3 PONS

Question 1

What are the two major regions of the pons?

Answer 1

tegmentum and basis pontis

Question 2

what does basis pons contain

Answer 2

• corticopontine and pontocerebellar fibers

- PONTINE NUCLEI

Question 3

pons is derives from which latin word?

Answer 3

bridge

Question 4

What does the pontine tegmentum contain?

Answer 4

CN nuclei and major ascending/descending tracts

Question 5

which CN nuclei does the tegmentum contain? motor and sensory

Answer 5

motor=VII, VI, and V

sensory= VIII V

Question 6

What is the major internuclear tract found in the pontine tegmentum?

Answer 6

medial longitudinal fasciculus (MLF)

Question 7

What are the major ascending tracts of the pontine tegmentum?

Answer 7

medial lemniscus
trigemino-thalamic
spinothalamic

Question 8

The facial nucleus contains what type of branchiomotor neurons?

Answer 8

SVE- migrates away from floor of 4th ventricle

Question 9

T-F– axons of the facial nucleus wrap around the lateral edge of the abducens nucleus

Answer 9

false- medial edge

Question 10

Do lesions of the abducens nucleus often damage CNVII fibers?

Answer 10

YES

Question 11

The rostral end of the spinal nucleus and tract of V is in the caudal pons, afferent endings here are mostly what types of sensations?

Answer 11

crude touch from face and cornea

Question 12

ParaSNA nuclei (GVE) in the pons include what?

Answer 12

superior salivatory nucleus and inferior salivatory nucleus

Question 13

As the basis pontis swells what happens to medial lemniscus?

Answer 13

flattens out and inferior portion lies laterally

Question 14

T-F—the caudal part of the solitary nucleus receiving taste is in the caudal pons?

Answer 14

false, rostral part in the caudal pons

Question 15

What does spinal trigeminal tract carry at the pontine level?

Answer 15

primary afferents simple touch from face

Question 16

2nd order fibers of the spinal trigeminal cross midline and ascend as what?

Answer 16

ventral trigeminothalamic tract

Question 17

What receives discriminative touch sensation from the head and face?

Answer 17

main sensory nucleus of V

Question 18

What 2nd order neuron carries conscious proprioception, vibratory sensation, and discriminative touch from the contralateral body?

Answer 18

medial lemniscus

Question 19

T-f—2nd order tract fibers carrying pain, temp and simple touch from contralateral body pass through the basis pontines?

Answer 19

false- pass through pontine tegmentum

Question 20

What in the pons connects the III, IV and VI nuclei with themselves and with the vestibular nuclei?

Answer 20

medial longitudinal fasciculus

Question 21

What connects the abducens and oculomotor nuclei to enable lateral conjugate gaze?

Answer 21

MLF

Question 22

What is the gray matter component in the basis pontis?

Answer 22

pontine nuclei

Question 23

What is the largest input into the cerebellum?

Answer 23

middle cerebellar peduncle- (axons of neurons in the pontine nuclei cross middling to enter this)

Question 24

Where do corticonuclear fibers to V, VI and VII nuclei enter the tegmentum?

Answer 24

upper pons

Question 25

What do the pontine nuclei receive signals from?

Answer 25

every area of the ipsilateral cortex via cortico-pontine fibers

Question 26

Do pontocerebellar fibers enter the opposite cerebellum?

Answer 26

yes

Question 27

What reflex is mainly used to test the integrity of the pons?

Answer 27

corneal reflex

Question 28

Nociception from the cornea is carried by what type of fibers?

Answer 28

Asigma and C fibers from long ciliary branches of V1

Question 29

Is the corneal reflex consensual?

Answer 29

yes

Question 30

What 3 major groups of vessels supply the pontine region from the basilary artery?

Answer 30

- paramedian (medial part of basis and tegmentum) - short circumferential (ventrolateral basis pontis only) - long circumferential-[AICA- superior cerebellar arteries] (lateral and dorsal pontine tegmentum)

Question 31

Lesion of the abducens nerve produces what?

Answer 31

ipsilateral lateral rectus palsy

Question 32

Lesions of the abducens nucleus produces what?

Answer 32

paralysis of lateral conjugate gaze on side ipsilateral to the lesion

Question 33

Lesions of the MLF produce what?

Answer 33

look opposite of lesion- ipsilateral adducting eye cannot adduct while contralateral eye can abduct

Question 34

Lesions involving facial nerve or nucleus produce?

Answer 34

LMN signs ipsilateral to side of lesion affect upper and lower face

Question 35

T-F---the lower face receives UMN bilaterally?

Answer 35

False- contralateral (upper face receives bilayer)

Question 36

Unilateral UMN VII lesions produce what?

Answer 36

contralateral lower face paralysis

Question 37

Tegmental pontine syndromes are characterized by?

Answer 37

ipsilateral CN signs and contralateral sensory loss over body

Question 38

What syndrome- bilateral corticobulbar fibers to CN motor nuclei, UMN weakness, speeach problems, dysphagia, inappropriate outbursts of laughter/crying, emotional input is preserved?

Answer 38

pseudo bulbar palsy

Question 39

What syndrome--caudal basal pontine lesion of VI and VII. Crossed hemiplegia with ipsilateral LMN signs in head and contralateral signs in body?

Answer 39

millard-grubler

Question 40

What syndrome- contralateral UMN to the body and ipsilateral CN signs?

Answer 40

basal pontine syndromes

Question 41

What syndrome--rostral pontine tegmental lesion with VI nerve palsy and conjugate gaze palsy, dysarthria and contralateral hemianesthesia?

Answer 41

raymond-cestan

Question 42

what syndrome-- facial expression, speech and movement affected. somatosensory is sparred so patient is awake and aware. eye movements may also be spared?

Answer 42

Locked-in syndrome- large lesions of the basal pons damaging the corticospinal and corticobulbar pathways.