Flashcards in 3 PONS Deck (42):
What are the two major regions of the pons?
tegmentum and basis pontis
what does basis pons contain
-corticopontine and pontocerebellar fibers
- PONTINE NUCLEI
pons is derives from which latin word?
What does the pontine tegmentum contain?
CN nuclei and major ascending/descending tracts
which CN nuclei does the tegmentum contain? motor and sensory
motor=VII, VI, and V
sensory= VIII V
What is the major internuclear tract found in the pontine tegmentum?
medial longitudinal fasciculus (MLF)
What are the major ascending tracts of the pontine tegmentum?
The facial nucleus contains what type of branchiomotor neurons?
SVE- migrates away from floor of 4th ventricle
T-F-- axons of the facial nucleus wrap around the lateral edge of the abducens nucleus
false- medial edge
Do lesions of the abducens nucleus often damage CNVII fibers?
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?
crude touch from face and cornea
ParaSNA nuclei (GVE) in the pons include what?
superior salivatory nucleus and inferior salivatory nucleus
As the basis pontis swells what happens to medial lemniscus?
flattens out and inferior portion lies laterally
T-F---the caudal part of the solitary nucleus receiving taste is in the caudal pons?
false, rostral part in the caudal pons
What does spinal trigeminal tract carry at the pontine level?
primary afferents simple touch from face
2nd order fibers of the spinal trigeminal cross midline and ascend as what?
ventral trigeminothalamic tract
What receives discriminative touch sensation from the head and face?
main sensory nucleus of V
What 2nd order neuron carries conscious proprioception, vibratory sensation, and discriminative touch from the contralateral body?
T-f---2nd order tract fibers carrying pain, temp and simple touch from contralateral body pass through the basis pontines?
false- pass through pontine tegmentum
What in the pons connects the III, IV and VI nuclei with themselves and with the vestibular nuclei?
medial longitudinal fasciculus
What connects the abducens and oculomotor nuclei to enable lateral conjugate gaze?
What is the gray matter component in the basis pontis?
What is the largest input into the cerebellum?
middle cerebellar peduncle- (axons of neurons in the pontine nuclei cross middling to enter this)
Where do corticonuclear fibers to V, VI and VII nuclei enter the tegmentum?
What do the pontine nuclei receive signals from?
every area of the ipsilateral cortex via cortico-pontine fibers
Do pontocerebellar fibers enter the opposite cerebellum?
What reflex is mainly used to test the integrity of the pons?
Nociception from the cornea is carried by what type of fibers?
Asigma and C fibers from long ciliary branches of V1
Is the corneal reflex consensual?
What 3 major groups of vessels supply the pontine region from the basilary artery?
-paramedian (medial part of basis and tegmentum)
-short circumferential (ventrolateral basis pontis only)
-long circumferential-[AICA- superior cerebellar arteries] (lateral and dorsal pontine tegmentum)
Lesion of the abducens nerve produces what?
ipsilateral lateral rectus palsy
Lesions of the abducens nucleus produces what?
paralysis of lateral conjugate gaze on side ipsilateral to the lesion
Lesions of the MLF produce what?
look opposite of lesion- ipsilateral adducting eye cannot adduct while contralateral eye can abduct
Lesions involving facial nerve or nucleus produce?
ipsilateral to side of lesion
affect upper and lower face
T-F---the lower face receives UMN bilaterally?
False- contralateral (upper face receives bilayer)
Unilateral UMN VII lesions produce what?
contralateral lower face paralysis
Tegmental pontine syndromes are characterized by?
ipsilateral CN signs and contralateral sensory loss over body
What syndrome- bilateral corticobulbar fibers to CN motor nuclei, UMN weakness, speeach problems, dysphagia, inappropriate outbursts of laughter/crying, emotional input is preserved?
pseudo bulbar palsy
What syndrome--caudal basal pontine lesion of VI and VII. Crossed hemiplegia with ipsilateral LMN signs in head and contralateral signs in body?
What syndrome- contralateral UMN to the body and ipsilateral CN signs?
basal pontine syndromes
What syndrome--rostral pontine tegmental lesion with VI nerve palsy and conjugate gaze palsy, dysarthria and contralateral hemianesthesia?