglossus cause? Where does it span

Answer 27

the hyoglossus spans between the greater horn of the hyoid bone and runs anteriorly and superiorly to blend in with the tongue. Contraction pulls down on the sides of the tongue and a retractor of the tongue, often flattening the tongue

Question 28

What muscle blends into the side of the tongue close to the hyoglossus?

Answer 28

the styloglossus

Question 29

What does contraction of the styloglossus cause?

Answer 29

it pulls the tongue posteriorly

Question 30

What is the anterior tonsillar pillar?

Answer 30

the boundary between the oral cavity and the oropharynx

Question 31

What muscle forms the anterior tonsillar pillar?

Answer 31

palatoglossus (only tongue muscle innervated by CN X)

Question 32

If a person had a lesion of the left hypoglossal nerve, which side would the tongue protrude to if you stuck it out?

Answer 32

the left

Question 33

The deep part of the submandibular gland wraps around which muscle?

Answer 33

the posterior free margin of the mylohyoid

Question 34

Which part of the submandibular gland does the duct originate from?

Answer 34

the deep part

Question 35

Where does the submandibular duct end?

Answer 35

at the sublingual caruncle in the floor of the oral cavity under the tongue. This is where the submandibular gland saliva is secreted. A sublingual caruncle lies on either side of the frenulum

Question 36

Where does the lingual nerve (branch of V3) originate?

Answer 36

the infratemporal fossa

Question 37

Which gland most commonly develops stones?

Answer 37

the submandibular gland

Question 38

What muscle does the lingual nerve descend down at the level of the tongue?

Answer 38

the styloglossus (and slightly on the very superior, lateral aspect of the hyoglossus)

Question 39

The submandibular ganglion is located where?

Answer 39

directly inferior to the lingual nerve, sandwiched in between that and the deep part of the submandibular gland

Question 40

Does the lingual artery course superficial or deep to the hyoglossus?

Answer 40

deep to it

Question 41

What is the function of the lingual nerve?

Answer 41

GSA innervation to the anterior 2/3 of the tongue (to circumvallate papillae) and GSA to the floor of the mouth and lingual gingiva of the mandible

Question 42

Where are the cell bodies of the lingual nerve fibers?

Answer 42

in the semilunar ganglion located in the middle cranial fossa

Question 43

Note on the distribution of the lingual artery and veins in relation to the hyoglossus

Answer 43

the artery is completely deep to the hyoglossus while lingual veins exist on both the superficial and deep surfaces of the hyoglossus. Veins drain to the IJV

Question 44

What provides SA innervation to the taste of the anterior 2/3rd of the tongue and GVE parasympathetic to the submandibular and sublingual glands?

Answer 44

CN VII

Question 45

Where are the cell bodies of the lingual nerve?

Answer 45

in the trigeminal ganglion (aka semilunar, aka Gasser's). This a sensory ganglion

Question 46

What provides GSA innervation to the posterior 1/3 of the tongue?

Answer 46

via CN IX

Question 47

Where do the sensory ganglia of CN IX and X lie?

Answer 47

within or just below the jugular foramen (superior is within, inferior is just below)

Question 48

What branch of CN VII carrier SA taste fibers from the anterior 2/3 of the tongue?

Answer 48

the chorda tympani branch remember that GSA to the anterior 2/3rd is from the lingual nerve

Question 49

Where are the cell bodies of SA fibers of the tongue found?

Answer 49

within the geniculate ganglion, the peripheral ganglion of the 7th nerve

Question 50

SA and GSA for the posterior 1/3 of the tongue is from what nerve?

Answer 50

CN IX

Question 51

What does the chorda tympani branch of CN VII do?

Answer 51

SA taste fibers to the anterior 2/3 of the tongue and preganglionic parasympathetic fibers from one of the motor nuclei of VII in the brain to the submandibular ganglion. Postganglionic fibers then run from the submandibular ganglion to the submandibular and sublingual lands to provide GVE parasympathetics

Question 52

What nerve does the chorda tympani run with?

Answer 52

the lingual nerve, having joined it in the infra temporal fossa

Question 53

Which is deep to the superficial submandibular gland, the facial artery or facial vein?

Answer 53

the facial artery

Question 54

What foramen does the chorda tympani branch of the facial n. come through?

Answer 54

the stylomastoid foramen

Question 55

Where does the chorda tympani nerve run before joining with the lingual n.?

Answer 55

the infratemporal fossa

Question 56

Describe the course of the chorda tympani n.?

Answer 56

It comes off the brain, through the IAM, through the facial canal in the temporal bone and has its sensory ganglion in the geniculate ganglion. It then goes through SMF into the infra temporal fossa and then meets up with the lingual n. to go the anterior 2/3 of the tongue

Question 57

The lingual n. is a branch of?

Answer 57

V3

Question 58

What is achalasia?

Answer 58

failure of the lower esophageal sphincter to respond to the swallowing reflex