Neuroanat wk 3 Flashcards
disruption in the corticospinal tract in the pyramids superior to decussation via injury to the anterior spinal artery could cause…
inferior alternating hemiplegia
How does inferior alternating hemiplegia present?
ipsilateral tongue deficit and contralateral limb paralysis
Vertebral arteries on the anterior surface of the medulla split into what three vessels?
anterior spinal artery dorsal spinal arteries posterior inferior cerebellar arteries
What artery follows in the inferior pontine sulcus then middle cerebellar peduncle?
anterior inferior cerebellar arteries
What artery, after branching off of the rostral part of the basilar artery will deflect caudally following the superior peduncle?
superior cerebellar artery
The posterior spinal artery will give blood flow to what areas?
gracile fasciculus and cuneate fasciculus
Does the hypoglossal nucleus decussate? What is its path/where is it located?
no - extends as a series of nerve rootlets, seen internally in open medulla along lateral surface of medial lemniscus then b/t pyramids and inferior olive body to emerge in ventrolateral sulcus of medulla
What artery always has its perfusion zone lateral to midline?
vertebral artery
Medial medullary syndrome occurs when the anterior spinal artery is compromised, affecting mostly the…
pyramidal system combo’d with impact on the hypoglossal nuc.
What is the MC form of brain stem stroke?
PICA stroke/Wallenberg syndrome/lateral medullary syndrome
What are structures along the floor of the fourth ventricle starting at midline and going laterally?
hypoglossal nuc dorsal longitudinal fasciculus dorsal motor nuc of vagus solitary nuc vestibular nuc
What is between the vestibular nucleus and the inferior cerebellar peduncle in the rostral medulla?
accessory cuneate nuc
neurons from the superior and medial vestibular nuclei five rise to axons that ascend to synapse on the 3 motor nuc of… where are they?
extraocular muscles abducent in pons trochlear and oculomotor in midbrain
vestibular nuclei send their axons via… to adjust eye gaze for changes in head position
MLF - medial longitudinal fasciculus
What receives input from CN VII, the inferior and superior glossopharyngeal ganglia, and the vagus nerve? What does this area control?
rostral portion of solitary nucleus input for taste sensation/gustatory
Spinal nucleus of trigeminal receives pain input from what two nerves?
glossopharyngeal inf and sup nuclei vagus nerve
What is in charge of visceral sensation received from VII, IX, and X?
caudal portion of solitary nucleus
Parasympathetic axons within CN IX originate in the …. and … in order to provide LMN to skeletal muscles of pharynx and larynx
inferior salivatory nucleus and nucleus ambiguus
Where do pre-ganglionic parasympathetic fibers of CN X originate?
dorsal motor nuc of vagus nucleus ambiguus for cardiac fibers
What makes the nucleus ambiguus unique?
it has parasympathetic fibers along with LMN fibers originating there
What is the pathway of the gag reflex?
- sensation in pharynx
- afferents through IX
- spinal trigeminal sensory neuron
- caudal solitary nucleus
- Nucleus Ambiguus
- trigeminal motor nuc
- LMN - open mouth
- hypoglossal nuc
- LMN protract tongue
- LMN - constrict pharynx
- trigeminal motor nuc
- Nucleus Ambiguus
- afferents through IX
Locked-In Syndrome is a result of what kind of lesion?
Basilar artery Thrombosis
Roughly, the ventral brainstem is responsible for… while the dorsal brainstem is responsible for…
motor
sensory
AICA strokes usually cause ipsilateral facial paralysis because it affects the …
trigeminal motor nucleus
AICA strokes could cause alternating facial and body analgesia due to injury to…
spinothalamic and descending trigeminal spinal sensory tract
AICA strokes if affecting the lateral lemniscus could cause… while if affecting the MLF it could cause…
deafness
nystagmus