Cranial nerves

Question 1

CNVII facial nerve and CNIX Glossopharyngeal are responsible for the special sense taste on the tongue. Which is responsible for the anterior 2/3 and which is responsible for the posterior 1/3?

Answer 1

CNVII facial nerve is responsible for the anterior 2/3 and

CNIX Glossopharyngeal is responsible for the posterior 1/3

Question 2

There are 3 cranial nerves involved in the special sense taste. Taste is sensed by the tongue, pharynx and the epiglottis (which covers the larynx [voice box] while eating). Which cranial nerve does what?

Answer 2

CNVII facial nerve: Taste anterior 2/3

CNIX Glossopharyngeal: Taste posterior 1/3 (further twds throat) and some pharynx

CNX Vegas: Taste in epiglottis (covering larynx)

Question 3

There are 3 cranial nerves involved in motor eye movement. Which are these? What are the other functions of CNIII?

Answer 3

CNIII Oculomotor: Also parasympathetic reflex: Pupillary sphincter (pupil contraction) and ciliary muscles (lens)

CNIV Trochlea
CNVI Abducens

Question 4

CNV Trigeminal nerve is named for it’s 3 branches of somatosensation. What are these?

It also transmits somatosensation for another area within one of the 3 (the same as a special sense area for CNVII) and motor information for 1 process. State these .

Answer 4

CNV Trigeminal somatosensation for:

Face
Top of head
Meninges: (think migraines: A pain in the meninges).

CNV Trigeminal: Somatosensation for anterior 2/3 tongue (think CNVII special sensory area)

CNV Trigeminal: Motor for mastication

Question 5

Somatosensation and motor for the face as a whole are controlled by which 2 cranial nerves?

Answer 5

CNVII Facial nerve is responsible for motor output for the face.

CNV Trigeminal nerve is responsible for somatosensation for the face.

Question 6

CNVII Facial nerve is responsible for 4 processes. What are they?

Answer 6

1. Motor: Facial expressions
2. Somatosensation for the ear
3. Parasympathetic activation of the lachrymal (tear) and salivary (parotid) glands
4. Special sense: Taste in the anterior 2/3 tongue

Question 7

CNVIII vestibulocochlear nerve is responsible for 2 special sense processes of the inner ear. What are they?

Answer 7

1. Equilibrium (from the vestibule of the inner ear)

2. Audition from the cochlear (of the inner ear)

Question 8

CNX Vagus is called ‘the wonderer’. Why is this?

Answer 8

The vagus nerve wanders all over the body, innervating viscera, the heart, oesophagus and lungs.

Question 9

4 cranial nerves are involved in the parasympathetic response. Which nerves are they and what do they do?

Answer 9

CNIII Oculomotor causes ciliary constriction and pupillary dilation

CNVII Facial nerve causes salivation (parotid gland) and lachrymal gland activation (crying)

CNIX Glossopharyngeal causes activation of the parotid (salivary) glands

CNX Vagus nerve innervates various viscera (pancreas, stomach, small intestine), heart, oesophagus and lungs