TUT Structure and function of the brainstem

Question 1

Edinger-Westphal nucleus (Oculomotor N. III)

Function?

Answer 1

Control of pupillary constriction and lens accommodation

Question 2

Vestibulocochlear nucleus (N. VIII) Function?

Answer 2

Balance and hearing. Involved in the initiation of postural reflexes through the vestibulospinal tracts.

Question 3

Patients with Parkinsonism can develop ________ tract dysfunction.

Answer 3

Patients with Parkinsonism can develop vestibulospinal tract dysfunction.

Due to last confidence in maintaining balance due to vestibulocochleal system disturbance

Question 4

Function of trigeminal nuclei?

Answer 4

Mesencephalic: Mouth proprioception

Motor: Muscle of mastication

Pontine/chief sensory Discrimination touch of face

Spinal: Pain and temp from face, back of tongue, pharnx, larynx and ear

Question 5

Which 2 motor CN nuclei do not lie medially?

Answer 5

Facial

Ambiguus

Question 6

Function of nucleus ambiguus?

Answer 6

Motor to pharynx and larynx via CN IX and X

Question 7

Which CN are around at the salivatory nuclei for PS stimualtion?

Answer 7

CN VII: Lacrimal and nasal glands

CN VII: Salivary glands

CN IX: Salivary glands

Question 8

What info is relayed from solitary nucleus in the following nerves:
CN VII, IX, X?
IX?
X?

Answer 8

CN VII, IX, X: Special visceral afferent i.e. TASTE
IX: General visceral afferent for carotid baroreceptors
X: General visceral afferent to pharynx/larynx/lungs/gut

Question 9

Function of the dorsal motor nucleus of the vagus?

Answer 9

Function:

1. secreto- motor to lungs and gut
2. control of heart rate

Question 10

Face representation in ______ motor areas

Answer 10

cingular motor area

Question 11

Difference in facial expression in UMN and LMN lesion?

Answer 11

LMN: Lesions final common output to forehead and lower face. Leading to complete paralysis of one side of face. Cannot wrinkle forehead.

UMN: Forehead has bilateral control therefore one-sided weakness only seen at lower face

Question 12

Name the non-cranial nerve nuclei at the midbrain and functions?

Answer 12

Medial geniculate: Relay auditory stimuli to cerebral cortex

Red nucleus:Motor co-ordination (part of extra pyramidal system)

Substantia nigra:
Motor co-ordination (part of extra pyramidal system)

Superior colliculus: Co-ordinates eye movements in response to visual and other stimuli

Inferior colliculus: Co-ordinates heads and trunk in response to auditory stimuli

Reticular formation (RetF): Consciousness & cortical arousal

Question 13

Name the non-cranial nerve nuclei at the pons and their functions?

Answer 13

Pontine nuclei: Link between cerebral cortex and cerebellum

Reticular formation (RetF): Consciousness & cortical arousal

Question 14

Name the non-cranial nerve nuclei at the medulla and their functions?

Answer 14

Olive: Auditory control (superior olive) and movement control (inf olive)

Vital centres: Regulate HR, RR, vasodilation

Non-vital centres: Co-ordinate swallowing, vomitting, cough, sneezing, hiccupping

Reticular formation (RetF): Consciousness & cortical arousal

Question 15

Name midbrain nuclei (non-CN)?

Answer 15

Medial geniculate:

Red nucleus:

Substantia nigra:

Superior colliculus:

Inferior colliculus:

Reticular formation (RetF):

Question 16

What features are found at the anterior and posterior lower midbrain cross section?

Answer 16

Anterior: Cerebral peduncle
Posterior: Colliculi

Question 17

What features are found at the anterior and posterior pons cross section?

Answer 17

Anterior: Anterior bulging
Posterior: 
4th Ventricle
Abducens nucleus in midline
Cerebellar peduncles laterally

Question 18

What features are found at the anterior and posterior upper medulla cross section?

Answer 18

Anterior: olives and pyramid
Posterior: 
4th ventricule
Hypoglossal nucleus
Dorsal vagal nucleus

Question 19

Function of MLF?

Answer 19

Medial longitudinal fascicular
Contralateral motor supply
To co-ordinate eye/neck movement
Medial position in BS and SC

Question 20

4 medial brainstem tracts/nuclei

Answer 20

Medial lemniscus (X) 
Motor tracts- somatic (X) 
MLF (X)
\+
Motor nuclei

Question 21

4 side brainstem tracts/nuclei

Answer 21

Spino-cerebellar (I) 
Spino-thalamic (X) 
Sympathetic (I)
\+
Somatic sensory nuclei

Question 22

Midbrain arterial supple

Answer 22

Midbrain:  
PCA 
SCA
Basilar 
Post communicating

Question 23

Pons arterial supple

Answer 23

Pons:
Basilar
AICA

Question 24

Medulla arterial supply

Answer 24

Medulla:
AICA + PICA
Vertebral
Anterior + posterior spinal