Caudal Pons

Question 1

Dentate nucleus (deep cerebellar nucleus)

Answer 1

The deep cerebellar nucleus connected to the medial part of the cerebellar hemisphere and the source of most of the remaining fibers in the superior cerebellar peduncle.

For deep cerebellar nuclei, don’t forget: “Fat Guys Eat Donuts.”

Question 2

Globose and Emboliform (deep cerebellar nuclei)

Answer 2

Together = interposed nucleus.

Question 3

Fastigial (deep cerebellar nucleus)

Answer 3

Projects to the (cerebellar) vermis.

Question 4

Superior Cerebellar Peduncle (SCP)

Answer 4

Just forming in the cerebellum. The principal output pathway from the cerebellum.

Question 5

Fourth ventricle

Answer 5

Continuous rostrally with the aqueduct and caudally with the central canal.

Question 6

Vestibular nuclei

Answer 6

Second-order neurons that form vestibulospinal tracts, much of the MLF, and projections to the cerebellum and thalamus. (SSA)

Question 7

Abducens nucleus

Answer 7

Lower motor neurons for the ipsilateral lateral rectus, as well as the interneurons that project through the contralateral MLF to medial rectus motor neurons. (GSE)

Question 8

Internal genu of the facial nerve

Answer 8

Facial nerve fibers—most of them on their way to ipsilateral muscles of facial expression—that hook around the abducens nucleus before leaving the brainstem.

Question 9

Medial longitudinal fasciculus (MLF)

Answer 9

At this levels, fibers from vestibular nuclei and abducens interneurons, active in coordinating eye movements. A lesion here can result in internuclear ophthalmoplegia.

Question 10

Spinal trigeminal tract

Answer 10

Primary afferents from the ipsilateral side of the face, including those conveying information about pain and temperature to caudal parts of the spinal trigeminal nucleus.

Question 11

Spinal trigeminal nucleus

Answer 11

Some primary afferents of the spinal trigeminal tract, particularly those carrying tactile information, end at this relatively rostral level. (GSA)

Question 12

Facial motor nucleus

Answer 12

Lower motor neurons for ipsilateral muscles of facial expression. (SVE)

Question 13

Reticular formation

Answer 13

No description.

Question 14

Raphe nuclei

Answer 14

Widely projecting serotonergic neurons that collectively blanket the CNS. Those in intermediate brainstem levels like this are one source of descending pain-control fibers to the spinal cord, and also project to other brainstem levels and the cerebellum.

Question 15

Middle Cerebellar Peduncle (MCP)

Answer 15

Fibers from contralateral pontine nuclei that end as mossy fibers in all areas of cerebellar cortex.

Question 16

Facial nerve fibers

Answer 16

Most of them are on their way to ipsilateral muscles of facial expression and hook around the abducens nucleus before they leave the brainstem.

Question 17

Spinothalamic pathway

Answer 17

Mostly crossed fibers of second-order spinal neurons conveying pain and temperature information to the thalamus VPL, reticular formation, and midbrain. At this level, it also includes a contribution from the spinal trigeminal nucleus.

Question 18

Superior olivary nucleus

Answer 18

First site of convergence of fibers representing the two ears and the source of many of the fibers of the lateral lemniscus.

Question 19

Medial lemniscus

Answer 19

The principal ascending pathway for tactile and proprioceptive information. Originates in the contralateral posterior column nuclei and terminates in the thalamus (VPL).

Question 20

Trapezoid body

Answer 20

Crossing auditory fibers, primarily from the cochlear nuclei.

Question 21

Pontine nuclei and pontocerebellar fibers

Answer 21

Efferents from the cerebral cortex descend through the cerebral peduncle to reach ipsilateral pontine nuclei, whose axons cross in the basal pons and form the contralateral middle cerebellar peduncle (mossy fibers).

Question 22

Corticospinal, corticobulbar, and corticopontine fibers

Answer 22

No description.