Brainstem; Pons

Question 1

pontine fibers; origin, path, termination

Answer 1

originate in pontine nucleus
cross the midline 
form midd cerebellar peduncle
terminate in the cerebellum
Role: relay info fr the cerbral cortex to the cerebellum

Question 2

longitudinal pontine motor fibers; contain?

Answer 2

corticospinal and Corticopontine fibers

also is known as the pyramidal tract

Question 3

unilateral lesion of longitudinal pontine motor fibers (above pyramidal decussation)

Answer 3

contralat motor deficit

Question 4

dorsal portion of the pons

Answer 4

pontine tegmentum
contains ascending and descending tracts
components of several cranial nerves

Question 5

unilateral lesion of medial lemniscus at caudal pons

Answer 5

contralat loss in proprioception and fine touch sensation from body

Question 6

fibers that enter the cerebellum via the SCP

Answer 6

ventral spinocerebellar tract VSCT

Question 7

where do SCP fibers cross?

Answer 7

more rostrally in the caudal midbrain at the decussation of the superior cerebellar peduncles

Question 8

trapezoid body

Answer 8

fibers crossing fr cochlear nuclei to the contralat Sup Olivary Nucleus
sound localization

Question 9

facial colliculus

Answer 9

formed by the facial motor nucleus fibers looping over the abducens nucleus

Question 10

facial motor nucleus

Answer 10

MN innerv skel mm of facial expression

form internal genu that loops over abducens nuc

Question 11

lesion of facial nerve

Answer 11

paralysis of mm of facial exp
hyperacusis - over sensitivity to sound
*loss of lacrimation & salivation
*loss of taste in ant 2/3 of tongue
loss of blink reflex (motor limb)
*means nerve lesion not just nuclei

Question 12

lesion of facial nucleus only

Answer 12

paralysis of mm of facial expresion
hyperacusis - oversensitivity to sound
loss of blink reflex

Question 13

abducens nerve emerges, and innervates

Answer 13

emerges bet pons and pyramid of medulla

innervates the lateral rectus mm

Question 14

lesion of abducens nerve

Answer 14

medial deviation of ipsilat eye

Question 15

lesion of abducens nucleus

Answer 15

medial deviation of ipsilat eye

inability to adduct contralat eye during horizontal gaze to lesioned side

Question 16

lesion of spinal nucleus and tract of V

Answer 16

ipsilat loss of pain & temp sens from face

loss of blink reflex (afferent limb)

Question 17

superior olivary complex involved in

Answer 17

sound localization

Question 18

paramedian pontine reticular formation (PPRF)

Answer 18

in pontine tegmentum near abducens nuc

imp for coordination of horizontal gaze

Question 19

pontine reticulospinal tract (PRST) main function

Answer 19

facilitate extensor motor neurons

Question 20

lesion of the PPRF

Answer 20

deficits in horizontal gaze

Question 21

transverse pontine fibers major function

Answer 21

cont to motor planning, timing, and coordination of movements

Question 22

route of transverse pontine fibers

Answer 22

origin pontine nuclei, cross the midline, form Midd cerebellar peduncle, terminate in the cerebellum
relay info from cerebral cotex to cerebellum

Question 23

unilat lesion of descending longitudinal pontine motor fibers in the mid pons

Answer 23

contralat motor deficit in body

contralat drooping of the corner of the mouth

Question 24

unilat lesion of the medial lemniscus in the mid pons

Answer 24

contralat loss in prop and fine touch sensation from the body and FACE

Question 25

termination pt of axons in the medial lemniscus carrying info from the body

Answer 25

Ventral Posterior Lateral nucleus (VPL) of the thalamus

Question 26

axons in the medial lemniscus carrying info from the face terminate in the

Answer 26

Ventral Posterior Median nucleus (VPM) of the thalamus

Question 27

the ascending medial longitudinal fasciculus (MLF) connects the vestibular nuclei with the nuclei of the….

Answer 27

abducens
trochlear
oculomotor nerves;
circuitry for the vestibulo-ocular reflex (VOR)

Question 28

unilat lesion of the MLF bet the abducens nucleus and oculomotor nucleus

Answer 28

internuclear ophthalmoplegia (impairment of adduction of the affected eye)

Question 29

unilateral lesion of SCP

Answer 29

ipsilateral ataxia (lack of control vol mvmt)
hypotonia
dysmetria (lack of coordination of mvmt)

Question 30

lesion of motor nucleus of V

Answer 30

paralysis and atrophy of the mm of mastication

mandible deviates to affected side

Question 31

mesencephalic nuc of V

Answer 31

primary sensory neurons (pseudounipolar)

innerv masseter mm spindle => afferent limb of the jaw jerk reflex

Question 32

lesion of the mesencephalic nucleus of V

Answer 32

loss of jaw jerk reflex (afferent limb)

Question 33

chief (main) sensory nucleus of V - info

Answer 33

ipsilat epicritic sens from face
via 3 sens br of trigeminal
1st ganglion in the trigeminal ganglia

Question 34

path of epicritic info from face

Answer 34

3 sens br of trig -> trig ganglia -> chief sens nuc of V - decussates -> medial lemniscus -> ascends to VPM thalamus (3rd neuron) -> somatosensory cortex

Question 35

lesion of chief sensory nuc of V

Answer 35

ipsilat loss of epicritc sens from face

Question 36

lesion of trigeminal nerve

Answer 36

loss of blink reflex (sensory limb)
ipsi loss of gen sensation (epi&proto) from face and scalp
jaw deviation toward lesion

Question 37

pontine reticulospinal tract (PRST), origin, termination, function

Answer 37

originates in nuc reticularis pontis caudalis oralis in pontine reticular formation
terminates; spinal cord
function; fac ext MN