Exam 2 Content Week 3 Flashcards
what cranial nerves comes out of what parts of the brainstem
midbrain (3 and 4)
pons (5-8)
medulla (9,10,12)
where is the 4th ventricle
between the pons and the cerebellum
what is the reticular formation
in the brainstem, it
- integrates sensory and cortical information
- regulates somatic motor activity (reticulospinal) and ANS
- regulates sleep and consciousness
- modulates nocioceptive information
what are the 4 reticular nuclei
ventral tegmental area
pedunculopontine nucleus
locus coeruleus
rahphe nuclei
describe the NT/MN and function of the VTA
dopamine
responsible for reward seeking behavior and motivation and decision making.
When too much activity: addiction, schizophrenia
describe the NT/MN and function of the PPN
ACh
influences movement, like walking and gait. With Parkinson’s you loss this, so you get decreases in movement, sleep issues and cannot initiate walking.
describe the NT/MN and function of the locus coeruleus
NE
directs attention. so when it is active, we can pay attention
describe the NT/MN and function of the raphe nuclei
serotonin
mood!
antidepressants prolong the serotonin in the junction, so it inhibits the re-uptake
which part of the brainstem are the reticular nuclei
rostral part
what is the ascending reticular activating system
ARAS project to the thalamic nuclei, then project to the cortex.
regulates sleep/wake cycles, and consciousness (self awareness and surroundings) and attention while awake.
what are the three reticular formation descending tracts
reticulospinal
ceruleospinal
raphespinal
what is the reticulospinal
posture and gross limb movements
what is the ceruleospinal
from the locus coeruleus. autonomic, physiologic responses to stress and panic, and alertness. Inhibits pain and nocioception
what is the raphespinal
from raphe nuclei,
sensory, autonomic and motor. cardiovascular system, and inhibits pain signals.
coma
un-arousable, no response to strong stimuli
stupor
arousable only by a strong pinch
obtunded
spelling more then awake
vegetative state
complete loss consciousness, spontaneous eye opening, regular sleep wake cycles, normal respiratory patterns.
minimally conscious state
following minimally simple commands, gestures to yes/no, intelligible speech,
syncope
brief loss consciousness because of drop in BP
delirium
reduced attention, orientation and perception. also agitation
what is the Glasgow Coma Scale
eyes, are they already open, do you need a strong stimulus, soft, are they not opening.
verbal, can give name place and date, or not oriented or no words, just sounds, or none.
motor: can they move on command, is it normal or abnormal
what are the red flags for brainstem dysfunction
dysphagia (swallowing, 5,7,9,10,12)
dysarthria (speaking, CN 5,7,10,12)
diplopia (double vision)
dysmetria (impaired control of movement, like missing a target)
where are the pyramids on the medulla? whats laterally
anterior, and just lateral are the olives
where does CN 12 exit
between the pyramids and olives
where do CN 9 + 10 exit
lateral to the olives
which side of the medulla are the inferior cerebellar peduncles
the posterior side
the central canal is continuous with the SC and in the upper medulla widens and becomes the
4th ventricle
what cranial nerve nuclei are in the medulla
7,8,9,10,12
what cranial nerves make up the solitary nucleus
7,9,10: visceral afferents, and taste
what CN make up the nucleus ambiguous
motor fibers to the striated muscles in the phkyaryn, larynx and upper esophagus, so CN 9 + 10
what do the lateral corticospinal tracts do in the medulla
their axons decussate
where do the Doral columns decussate
medial lemniscus of the medulla
TF: the spinothalamic tracts run through the medulla
true
the spinocerebellar tracts get to the cerebellum via the
inferior cerebellar peduncle
what are the functions of the medulla
- eye and head movements and postural control (vestibular nuclei- CN 8)
- swallowing (nuclei ambiguous- CN9,10)
- cardio and respiratory (dorsal motor vagus, CN10)
- visceral activity/taste (solitary nucleus, 7,9,19)
what CN come from the pons
the trigeminal (5)- face sensation
abducens (6)- lateral eye movement
facial (7)- facial muscles and chewing
vestibulocochlear (8)- head and neck and ear
the anterior portion of the pons contains the
- descending tracts (corticospinal, corticobrainstem and corticopontine),
- pontine nuclei
- pontocerebellar axons.
the posterior portion of the pons is called the
tegmentum
what does the tegmentum of the pons contain
the sensory tracts,
- reticular formation,
- autonomic tracts and
- CN nuclei (5-8)
how does the pons communicate with the cerebellum
the cerebellar peduncles
what are the functions of the pons
face sensation (CN 5) expressions and taste (7) chewing (7 and 5) lateral eye movement (6) hearing, head position and neck position (8)
what is another name for the midbrain
the mesencephalon
the midbrain connects what two things
the diencephalon, and the pons
what structure passes through the midbrain
the cerebral aqueduct, which connects the 3rd and 4th ventricle
there are three parts of the midbrain, what are they from anterior to posterior
basal pedunculi
tegmentum
tectum
the basal pedunculi is the anterior portion of the midbrain. what is on this surface
- the cerebral peduncles (descending tracts from the cerebral cortex)
- substantia nigra (part of the BG)
the tegmentum houses what tracts
the vertical sensory tracts
there are lots of important things in the tegmentum… name them
- superior cerebellar peduncle (midbrain to the cerebellum, efferent info)
- red nucleus (from the cerebellum/cortex to the cerebellum or SC. rubrospinal tract and the reticular formation)
- PPN: regulates muscle tone, part of BG)
- CN 3 and 4 nuclei:
- periaqueductal gray
in the tegmentum, what does the oculomotor nuclei do
efferent to the extra-occular muscles, and PNS control of pupillary contraction and the ciliary muscle.
what does the trochlear nuclei do
superior oblique
what is the function of the periaqueductal gray
around the cerebral aqueduct, this coordinates somatic and ANS responses to pain, threats and emotions
starts the fight or flight, laughing and crying.
what is the tectum
the posterior midbrain
what is in the tectum
the pretectal area (reflexes of the eye)
and the colliculi (superior and inferior )
what does the inferior colliculi do
relays auditory information from the cochlear nuclei to the superior colliculi and the medial geniculate body
what does the superior colliculi do
orientation and sensory and motor and reflex, orients the eyes and head to external stimuli and movements.
the vertebral artery branches from the
subclavian
where does the vertebral artery enter the skull
the foramen Magnum
the vertebral arteries join to form the ___ at the base of the ____
basilar,
pons
the basilar artery will divide at the junction of the ___ and ___ to become the _____
pons and midbrain
posterior cerebral artery
the posterior cerebral artery supplies the ____
inferior and middle portions of the posterior cerebellum
the basilar artery has two branches…
the superior cerebellar and the anterior inferior cerebellar
the superior cerebellar supplies the
the superior 1/2 cerebellum and some midbrain
the anterior inferior cerebellar artery supplies
the anterior and inferior cerebellum (at junction of pons and medulla)
the posterior inferior cerebellar artery is off what artery? and supplies what
the vertebral, supplies the post and inf part of the cerebellum
disruption of the posterior inferior cerebellar artery causes
lateral medullary syndrome.
disorders of the brainstem include CN’s and tracts as well. how would each present
CN ipsilateral
tracts: contralateral
when there is ischemia in the brainstem, what are some rapid symptoms
dizzy, visual disorders, weak, incoordination and somatosensation disruption
what happens when there is vertebrobasilar artery insufficiency
transient symptoms, (especially with head and neck extended and rotated)
the cerebellum is also known as the
little brain
there are __x as many neurons in the cerebellum, compared to the cortex
4
the cerebellum integrates information from the __ lobe, and compares it to actual movement
planned movement from the frontal lobe, with actual movements.
what are the functions of the cerebellum
compares actual motor output with intended movement, and coordinates and refines activity.
movement rhythm, timing and synchronization
is the cerebellum conscious or non conscious
non
are there direct connections between the cerebellum and motor neurons
no
if there are no connections, how can it influence movement.
it is connected to motor tract cell bodies int he motor, premotor cortex and the brainstem,
what happens if there is damage to the cerebellum
impaired coordination, postural control and decreases in emotional dan cognitive function
cerebellum controls/regulates ___ movements
ipsilateral
what is the cerebellum anatomy, outer and inner
outer is grey matter with output purjunkie fibers. inner is white.
where is the cerebellum in the head
in the posterior cranial fossa, posterior to the brainstem and inferior to the occipital lobe
what separates the cerebellum and the occipital lobe
the tentorium cerebelli (dura)
what are the three lobes of the cerebellum
the anterior posterior and flocculonodular.
what is the inferior part of the posterior lobe, and what is damage to this called
the tonsils, and damage here is when they herniate in the foramen Magnum, this is called the Arnold chari malformation, and it compromises breathing, cardio and the 4th ventricle.
each hemisphere of the cerebellum is attached to the brainstem by 3…
peduncles
what does the superior peduncle do
cerebellar output and efferents to the midbrain, then to the cortex and red nucleus
what does the middle peduncle do
input to the cortex by the pons, afferent
what does the inferior peduncle do
input from brainstem and SC, output to vestibular and reticular nuclei
what is the rule of 3s with the cerebellum
there are 3 of everything, hemispheres/lobes, regions, layers, arteries, peduncles.
what 3 branches give blood to the cerebellum
the superior cerebellar
the anterior inferior
the posterior inferior
what portions of the cerebellum are supplied by the superior cerebellar
superior cerebellum and a little bit of the pons (rostral lateral dorsal)
what portions of the cerebellum are supplied by the anterior inferior cerebellar
lateral caudal pons, and small part cerebellum
what portions of the cerebellum are supplied by the posterior inferior cerebellar
supplies the lateral medulla and inferior cerebellum
an infarct in which artery will cause unilateral hearing loss. why?
AICA, because it gives rise to the internal auditory artery
where are infarcts more common
the SCA and PICA
what can infarcts cause
swelling, brainstem compression
what is the patient presentation in someone with a cerebral artery infarct
vertigo, nausea, dizzy, nystagmus, limb ataxia, unsteady gait, HA.
what are the three functional regions of the cerebellum
the vestibulocerebellum, spinocerebellum, and cerebrocerebellum
the vestibulocerebellum is part of what lobe
flocculonodule
what is the purpose of the vestibulocerebellum
regulate equilibrium, coordination, postural control and eye and head movement.
what happens with damage to the vestibulocerebellum
unsteady while reaching for a book, trunk ataxia, and nystagmus
what regions make up the spinocerebellum
the vermis and paravermal region
what does the spinocerebellum portion of the cerebellum do
connects with the SC and coordinated gross limb movements.
what does injury to the spinocerebellum look like
jerky and inaccurate movement, tremor, ataxic gait, dysarthria, dysdiadochokinesia, dysmetria, and movement decomposition.
what regions make up the cerebrocerebellum
the lateral hemispheres.
what does the cerebrocerebellum in the cerebellum do
coordinates precise, distal voluntary movement. movement planning and timing
what happens with damage to the cerebrocerebellum
finger ataxia, dysarthria, and cannot correct movements, as they are going wrong.
the cerebellum is contra or ipsilateral movement
ipsilateral
what are some of the roles of the BG
goal directed behavior, social and emotional and motor control
where is the BG located
deep within the white matter of the cerebral hemispheres.
how does the BG control movement
it predicts the effects of an action, and makes and executes a motor plan.
TF: the BG is vital for normal motor function, sequencing of movements, and cognitive functions
true
what are the main components of he BG
the caudate nucleus, the putamen, globus pallidus, sub thalamic nucleus, and substantial nigra.
where is the substantia nigra located
the midbrain (basal pedunculi), dorsal to the cerebral peduncles
the caudate nucleus has a
head, body and tail
the putamen is what
a large nucleus, forming the lateral parts of the BG
what connects the caudate and the putamen
the striatum, which are cellular bridges.
where is the globus pallidus
just medial to the putamen “pale globe”
the globus pallidus and putamen together are known as the
lenticular nucleus
what is the ventral and dorsal portions of the substantia nigra called
ventral: substantia nigra pars reticulata
dorsal: substantia nigra pars compacta
the substantia nigra plays a big role in
parkinsons
inputs to the basal ganglia arrive via the
striatum (caudate nucleus, and the putamen.)
what NT/NM is associated with inputs to the BG
glutamate, from the cortical motor areas, this excites the striatum
outputs exit vie the
internal segment of the globus pallidus and the substantia nigra pars compacta.
the substantia nigra pars compacta (dorsal part) send neurons to where and cause the release of what
striatum (caudate nucleus and putamen) and release dopamine.
the release of dopamine from the striatum does what to the output signals,
it adjusts them, and inhibits target nuclei.
the globus pallidus internus inhibits
motor thalamus, pedunculopontine nucleus and midbrain locomotor region.
what does the basal ganglia motor circuit output regulate
muscle contraction, force, multi-joint movements, and sequencing.
does the BG have direct output to LMN
no
how does the BG get motor outputs out there
motor thalamus, PPN, midbrain locomotion region.
what are the BG loops, and what do they do
they all contribute to full BG functioning. they predict future events, control desired and undesired behaviors and motor leaning, shift attention and spatial working memory
what is the motor loop connection
links the putamen, globus pallidus and VL thalamic nucleus to the motor and premotor cortex.
what is the role of the motor loop
movement selection, action, regulating contraction, force, multi-joint movement and sequencing.
what is the oculomotor loop connections
links the frontal and supplementary eye fields with the caudate body, SN reticular and the VA thalamic nucleus.
what is the role of the oculomotor loop
regulate spatial attention, eye movements, and reactive prosaccades.
what are prosaccades
the eyes moving rapidly, to read a book or watch a train pass by
what is the goal directed loop links
the head of the caudate, globus pallidus and the VA of thalamic nucleus to prefrontal cortex.
what is the role of the goal directed loop
goal directed behavior, perpetual decision making, and plans and decides on actions, in context.
give an example of how the goal directed loop may work
you are running late and the light is turning red. You decide if you have time to run the red light. you also decide which is more important, the interview or going for beers.
what kind of deficits do we see with the goal directed BG loop
inattention, distracted, disoriented, poor concentration and short term memory issues.
what are the links in the social behavior loop
head caudate SN reticular and the mediodorsal thalamic nucleus to the VL prefrontal and lateral orbital cortex.
what is the role of the social behavior loop
recognize social disapproval, self control, discerning relevant and irrelevant information, maintaining attention, and stimulus response learning. if granny, in the passenger seat, does or doesn’t want you to run that red light.
what happens if there is damage to the social behavior loop
violent and sexual behavior, and inappropriate. impulsive, frustrated, violent.
what are the links of the emotional loop of the BG
ventral striatum, ventral pallidum, and MD thalamic nucleus to the medial prefrontal cortex.
the ventral striatum links the ___, ____ and ___ systems
limbic, cognitive and motor
the emotional loop is responsible for what
reward seeking, addition, gambling.
what is the role of the emotional loop
determines the value of a stimulus, reward based behaviors, monitors predicted errors and pleasure seeking.
what are the types of movement disorders of the BG
hypo or hyper kinetic.
the BG inhibits the
motor nucleus, PPN, and the midbrain locomotor region.
if there is excessive inhibition
hypo kinetic,
parkinsons
if there is inadequate inhibition
hyper kinetic. Huntington’s (jerky movements and dementia, and you move in your sleep), dystonia (sustained contraction, abnormal posture and testing, but disappears in sleep. THINK BRENDAN), Tourettes (vocal and tics), dyskinetic CP (abnormal muscle tone and posture and involuntary movement.)
