Neuro Lecture 3 Flashcards
the corticospinal tract forms the ____ on the anterior aspect of the medulla and the ____ in the midbrain
pyramids; middle half of the cerebral peduncles
all brainstem levels rostral to the obex have 3 areas:
- tectum- posterior to ventricle
- tegmentum- anterior to ventricle
- stuff added anteriorly
the ____ has the most tectum
midbrain
the stuff added anteriorly has ____ functions and consists of what in each level?
conduit; cerebral peduncles in the midbrain, basal pons in the pons, and the pyramids and inferior olivary nucleus in the medulla
the tegmentum contains the ____ and ____ functions
Cranial nerve; reticular formation (integrative functions) of the brainstem
hypoglossal nerve (CN XII) rootlet exits medulla via ____, lateral to the pyramid
anterolateral sulcus or preolivary sulcus
rootlets of IX and X nerves exit the medulla via the ____, lateral to the olive
postolivary sulcus
tectum of the midbrain contains the ____ and ____
superior colliculus (rostral midbrain- visual function); inferior colliculus (caudal midbrain-auditory function)
markers of the caudal (closed) medulla
- central canal
- gracile and cuneate nuclei and tracts
- pyramidal decussation
markers of rostral (open) medulla
- fourth ventricle
- inferior olivary nucleus (in olive)
- XII nucleus
- pyramids
- medial lemniscus (feet down, vertically oriented)
markers of caudal pons
ICP
MCP
medial lemniscus- horizontal with feet down
fourth ventricle present
markers of rostral pons
SCP
medial lemniscus- horizontal with feet lateral, approaching STT
small ventricular space- opening of cerebral aqueduct
the _____ decussate in the caudal midbrain
superior cerebellar peduncles
after decussating, most SCP fibers end in the _____
red nucleus
nucleus that contains neurons that use dopamine as a neurotransmitter and heavily innervate the caudate and putamen of the cerebrum; neuronal loss results in parkinson’s disease
substantia nigra
caudal midbrain markers
inferior colliculi
CN IV nucleus
decussation of SCP
rostral midbrain markers
superior colliculi
red nucleus
substantia nigra
CN III nucleus
___ and ____ brainstem supplied by perforating branches
anterior; medial
____ supply lateral brainstem and cerebellum
circumferential arteries
the reticular formation extends into the cerebrum as the ____
hypothalamus
RF important in the regulation of:
- posture
- some stereotypic motor behaviors
- regulating internal environment
- pain regulation
- sleep and wakefulness
- emotional tone
most ascending and descending projections are in the ____ zone of the reticular formation
medial (paramedian)
lateral zone of RF is prominent in rostral medulla/caudal pons and is primarily involved in _____ and ____
cranial nerve reflexes; visceral functions
two reticulospinal tracts involved in movement control:
- medial (pontine) reticulospinal tract- from pontine RF to anterior horn
- lateral (medullary) reticulospinal tract- from medullary RF to anterior horn
brainstem RF gaze centers
- midbrain vertical gaze center
- pontine horizontal gaze center
pattern generator for mastication
supratrigeminal nucleus in the pons
locomotion pattern generator
in the pons
heart rate, respiration, swallowing/vomiting pattern generators
in the medulla “vital center”
PAG receives pain info from _____ fibers; also gets input from ____, ____ and ____
spinomesencephalic; hypothalamus, cortex, amygdala
one way opiates work to control pain is to activate ____ at multiple levels
PAG-raphe
opiate receptos abundant in ___, ____ and _____
PAG; raphe; posterior horn of spinal cord
raphe can inhibit ____ directly or indirectly by activating ____ that inhibit it. can also directly inhibit _____
STT; interneurons; pain afferents
midbrain and pons RF get input from multiple sensory modalities (i.e. pain, spinoreticular fibers); project to _____, which project diffusely to ____ to heighten arousal and consciousness
thalamic intralaminar nuclei; cortex
RF-thalamic intralaminar nuclear projections to cortex and _____ work together to modulate cortical activity
monoamine (serotonin and norepinephrine) reticular projections
RF maintains consciousness with the _____
ascending reticular activating system (ARAS)
chemicals in the BS
norepinephrine, serotonin, and dopamine
chemical in the hypothalamus
histamine containing neurons
chemical in the telencephalon
acetylcholine
noradrenergic neurons in the:
medulla and rostral pons
noradrenergic neurons in the medulla are in the ____ for _____ and in the ____ for _____
solitary nucleus; memory enhancement; ventrolateral medulla; pain regulation to the spinal cord
noradrenergic neurons in the rostral pons are in _____, which has projections to the cortex for _____
locus ceruleus; arousal/vigilance and attention
descending NE fibers to _____ and ascending NE fibers to _____
spinal trigeminal nucleus and spinal cord; all areas of cortex
clinical depression caused by:
decreased levels of NE; locus ceruleus neuron activity reduced
____ patients often suffer from depression bc locus ceruleus neurons are lost
parkinson’s disease
panic disorder caused by:
increased levels of norepinephrine
dopaminergic neurons in the _____
midbrain
dopaminergic neurons in the midbrain are in _____ and ______
substantia nigra (putamen and caudate); ventral tegmental area (limbic system)
2 components of ventral tegmental area dopaminergic projections
mesocortical fibers- organized thinking and planning; heavy projections to cortex
mesolimbis fibers- projections to amygdala, nucleus accumbens; emotional reward, drug dependency
low levels of dopamine in the prefrontal cortex causes:
social withdrawal (in schizophrenia)
high levels of dopamine in the limbic system causes:
hallucinations
drugs that ____ the level of dopamine are effective in reducing hallucinations
lower
serotonergic neurons located in pretty much all BS levels in _____
raphe
midbrain raphe nuclei to:
all regions of cortex
medullary raphe nuclei to:
spinal cord for pain suppression
low levels of serotonin characterized by
- high carb consumption
- binge eating
high levels of serotonin characterized by:
compulsive behavior and anorexia nervosa
drugs that increase levels of serotonin used to treat:
depression and anxiety
