Lab Section 5

Question 1

what deficits are most helpful for localizing medulla pathology?

Answer 1

cranial nerve signs (because they are segmental)

Question 2

which cranial nerves and nuclei are associated with the medulla?

Answer 2

CN VIII-XII

Question 3

what autonomic functions are regulated in the medulla?

Answer 3

respiration, blood pressure and cardiac rhythm

Question 4

which cranial nerves supply the spinal nucleus of the trigeminal nerve with sensory information?

Answer 4

CN 5,7,9 and 10

Question 5

what is the medulla called while it still contains the central canal as its lumen?

Answer 5

the closed medulla

Question 6

portions of the ventral horn remain as what nucleus? what landmarks mark this change?

Answer 6

accessory nucleus CN XI

present when the pyramids are deccusating

Question 7

which two structures exist throughout the brainstem and at which myelin section do they begin?

Answer 7

the medial longitudinal fasciculus and the reticular formation
they begin at the second section of the medulla

Question 8

what does the MLF do? what does it connect?

Answer 8

it coordinates head and eye movements

connects the superior colliculus, the vestibular nuclei, CN nuclei III, IV and VI and the cervical spinal cord

Question 9

where is the MLF most prominent?

Answer 9

in the more rostral areas of the brainstem where the extraocular motor nuclei lie

Question 10

what does the reticular formation do around the areas of the cranial nerve nuclei?

Answer 10

coordinates reflexes and simple stereotyped responses mediated by the cranial nerves

Question 11

what is the reticular formation generally involved with?

Answer 11

modulating different functions such as movement, posture, arousal, sleep, awakening, pain control and autonomic function

Question 12

what are the raphe nuclei?

Answer 12

serotenergic neurons along the midline for the entire brainstem (involved in pain modulation)

Question 13

where is the spinal nucleus of the trigeminal nerve present? which portion of the nucleus is involved with protopathic and which is related to epicritic sensation?

Answer 13

in both the pons and medulla

protopathic: medulla
epicritic: pons

Question 14

which two muscles are innervated by the accessory nerve and nucleus?

Answer 14

the trapezius and sternocleidomastoid

Question 15

what happens to the corticospinal tract in the medulla?

Answer 15

first traveling as the pyramids, it crosses at the decussation of the pyramids and continues down from there

Question 16

what structures involved with epicritic sensation of the body appears in the medulla? what do they look like in the external anatomy?

Answer 16

the gracile and cuneate nuclei (dorsal column nuclei)

bumps on the dorsal medulla are the gracile and cuneate tubercles

Question 17

at which level do the gracile and cuneate fasciculi disappear? the nuclei?

Answer 17

gracile: fasciculus ends at the second medullary section with the nucleus in the following section
cuneate: fasciculus ends in the same section as the gracile nucleus and the nucleus at the next level

Question 18

what happens to the epicritic information rostral to the dorsal column nuclei?

Answer 18

they cross as the internal arcuate fibers and arise as the medial lemniscus just rostral to the decussation of the pyramids

Question 19

describe the somatotopy of the medial lemniscus

Answer 19

neck to foot somatosensory info is mapped from dorsal to ventral

Question 20

when does the medial lemniscus move from its midline position?

Answer 20

at the junction between the medulla and the pons

Question 21

what 6 cerebellar related structures are seen in the medulla?

Answer 21

the inferior cerebellar peduncle, the accessory cuneate nucleus, the dorsal spinocerebellar tract, the inferior olives, the vestibular nuclei and the cuneocerebellar tract

Question 22

at what level can the accessory cuneate nucleus be found?

Answer 22

the third level up in the medulla (right when it opens up)

Question 23

where can the hypoglossal nucleus be found?

Answer 23

dorsal to the medial lemniscus from the end of the open medulla to the most caudal section of the medulla

Question 24

how does the tongue protrude if CN XII is damaged unilaterally? if the UMN is damaged (rostral to the medulla)?

Answer 24

cranial nerve: towards the lesion (protrusion muscle deficit)
UMN: away from the lesion (crossed circuit)

Question 25

what type of neurons are in the nucleus ambiguus? where do they project mainly?

Answer 25

motor neurons to the larynx and pharynx projecting to CN IX and X

Question 26

if the nucleus amgiguus is damaged, what are the symptoms?

Answer 26

hoarseness, impaired swallowing and asymmetry of the soft palate

Question 27

what types of neurons are within the dorsal motor nucleus of the vagus?

Answer 27

preganglionic parasympathetic neurons of the vagus nerve

Question 28

what does the solitary tract and its nucleus receive?

Answer 28

afferent info from the pharynx, larynx, cardiovascular system and gastrointestinal system (CN 7, 9 and 10)
rostral pole receives taste from the tongue

Question 29

when do cranial nerve IX-XII nuclei disappear?

Answer 29

in the vestibular area/nuclei appear more rostrally

Question 30

how many vestibular nuclei are there? what are their purpose?

Answer 30

4

mediate vestibular reflexes and to send information to the cerebellum (ICP)

Question 31

what do the salivatory nuclei do? where is it located?

Answer 31

send axons to the ganglia of the salivary glands (CN 7 and 9)
located in the rostral medulla

Question 32

where are the cochelar nuclei located?

Answer 32

on the external surface of the inferior cerebellar peduncle at the junction between the medulla and the pons

Question 33

what are the CN VIII signs?

Answer 33

deafness in ipsilateral ear, nystagmus, vertigo and balance problems

Question 34

what are CN IX signs?

Answer 34

loss of gag reflex on the ipsilateral side

Question 35

what are CN X signs?

Answer 35

hoarseness, difficulty swallowing, assymmetry of the soft palate.
bilateral- chcoking and loss of parasympathetic control to the heart and GI tract

Question 36

what are CN XI signs?

Answer 36

inability to elevate ipsilateral shoulder and difficulty to turn and tilt the head away from the lesion

Question 37

what are CN XII signs?

Answer 37

paralysis of ipsilateral tongue muscles; deviation towards the side of the weakness with fasciculations and atrophy

Question 38

what structures in the medulla are supplied by the anterior spinal artery? what would damage cause?

Answer 38

the hypoglossal nucleus, medial lemniscus and pyramids

paresis and loss of epicritic sensation of the body and tongue deviation ipsilaterally

Question 39

what structures in the medulla are supplied by vertebral branches?

Answer 39

ALS and part of the inferior olive

Question 40

what structures in the medulla are supplied by PICA?

Answer 40

Spinal nucleus and tract of V, inferior cerebellar peduncle, nucleus ambiguus, solitary nucleus and tract, dorsal motor nucleus of X and vestibular nuclei

Question 41

what structures in the medulla are supplied by AICA?

Answer 41

the rostral medulla: corticospinal tract, medial lemniscus, and MLF

Question 42

what structures in the medulla are supplied by basilar branches?

Answer 42

the vestibular nuclei and the vestibulocochlear nerve