Cranial Nerves X, XI, and XII

Question 1

Describe the path of the special visceral efferent fibers of the Vagus Nerve (CNX)

Answer 1

From medulla oblongata; leaves cranial cavity through the jugular foramen.

Nucleus ambiguus

• Innervates
  
  • pharyngeal muscles (pharyngeal plexus w/ CNIX)
  • muscles of soft palate
  • laryngeal muscles

Question 2

Describe the path of the visceral efferent fibers of the Vagus Nerve (CNX)

Answer 2

From medulla oblongata; leaves cranial cavity through the jugular foramen.

Dorsal vagal nucleus

• Synapse in prevetebral or intramural ganglio; innervate smooth muscle and glands of
  
  • thooracic viscera
  • abdominal viscera

Question 3

Describe the path of somatic afferent fibers of the Vagus Nerve (CNX)

Answer 3

From medulla oblongata; leaves cranial cavity through the jugular foramen.

Spinal nucleus of trigeminal nerve

• Superior (jugular) ganglion receives peripheral fibes from
  
  • dura in posterior cranial fossa
  • skin of ear, external auditory canal

Question 4

Describe the path of special visceral afferent fibers from the Vagus Nerve (CNX)

Answer 4

From medulla oblongata; leaves cranial cavity through the jugular foramen.

Nucleus of solitary tract (superior part)

• Inferior nodose ganglion receives peripheral processes from
  
  • taste buds on the epiglottis and root of the tongue

Question 5

Describe the path of visceral afferent fibers from the vagus nerve (CNX)

Answer 5

From medulla oblongata; leaves cranial cavity through the jugular foramen.

Nucleus of solitary tract (inferior part)

• Inferior ganglion receives peripheral processes from
  
  • mucosa of lower pharyx at its esophageal junction
  • laryngeal mucosa above (superior layrngeal) and below (inferior laryngeal) the vocal fold
  • pressur ereceptors in the aortic arch
  • chemoreceptors in the para-aortic body
  • thoracic and abdominal viscera

Question 6

What nerve is important to help identiy cranial nerve IX and X?

Answer 6

Accessory CNXI

come up foramen magnum and out the jugular foramen

Question 7

Identify the branches of the Vagus nerve

Answer 7

Question 8

How can you distinguish glossopharyngeal from vagus coming out of the jugular foramen?

Answer 8

Glossopharyngeal is more anterior than vagus

Question 9

What palate muscle derives somatic motor innervation from the vagus nerve?

Answer 9

palatoglossus muscle

Question 10

Identify the various innervations of tongue for taste and sensation

Answer 10

Question 11

Identify the various innervation patterns of the auricle

Answer 11

Question 12

Draw these relationships

Question 13

Where are the 6 common lesion sites on the Vagus Nerve (CNX)?

Answer 13

1. Brainstem
2. Skull base (jugular foramen)
3. Carotid (surgery)
4. Thyroid system (surgery)
5. Aorta
6. Bronciole

Question 14

The following symptoms indicated a problem with which cranial nerve?

Low/soft voice

Aspirate fluids/food & difficulty swallowing

Asymmetrical elevation of soft palate

Answer 14

Vagus Nerve (CNX)

Question 15

Describe the route of the Accessory Nerve (CNXI)

Answer 15

From spinal roots C1-C5, up through magnum foramen

out the skull through Jugular Foramen, crosses posteriorly to the occipital artery adn the innervates the stenocleidomatoid adn the trapezius

Question 16

Which nerve functionality are you assessing when asking your patients to rotate their neck and shrug your shoulders

Question 17

Which nerve passes deep to the occipital condyles?

Answer 17

They hypoglossal nerve in the hypoglossal canal

Question 18

Describe the course of the Hypoglossal nerve

Answer 18

Comes out of the hypoglossal posterior and medial to the other cranial nerves in that area. It then moves lateally to wrap aroun the external carotid below the occipital . It goes between the mylohyoid and hyoglossal muscles to eneter the oral cavity to innervate intrinsic and extrinsic muscles of the tongue

Question 19

What nerve innervate they thyrohyoid?

Answer 19

C1, through catching a ride with the Hypoglossal nerve

Question 20

What nerve are you testing when you ask a patient to stick out their tongue, looking for asymmetry?

Answer 20

Hypoglossal nerve (CNXII)

Question 21

Cranial nerve testing?

1. CN I
2. CN II
3. CN III, IV, VI
4. CN III
5. CN V

Answer 21

• CN I : smells, pleasant
• CN II : visual acuity, fields
• CN III, IV, VI : H-test (movement of the eye)
• CN III : pupilary reflex/ accommodate (lens adjustment)
• CN V : face sensation, clinch teeth & open against resistance
• CN VII : muscles facial expresison
• CN VIII : balance, Rinne/Weber
• CN IX : Gag reflex, Aahh – sym
• CN X : swallow, hoarseness
• CN XI : head movement, shrugs
• CN XII : tongue out