The brainstem

Question 1

The mamillary bodies are part of which system?

Answer 1

Limbic system

Question 2

What causes the bulge in the floor of the 4th ventricle?

Answer 2

CN VII wrapping around the nucleus of CN VI

Question 3

What are the 2 main arteries that supply the brain + brainstem?

Answer 3

Internal carotid arteries + Vertebral arteries

Question 4

CN’s III + IV can be compressed by an aneurysm in which 2 arteries?

Answer 4

Superior cerebellar artery + Posterior cerebral artery

Question 5

Which 2 arteries supply the midbrain?

Answer 5

Superior cerebellar artery
Posterior cerebral artery

Question 6

Which artery supplies the pons?

Answer 6

Basilar artery w/ pontine branches

Question 7

Which 3 arteries supply the medulla?

Answer 7

Anterior spinal artery
Vertebral arteries
Posterior inferior cerebellar artery (PICA)

Question 8

Starting from medial to lateral, what is the arrangement of the 3 layers of nuclei in the brainstem?

Answer 8

Somatic motor
Visceral motor & visceral sensory
Somatic sensory

Question 9

What is meant by branchial motor fibres?

Answer 9

Skeletal muscle derived from pharyngeal arches

Question 10

What are the 4 somatic motor nuclei in the brainstem?

Answer 10

CN III - oculomotor nucleus
CN IV - trochlear nucleus
CN VI - abducens nucleus
CN XII - hypoglossal nucleus

Question 11

What is the function of the oculomotor nucleus?

Answer 11

Motor to all eye muscles except lateral rectus and superior oblique

Question 12

What is the function of the trochlear nucleus?

Answer 12

Motor to superior oblique muscle of the eye

Question 13

What is the function of the abducens nucleus?

Answer 13

Motor to lateral rectus of the eye

Question 14

What is the function of the hypoglossal nucleus?

Answer 14

Motor to the tongue

Question 15

What are the 4 somatic sensory nuclei in the brainstem?

Answer 15

CN V - mesencephalic nucleus
CN V - principal nucleus
CN V - spinal nucleus
CN VIII - vestibulocochlear nucleus

Question 16

What is the function of the mesencephalic nucleus?

Answer 16

Proprioception

Question 17

What is the function of the principal nucleus?

Answer 17

Light touch

Question 18

What is the function of the spinal nucleus?

Answer 18

Pain & temperature

Question 19

Which 3 CN’s hitchhike on the spinal nucleus of CN V?

Answer 19

VII
IX
X

Question 20

What are the 4 parasympathetic nuclei in the brainstem?

Answer 20

CN III - Edinger-Westphal nucleus
CN VII - superior salivatory nucleus
CN IX - inferior salivatory nucleus
CN X - dorsal vagal nucleus

Question 21

What is the function of the Edinger-Westphal nucleus?

Answer 21

Pupillary light reflex

Question 22

What is the function of the superior salivatory nucleus?

Answer 22

Parasympathetics to lacrimal glands + all salivary glands (except parotid)

Question 23

What is the function of the inferior salivatory nucleus?

Answer 23

Parasympathetics to parotid gland

Question 24

What are the 3 branchial motor nuclei in the brainstem?

Answer 24

CN V - trigeminal nucleus
CN VII - facial nucleus
CN IX, X, XI - nucleus ambiguus

Question 25

What is the function of the trigeminal nucleus?

Answer 25

Branchial motor to muscles of mastication

Question 26

What is the function of the facial nucleus?

Answer 26

Branchial motor to muscles of facial expression

Question 27

What is the function of the nucleus ambiguus?

Answer 27

Branchial motor to pharynx, larynx, soft palate

Question 28

What is the function of the dorsal vagal nucleus?

Answer 28

Autonomic control to body - heart, Gi tract, lungs

Question 29

Which 4 structures would be knocked out with a block in the PICA?

Answer 29

Sensory nucleus (CN V) Sympathetic nerves Spinocerebellar tract Spinothalamic tract

Question 30

Which 4 structures would be knocked out with a block in the anterior spinal artery?

Answer 30

Motor nuclei Medial longitudinal fasciculus Medial lemniscus Motor corticospinal

Question 31

Is bulbar palsy a UMN or LMN lesion?

Answer 31

LMN

Question 32

Is pseudobulbar palsy a UMN or LMN lesion?

Answer 32

UMN

Question 33

Why is there a high likelihood that a pseudobulbar palsy will turn into a medical emergency?

Answer 33

Since it is an UMN lesion, spastic paralysis of the pharynx & larynx may develop = airway occlusion

Question 34

Would damage to the Edinger-Westphal nucleus result in ipsilateral or contralateral loss of the pupillary light reflex?

Answer 34

Ipsilateral

Question 35

Would damage to CN IV nucleus result in ipsilateral or contralateral loss of superior oblique function?

Answer 35

Contralateral