Cranial Nerves

Question 1

List the cranial nerves

Answer 1

1. Olfactory
2. Optic
3. Oculomotor nerve
4. Trochlear nerve
5. Trigeminal nerve
6. Abducen nerve
7. Facial nerve
8. Vestibulocochlear nerve
9. Glossopharyngeal nerve
10. Vagus nerve
11. Accesory nerve
12. Hypoglossal nerve

Question 2

How do you test optic nerve?

Answer 2

1. Visual acuity
2. Pupillary response
3. Visual fields
4. Visual inattention
5. Accomodation
6. Fundoscopy

Question 3

What muscles does occulomotor nerve control?

Answer 3

• Superior, medial and inferior rectus
• Inferior oblique and levator palpebrae muscles
• Parasympathetic innervation of contrictor pupillae (pupil size) and ciliary muscle (accomodation)

Question 4

What does the trochlear nerve innervation?

Answer 4

1. Superior oblique muscle

Question 5

What does the abducens nerve innervate?

Answer 5

Lateral rectus muscle

Question 6

What does the trigeminal nerve supply?

Answer 6

Sensation to face

Motor function to muscles of mastication

Question 7

What does facial nerve innervate?

Answer 7

• Muscles of facial expression
• Anterior 2/3rd of tongue for taste
• Secretomotor to submandibular and sublingual glands

Question 8

What does the glossopharngeal nerve innervation?

Answer 8

• Sensation from pharynx and tonsils
• Sensation and taste from posterior 1/3 of tongue
• Innervates stylopharngeus muscles

Question 9

What does vagus nerve innervate?

Answer 9

Sensation and innervat4es paletine, pharyngeal and laryngeal muscles

Question 10

What does accessory nerve innervate?

Answer 10

Upper trapezius and sternocleidomastoid muscles

Question 11

What does hypoglossal nerve innervate?

Answer 11

Muscles of the tongue

Question 12

What eye muscles do the following innervate:

• occulomottor (III)
• trochlear (IV)
• abducens (VI)

Answer 12

• Occulomotor
  
  • Superior, medial and inferior rectus
  • Inferior oblique
  • Levator palpebrae
• Trochlear
  
  • Superior oblique
• Abducens
  
  • Lateral rectus

Question 13

What is the difference between UMN and LMN facial nerve palsy?

Answer 13

UMN spares upper face, affects mid and lower contralateral side

LMN is complete hemiplagia of ispilateral side

Question 14

What are the different kinds of visual field defects?

Answer 14

• Bitemproal hmianopia
  
  • Loss of temporal visual field in both eyes
  • Usually due to optic chiasm compression (pituitary adenoma etc)
• Homonymous field defects
  
  • Affects same side of visual field in each eye
  • Usually due to stroke or tumour
• Monocular vision loss
  
  • Due to optic nerve pathology, loss of vision in that eye