Medulla HY Flashcards
characteristics of brainstem lesions
1) lesions of long tracts = contralateral deficit in body
2) Cranial Nerve signs reveal level of lesion in brainstem
3) Cranial nerve signs observed ipsilaterally
supply of blood to midbrain
posterior cerebral artery
supply of blood to pons
basilar artery
supply of blood to medulla
vertebral artery
cranial nerves originating from medulla
IX, X, XI, XII
9-12
cranial nerve motor nuclei of medulla – think of like _________
cranial nerve motor nuclei of medulla – think of like LMN
motor cranial nerve nuclei receive cortical input via _________ pathway
motor cranial nerve nuclei receive cortical input via CORTICOBULBAR pathway
(except eyes… TBD)
corticobulbar pathway receives ________ input
corticobulbar pathway receives BILATERAL input
except lower face… TBD
alar plate gives rise to _______
basal plate gives rise to _________
alar plate gives rise to SENSORY NEURONS
basal plate gives rise to MOTOR NEURONS
-separated by sulcus limitans
motor nuclei are ________ to sensory nuclei in brainstem
motor nuclei are MEDIAL to sensory nuclei in brainstem
motor - medial
sensory - lateral
medulla - columns of CN nuclei, from midline to lateral
MIDLINE
1) Somatic Motor - Hypoglossal Nuclei
2) Branchial Motor (pharyngeal) - Ambiguus Nuclei
3) Visceral Motor (Autonomic) - Dorsal Vagal Nuclei
4) Visceral Sensory - Solitarius Nuclei
5) Somatosensory - Spinal V nuclei
6) Special Senses - vestibular, cochlear nuclei
LATERAL
3 sections thru medulla
1) caudal medulla - motor crossing
2) caudal medulla - sensory crossing
3) rostral medulla
somatic motor column
Hypoglossal nucleus
- innervates intrinsic/extrinsic muscles of tongue
- most medial
hypoglossal lesion
- paralysis of tongue ipsilaterally
- fasciculations (LMN) ipsilaterally
- upon protrusion, tongue deviates to side of lesion
branchial motor column
Nucleus Ambiguus
- innervates larynx, pharynx, soft palate
- CN IX, X
- lateral?
nucleus ambiguus lesion
- hoarseness
- difficulty swallowing
- ipsilateral droop of arch of soft palate
- contralateral uvula deviation
visceral motor column
Dorsal Motor Nucleus of X
- preganglionic parasympathetics for thoracic and abdominal viscera
- medial (but just lateral to hypoglossal)
visceral sensory column
Nucleus Solitarius
- receives taste/sensation from viscera
- CN VII, IX, X
somatic sensory column
Spinal Nucleus of V
- pain/temperature from face
- lesion = ipsilateral deficit
- mostly CN V, but some VII, IX, X
lateral medullary lesion
-most common medullary lesion
LOSS OF NUCLEI:
- Solitarius: CN VII, IX, X
- —-taste/sensation from viscera
- Vestibular: CN VIII
- —–hearing (??)
- Spinal V: CN V (some VII, IX, X)
- —-ipsilateral deficit of pain/temperature
- Ambiguus: CN IX, X
- —-ipsilateral droop of soft palate arch
- —-contralateral uvula deviation
LOSS OF LONG TRACTS:
- STT (spinothalamic tract)
- —-contralateral deficit of pain/temperature
- ICP
- —–ipsilateral ataxia
- Reticular formation
- ——respiration, BP, HR
CN SIGNS
-X: parasympathetic to thoracic/abdominal viscera
medial medullary lesion
-other main medullary lesion
TRACTS LOST: Reticular Formation -respiration, BP, HR Medial Lemniscus -dorsal column pathway -position, vibration Corticospinal Tract -fine, distal movement
CRANIAL NERVE SIGNS CN XII: Hypoglossal -ipsilateral tongue paralysis -fasiculations -protrusion causes ispsilateral tongue deviation
reticular formation (location, function?)
medial
MEDULLA
- respiration
- BP
- HR
PONS/MIDBRAIN (additionally)
-arousal/consciousness
corticospinal tract (location?)
-always ventral
medial lemniscus (location?)
Dorsal Column Pathway
- medial
- midline medulla: vertical
- as it travels up, it becomes more horizontal, joins with spinothalamic pathway
