Cranial Nerves

Question 1

What is the name of cranial nerve I?

Answer 1

Olfactory

Question 2

What does CN I do?

Answer 2

Sense of smell

Question 3

What is the route of CN I?

Answer 3

Olfactory mucosa

Cribriform plate

Olfactory bulb

Olfactory tract

1.Lateral olfactory stria
Olfactory area of cerebral cortex
2. Medial olfactory stria - carries olfactory nerves to the contralateral olfactory bulb. Crosses the anterior commissure.

Question 4

Which olfactory stria carries olfaction to the cerebral cortex?

Answer 4

Lateral olfactory stria

Question 5

Where do 1st order olfactory neurons synapse with 2nd order neurons?

Answer 5

Olfactory bulb

Question 6

What is the name of the 2nd order cell in the olfactory bulb?

Answer 6

Mitral cell

The olfactory nerve fibres synapse with the mitral cells, forming collections known as synaptic glomeruli

Question 7

How to you test for CN I damage?

Answer 7

Test each nostril separately with a familiar smell

Question 8

When can a loss of smell be due to?

Answer 8

Early signs of Parkinson’s/Alzheimer’s

Viral infection

Anterior cranial fossa #

Cribriform plate #

Question 9

What is the name of CN II?

Answer 9

Optic

Question 10

How does CN II enter the skull?

Answer 10

Optic canal

Question 11

What is the route of CN II?

Answer 11

Retina

Optic nerve

Optic chiasm

Optic tract

Lateral geniculate nucleus of thalamus

Primary visual cortex (occipital lobe)

Question 12

What can cause damage to CN II?

Answer 12

Pituitary adenoma

Pituitary gland is close to the middle cranial fossa

Question 13

What exits the skull via the cribriform plate?

Answer 13

CN I

Question 14

What can cause damage to CN II?

Answer 14

Pituitary adenoma

Pituitary gland is close to the middle cranial fossa

Cavernous sinus compression

Posterior cerebral artery aneurysm

Infection causing thrombosis

Lesion to interpeduncular fossa

Question 15

What travels through the cavernous sinus, and what is near the cavernous sinus?

Answer 15

Through:

Internal carotid artery 
CN III
CN IV
CN Va
CN Vb
CN VI

Near:
Pituitary gland
Sphenoid sinuses

Question 16

Where are the 2 cavernous sinuses?

Answer 16

They sit either side of the sella turcia

Sella turcia contains the PITUITARY GLAND

Question 17

Which muscle opens your eyelid?

Which CN innervates it?

Answer 17

Levator palpebrae

CN III

Question 18

What is the name of CN IV?

Answer 18

Trochlear

Question 19

What is the function of CN IV?

Answer 19

Motor innervation to superior oblique muscle

Question 20

What is the route of CN III?

Answer 20

Oculomotor nucleus (anterior midbrain)

Cavernous sinus

Superior orbital fissure

Question 21

What is the route of CN III?

Answer 21

Oculomotor nucleus (anterior midbrain)

Cavernous sinus

Superior orbital fissure

4/6 extraocular eye muscles

Levator palpebrae superioris (eyelid)

Sphincter pupilae (lens accommodation)

Ciliary eye muscle (constrict pupil)

Question 22

Which artery runs next to CN VI?

Answer 22

Internal carotid artery

Question 23

Which artery runs next to CN III?

Answer 23

Posterior cerebral artery

Question 24

Where is the trigeminal sensory nucleus?

Answer 24

Across the entire brainstem

Question 25

Where is the trigeminal motor nucleus?

Answer 25

Pons

Question 26

Describe the route of CN Va

Answer 26

Trigeminal sensory nucleus

Trigeminal ganglion

Cavernous sinus

Superior orbital fissure

Sensation to upper portion of face

Question 27

Where does CN Va exit the skull?

Answer 27

Superior orbital fissure

Question 28

Where does CN Vb exit the skull?

Answer 28

Foramen rotundum

Question 29

Where does CN Vc exit the skull?

Answer 29

Foramen ovale

Question 30

Describe the route of CN Vb

Answer 30

Trigeminal sensory nucleus

Trigeminal ganglion

Cavernous sinus

Foramen rotundum

Sensation to middle portion of face