Muscles & Innervations

Question 1

What are the suprahyoid muscles responsible for?

Answer 1

Hyolaryngeal excursion = elevating the hyoid and moving it anteriorly to protect the airways as epiglottis closes.

Question 2

What is the purpose of the palatal muscles?

Answer 2

Velopharyngeal seal

Question 3

What is the only palatal muscle innervated by the Trigeminal nerve (V)?

Answer 3

Tensor veli Palatini

Question 4

What is the tongue important for swallowing? (3)

Answer 4

1) Formation and manipulation of bolus.
2)
3) Oral transit.

Question 5

Which cranial nerve inner area the tongue?

Answer 5

Hypoglossal nerve (XII)

Question 6

Which cranial nerves innervate hyoid elevation (hyolaryngeal excursion)?

Answer 6

1) Trigeminal (V)
2) Facial (VII)
3) Hypoglossal (XII)

Question 7

How is the face divided in terms of facial nerve innervation (upper vs. lower, bilateral vs. unilateral)?

Answer 7

Upper face receives BILATERAL (ipsilateral & contralateral) from UMN tracts.

Lower face receives only CONTRALATERAL (unilateral) innervation —> results in atrophy of muscles of mastication on the AFFECTED side with resulting decreased strength of bite.

Question 8

List the cranial nerves involved in epiglottic deflection (3)

Answer 8

V - Trigeminal
VII - Facial
XII - Hypoglossal

Question 9

List the cranial nerves involved in the opening of the UES (4)

Answer 9

V - Trigeminal
VII - Facial
X - Vagus
XII - Hypoglossal

Question 10

With respect to swallowing, why is sensory ability important? (3)

Answer 10

1) Sense of bolus for swallow initiation
2) Proprioception
3) Sense residue

Question 11

What nerves and muscles are used in the oral preparation phase (in order of activation)? (7)

Answer 11

1) Obicularis oris (CN VII) - lip opening and closing, lip seal.
2) Buccinator (CN VII) - keeps bolus within dental vault, prevents pocketing of residue in cheeks.
3) Tongue sensation (taste & touch, CN V, VII, IX) - determines taste, size, texture, and location of bolus.
4) Tongue muscles for altering shape and tone of tongue during oral preparation to move the bolus (CN XII)
5) Palatoglossus (tongue muscle) for glossopalatal seal (CN X) - prevents premature posterior spillage into pharynx.
6) Muscles of mastication (CN V) - facilitates chewing, breaks down boils and mixes with saliva.
7) Salivation (CN VII, IX) - lubricates bolus