Caudal Pons And Pontomedullary Jxn

Front 1

where do the pontine nuclei migrate from? where do they go to?

Back 1

from: part of the alar plate ventrally and medially
to: form the basilar pons.

Front 2

what will the axons from the migrated pontine nuclei form?

Back 2

the middle cerebellar peduncle that wraps around the brainstem in a lateral position

Front 3

In the development of the pons, what does the basal plate form?

Back 3

the midline and dorsal motor components of cranial nerve nuclei

Front 4

what is the pontine tegmentum a rostral continuation of?

Back 4

medullar reticular formation and associated tracts.

Front 5

what is contained in the pontine tegmentum?

Back 5

pontine cranial nerve nuclei and ascending sensory tracts

Front 6

what two tracts run through the basilar pons?

Back 6

corticobulbar and corticospinal

Front 7

In the pons, where is the pontine cranial nerve nuclei located? where is the pontine nuclei located?

Back 7

pontine cranial nerve nuclei - pontine tegmentum
pontine nuclei- basilar pons

Front 8

at what level in the pons is the Cochlear component of CN 8 located?

Back 8

ponto medullar junction

Front 9

where are the cell bodies of origin located for the cochlear component?

Back 9

dorsal cochlear nucleus and ventral cochlear nucleus

Front 10

Do the cochlear component fibers cross? if so, where?

Back 10

yes: primarily at more rostral levels in the trapezoid body and in the dorsal and intermediate acoustic stria.

Front 11

which number labels the trapezoid body?

Back 11

8

Front 12

what number labels the nucleus of the trapezoid body?

Back 12

9

Front 13

what is the origin of the efferent cochlear bundle?

Back 13

superior olivary nucleus

Front 14

what reflex is the superior olivary nucleus involved in? Via which CN?

Back 14

reflex for sound dampening via CN 7 (stapedius)

Front 15

in the ponto medullary junction, what is included in the central processing nuclei?

Back 15

nucleus of the trapezoid body, superior olivary nucleus and nucleus of the lateral lemniscus.

Front 16

Name the colored parts.

Back 16

red: superior olivary nucleus
orange: nucleus of the trapezoid body.

Front 17

Axons from the central processing nuclei collect primarily where?

Back 17

in the contralateral lateral lemniscus.

Front 18

Where do the axons from the central processing nuclei ascend to? (3)

Back 18

inferior colliculus, medial geniculate body (thalamus),, and Cortex (temporal, transvers gyri of Heschel).

Front 19

what is the function of the transverse gyri of heschel?

Back 19

conscious perception

Front 20

why doesn't an ipsilateral lesion cause a hearing loss (usually)? what are the exceptions?

Back 20

because the lateral lemniscus travels bilaterally with a contralateral predominance.
exceptions: the nerve or cochlear nuclei are involved.

Front 21

how many nuclei are innervated by the vestibular component of the vestibulocochlear nerve? what are they?

Back 21

4;medial vestibular, lateral vestibular (deiter's), superior vestibular, and inferior vestibular.

Front 22

how do the projections of the vestibular nuclei reach the cerebellum?

Back 22

via the justarestiform body located in the lateral vestibular nucleus.

Front 23

T/F
There are some direct connection of the vestibulocochlear nerve to the flocculonodular lobe.

Back 23

TRUE!

Front 24

what is the function of the juxtarestiform body?

Back 24

balance coordination

Front 25

what are the two vestibular related nuclei/ structures?

Back 25

oculomotor nuclei and thalamus

Front 26

Via what structure do the vestibular related pathways have an impact on balance? how?

Back 26

Both are via the medial longitunal fasciculus.
Thalamus: Projects to cortex to give conscious perception of equilibrium and orientation

Front 27

what 2 tracts relates the vestibular pathway and the spinal cord?

Back 27

lateral vestibulospinal tract and medial vestibulospinal tract

Front 28

what is another name for the medial vestibulospinal tract?

Back 28

Medial longitudinal fasciculus

Front 29

what is the function of the medial vestibulospinal tract?

Back 29

inhibitory to neck and upper trunk muscles; contributes to head-righting reflexes in relation to vision

Front 30

Besides CN 8, the caudal pons conatins the nuclei for which two CNs?

Back 30

6 and 7

Front 31

where does the facial nerve exit the brainstem?

Back 31

just anterior to CN 8 at pontomedullar junction

Front 32

describe the course of the facial nerve.

Back 32

axons loop around the nucleus of CN 6 and exit ipsilaterally.

Front 33

what indicates the presence of the abducens nucleus?

Back 33

the bump on the floor of the 4th ventricle

Front 34

what surrounds the abducens nucleus?

Back 34

facial colliculus (facial fiber axons)

Front 35

are the axons that form the loop in the pathway of the facial nerve primarily sensory or motor?

Back 35

motor

Front 36

Name the colored area.

Back 36

Facial colliculus

Front 37

how does cortical innervation from the facial nerve differ when innervating muscles of the forehead vs muscles of the lower face?

Back 37

bilateral innervation to the muscles of the forehead, contralateral to muscles for the lower face.

Front 38

If there is a lesion of the motor nucleus in the pons, what kind of paralysis should we find of the facial muscles?

Back 38

ipsilateral forehead paralysis, contralateral paralysis to mouth and chin.

Front 39

what kind of fibers does the intermedius branch of the facial nerve contain?

Back 39

GVE (parasympathetic functions), SVA and GSA

Front 40

For the parasympathetic aspect of the intermedius branch of the facial nerve, which nuclei is involved?

Back 40

superior salivatory nucleus

Front 41

detail the pathway that starts at the limbic system and affects the intermedius branch of the facial nerve resulting in weeping and mouth watering to odors.

Back 41

limbic system and olfactory areas through hypothalamus to the brainstem via the dorsal longitudinal fasciculus.

Front 42

signals from the brainstem on the intermedius branch of the facial nerve result in?

Back 42

reflex lachrymation and gustatory stimulation of salivation

Front 43

describe the pathway of the solitary nucleus (specifically gustatory nucleus). Detail it from mouth to cortex.

Back 43

Begins with sensory fibers from taste buds on tongue and hard and soft palates that run in chorda tympani from geniculate ganglion. Then it will project into the brainstem as intermedius nerve and enter the tractus soliatrius to synapse in the rostral portion of the nucleus. The nucleus then sends the info via the central tegmental tract to the thalamus which projects it to cortex.

Front 44

which portion of the solitary nucleus is specifically for gustatory nucleus?

Back 44

rostral portion

Front 45

what tract is used by the solitary nucleus to project taste fibers to the thamalus?

Back 45

central tegmental tract

Front 46

which part of the thalamus are the taste fibers from the solitary nucleus projected too?

Back 46

ventral posteromedial

Front 47

what two parts of the ear are innervated by the intermedius nerve?

Back 47

skin of the ear wall of acoustic meatus and external tympanic membrane.

Front 48

what nucleus supplies the GSA for the intermedius nerve?

Back 48

spinal trigeminal nucleus

Front 49

what is the pathway of the GSA fibers of the intermedius nerve?

Back 49

axons innervating areas around ear enter brainstem in the nervous intermedius and descend in spinal tract of trigeminal to synapse at the spinal V nucleus.

Front 50

Label each nervous intermedius colored tract with the appropriate fiber (GSA, GVE, etc)

Back 50

Red: GVE
purple: SVA
blue: GSA

Front 51

via what sulcus does the abducens nerve exit?

Back 51

inferior pontine

Front 52

what is the function of the abducens nerve?

Back 52

motor innervation to ipsilateral lateral rectus muscle of the eye.

Front 53

what is one of the most frequently injured CN that also has a long intracranial course?

Back 53

abducens nerve

Front 54

what nuclei does the abducens nerve have a complex central connection?

Back 54

oculomotor nuclei

Front 55

What CN exhibits this path?

Back 55

abducens

Front 56

how does the abducens nerve interact with the oculomotro nucleus?

Back 56

via medial longitudinal fasciculus

Front 57

what do the rostral projections of the reticular formation regulate? where do they project to?

Back 57

regulate consciousness and caudal projections (thalamus).

Front 58

what do the caudal projections of the reticular formation regulate?

Back 58

motor and sensory functions

Front 59

what two tracts run through the substance of the basilar pons?

Back 59

corticospinal and corticonuclear tracts

Front 60

label all of the colored nuclei.

Back 60

:)

Front 61

at what level in the brainstem does the medial lemniscus reach its midline position?

Back 61

Medulla Levels (after medulla-pons junction)

Front 62

In the pons, are the major tracts located?

Back 62

caudal pons.

Front 63

what tract alway runs in tandem with the ALS?

Back 63

rubrospinal tract

Front 64

name the three subdivision of the trigeminal nucleus. which one is most rostral? most caudal?

Back 64

pars oralis (rostral), pars interpolaris, pars caudalis (caudal).

Front 65

which subdivision of the trigeminal nucleus are you most likely to see at the region of the caudal pons?

Back 65

pars oralis.

Front 66

what are the major tracts that enter the cerebellum beginning at the pontomedullary junction?

Back 66

inferior cerebellar peduncle (restiform body) enters the cerebellum with vestibulocerebellar projections (juxtarestiform body)

Front 67

which tract wraps latterally around the inferior peduncle at the pontomedullar junction?

Back 67

middle cerebellar peduncle

Front 68

Name the colored regions. What part of the brainstem is this?

Back 68

pontomedullar junction

Front 69

what two structures make up the roof of the fourth ventricle?

Back 69

superior cerebellar peduncles and superior medullar velum

Front 70

what is the blood supply to the pontomedullary junction and caudal pons?

Back 70

vertebral arteries, basilar artery, posterior inferior cerebellar artery, anterior inferior cerebellar arteries.

Front 71

What is the major blood supply to just the pontomedullary junction?

Back 71

vertebral, medial branches of the basilar and posterior inferior cerebellar artery.

Front 72

what is the major blood supply to just the caudal pons?

Back 72

branches of the basilar artery: paramedian, and short and long circumferential branches.
May also be supplied by anterior inferior cerebellar artery.