Cranial Nerves

Question 1

How is the cerebellum connected to the brainstem?

Answer 1

By three cerebellar peduncles (white fibre tracts)

Question 2

What Nuclei does the brainstem contain?

Answer 2

Of 9 out of 12 cranial nerves.

III - XII except XI ( accessory nerve which has its nuclei in spinal cord)

Question 3

What are the three internal structures of the brainstem? ( horizontal cross section )

Answer 3

( In a horizontal crossection)

Tectum at the posterior end (just behind ventricular system)
Tegmentum near middle
Base at anterior end

Question 4

What structures can we see on the anterior aspect of the brainstem? 6

Answer 4

Optic chiasm, Pituitary stalk, Mammillary body, Cerebral peduncle, Pyramidal decussation, medullary pyramids

Question 5

What structures can we see on the posterior aspect of the brainstem? 5

Answer 5

Pineal glad, Superior colliculus, Inferior colliculus, Trochlear nerve, Dorsal columns

Question 6

What tracts are in the cerebral peduncles?

Answer 6

Descending tracts - corticospinal and corticobulbar

Question 7

What level to cranial nerves V, VI, VII, VIII emerge at?

• Nerve IV emerges from midbrain

Answer 7

At Pons - where the middle cerebellar pedeuncle is

Question 8

Why is the upper open medulla named as such?

Answer 8

The 4th ventricle doesn’t have a ‘roof’ and the cerebellum sits posterior to it.

Question 9

Which cranial nerves emerge from the medulla?

Answer 9

Cranial Nerves IX, X, XII

Question 10

At which area does the 4th ventricle become the central canal?

Answer 10

Closed Lower medulla

Question 11

What structures can you seen in the cross section of the lower medulla?

Answer 11

Central Canal
Dorsal columns
Decussation

Question 12

Which vessels supply the anterior part of the CNS blood supply? e.g. cerebral hemisphere

Answer 12

Internal carotid system mostly supply cerebral hemisphere

Question 13

Which vessels supply the posterior part of the CNS blood supply? e.g. brainstem

Answer 13

Vertebrobasilar system mostly supplies brainstem

Question 14

How can Cranial nerves be grouped as the following?:
GSA
GSE
GVA
GVE

Answer 14

GSA - Fibres from sensation skin muscles joints of head and check

GSE - Fibres innervate skeletal muscles

GVA - Sensation from viscera of head neck thoroax and abdomen

GVE - Fibres from preganglionic preganglionic parasympathetic neurons to cranial, thoracic and abdominal viscera

Question 15

Which fibres deal with sense of hearing and balance in brainstem?

Answer 15

SSA - Special somatic afferent

Question 16

Which fibres carry taste sensation?

Answer 16

SVA - special visceral afferent

Question 17

Which fibres innervate skeletal muscles of jaw, face, larynx and pharynx?

Answer 17

SVE - special visceral efferent

Question 18

Which nerves do not emerge from the brainstem?

Answer 18

Nerves I and II

Optic and olfactory nerves