Brainstem and cranial nerves

Question 1

LO 11 Describe the arrangement of cranial nerve nuclei.

Answer 1

• afferent nuclei: lateral and sensory
• efferent nuclei: medial and motor
• General Somatic Efferent: occulomotor, trochlear, abducens and hypoglossal
• Special Visceral Efferent: trigeminal, facial, ambiguus, accessory
• General Visceral Efferent: Edinger Westphal, Salivatory, Vagus

Question 2

LO11 Explain the origins of the cranial nerves and explain how this relates to the development of the brainstem

Which is the only one cranial nerve that emerges from the lateral part of the pons?

Answer 2

Trigeminal

Question 3

LO11 Explain the origins of the cranial nerves and explain how this relates to the development of the brainstem

Which is the only cranial nerve that emerges from the back of the brain?

Answer 3

Trochlear

Question 4

Name and describe the four functional subtypes of the cranial nerves. (Functional classification 1)

Answer 4

1. General somatic afferent (GSA): sensation from the skin and mucous membranes
2. General visceral afferent (GVA): sensation from the GI tract, heart, vessels and lungs
3. General somatic efferent (GSE): muscle for eye and tongue movements
4. General visceral efferent (GVE): pre-ganglionic parasympathetic

Question 5

Describe Functional Classification 2 of cranial nerves.

Answer 5

1. Special somatic afferent: vision, hearing and equilibrium
2. Special visceral afferent: smell and taste
3. Special visceral efferent: muscles involved in chewing, facial expression, swallowing, vocal sounds and turning head

Question 6

LO12 Identify the three structures in the brainstem and recall their functions

Answer 6

It divides into: medulla oblongata, pons and midbrain

Question 7

Posterior view of brainstem. Label the diagram

Answer 7

Spe

Question 8

Anteriori view of brainstem. Label the diagram

Answer 8

Question 9

Describe the development of the brainstem

Answer 9

In embryonic spinal cord:

• information goes into the spinal cord via the dorsal root and leaves the spinal cord via the ventral root
• This is different to the embryonic brainstem

In embryonic rhombencephalon:

• In the brainstem the alar plate opens up and you have a ventricle here. - afferent nuclei: lateral and sensory - efferent nuclei: medial and motor

Question 10

Distinguish between the internal structure of the brainstem

Answer 10

Question 11

What is lateral medullary syndrome?

Give its symptoms.

Answer 11

Thrombosis of vertebral artery or PICA (posterior inferior cerebellar artery).

Results in:

• vertigo
• ipsilateral cerebral ataxia
• ipsilateral loss of pain/ thermal sense
• horner’s syndrome (loss of sympathetic innervation to the head and neck)
• hoarseness, difficulty in swallowing
• contralateral loss of pain/ thermal sense