Brainstem

Question 1

Cerebral peduncle

Answer 1

cerebrum to spinal cord, pons, CN nuclei

Question 2

Superior cerebellar peduncle (SCP)

Answer 2

cerebellum TO (and from):
anterior spinocerebellar tract
red nucleus
thalamus (VA/VL)

Question 3

Middle cerebellar peduncle (MCP)

Answer 3

FROM pons (cerebral cortex) to cerebellum

cerebral cortex–>pons–MCP–>cerebellum

Question 4

Inferior cerebellar peduncle (ICP)

Answer 4

cerebellumposterior spinocerebellar tract, inferior olive, vestibular nucleus

Question 5

Corticospinal tract

Answer 5

Motor

Decussates at base of medulla

Question 6

Dorsal Column/Medial Lemniscus

Answer 6

• Fine touch, vibration, proprioception

- Decussates mid-medulla

Question 7

Anterolateral System (spinothalamic)

Answer 7

• pain, temp

- Decussates at level of spinal cord

Question 8

Most long tract lesions in brainstem will be ____; most cranial nerve signs will be _____ to lesion

Answer 8

long tract: contralateral

cranial n: ipsilateral

Question 9

Cranial nerves for midbrain, pons, medulla

Answer 9

Midbrain: 3,4

pons: 5,6,7,8
medulla: 9,10,11,12

Question 10

Cranial nerves

Answer 10

CN I – Olfactory
CN II – Optic
CN III – Oculomotor
CN IV – Trochlear
CN V (1,2,3) – Trigeminal
CN VI – Abducens
CN VII – Facial
CN VIII – Vestibulocochlear
CN IX – Glossopharyngeal
CN X – Vagus
CN XI – Accessory
CN XII – Hypoglossal

Question 11

CN nuclei:

midbrain

Answer 11

III
Edinger Westphal Nucleus
IV

Question 12

CN nuclei:

pons

Answer 12

V
Mesencephalic nuc of V
Primary motor nuc of V
Main sensory nuc of V
Spinal nucleus of V (@caudal pons)
VI
VII
VIII (cochlear nucleus and vestibular nucleus at pontomedullary junction)

Question 13

CN nuclei:

medulla

Answer 13

IX (nucleus of solitary tract)
X (nucleus of solitary tract, dorsal motor nucleus of vagus and ventral motor nucleus of vagus aka nucleus ambiguous)
XII (hypoglossal nucleus)
(Spinal nucleus of V is here too)

Question 14

Pupillary light reflex

Answer 14

shining light in one eye will cause pupillary constriction in both eyes
Afferent=II (sensory fibers from retina)
Efferent=III (parasympathetic fibers to ciliary ganglion)

Question 15

MLF

Answer 15

coordinating eye movements with head movements

• MLF
• CN nuclei 3,4,6,8
• Also involves cerebellum, medial vestibulospinal tract (to coordinate neck muscles too)

Question 16

Dorsal motor nuc of X

Answer 16

Preganglionic parasymp vagal neurons to heart and thoracic & abdominal viscera

Question 17

Nucleus Ambiguous

Answer 17

motor vagal neurons to muscles of pharynx, larynx (swallowing, phonation, movement of uvula, gagging)… this nucleus also contains motor fibers to stylopharyngeus muscle which helps in phonation and swallowing (but not gagging)

Question 18

Solitary nucleus

Answer 18

special sensory (taste) from 7, 9, 10

Question 19

Gag reflex

Answer 19

touching the wall of one side of pharynx elicits bilateral gagging response
Afferent=IX (sensory fibers)
Efferent=X (nucleus ambiguous)

Question 20

Jaw Jerk reflex

Answer 20

Downward tapping of jaw causes biilateral contraction of masseter
Afferent = mesencephalic nucleus of V (stretch receptors in masseter)
Efferent = main motor nucleus of V