MBB 1 Flashcards
mnemonic for short acting local anesthetics
Poor Ester, she was deCLARED too SHORT to be an ARTIST
Procaine (converted to paba)
Chloroprocaine (v short duration)
articaine (v rapid onset)
why do some people experience phantom limb pain?
because the brain has redistributed the cortical region that used to belong to the amputated limb to other parts of the body
the mind still perceives that the limb is present, so stimulation of the body part that has cortex from the phantom limb will also cause sensation on area where limb used to be
What part of the body has no nociceptors?
BRAIN
what are the 3 types of nociceptors; which is most common?
- polymodal mechanoheat receptors (respond to extreme pressure and temp and allergens) –> MOST COMMON
- mechanonociceptors (alpha delta fibers, pin prick pain)
- silent nociceptors (inflammation)
what protein is necessary for differentiation of ventral spinal cord
sonic hedgehog (SHH)
how does deep brain stimulation work?
- tries to prevent haphazard firing of subthalamus
- stimulation tries to decrease stimulation of subthalamus or globus pallidus internal to weaken indirect pathway (allows for some compensatory movement)
what separates the temporal lobe from the frontal and parietal lobes
lateral fissure (sylvian fissure)
emotional processing requires both _______ input and ______ processing
peripheral
central
what will happen to the generator potential if you stimulate a nerve ending at two places?
what term describes this
- IT WILL INCREASE
spatial summation
what happens if you lose olfactory neurons?
you can make more via basal cells! (decreases as you get older)
in weber’s syndrome, what is affected
- occulomotor nucleus, corticospinal and corticobulbar tract –> contralateral body paralysis, contralateral lower facial paralysis, contralateral tongue, ipsilateral oculomotor paralysis (dilated pupil, down and out, droopy eyelid)
name three conditions associated with inhibitory interneuron dysfunction in the cortex
- epilepsy, overexcitation of inhibitory interneurons
- hyperacusis, auditory system has lost control of excitation and inhibition,, any soudn is associated with painful stimuli
- schizophrenia- malformation of inhibitory interneurons
if you lose your vertical gaze center what happen
if you lose your paramedian pontine reticular formation what happens
if you lose your frontal eye frields what happens?
if you lose your superior colliculus, what happens
if you lose a portion of place code, what happens
- can’t do verticle saccades
- can’t do horizontal saccades
- can do saccades, but will take longer and will be off
- can do saccades, but will take longer and will be off
there is redundancy between left frontal eye fields and supercolliclus
you will have a blindspot/blind sight that corresponds to that location in space (can still do imagined targets, but not fixed targets )
what role does the pag and it’s downward structures play in sensation?
- can provide analgesia via stimulation (opioids at any of these levels can do this)
- stimulates raphe nuclei (which is serotonergic) which goes down and stimulates dorsal horn to relieve pain
what separates the alar and basal plates
sulcus limitans
name the three components of a local anesthetic and what they are important for
lipophilic- potency, duration of action
ester/amide- metabolism, hypersensitivity
hydrophilic- mechanism of action, onset of action
what is wallenberg’s/lateral medullary syndrome?
can be due to occlusion of pica as it goes around medulla
will affect spinocerebellar tract –> ataxia
spinal trigeminal ganglion –> ipsilateral facial pain and temp loss
lateral spinothalamic tract –> contralateral body loss of pain and temp
what are the five biogenic amines
- dopamine, norepinephrine, epinephrine, serotonin, histamine
for the parasympathetic nervous system:
what are the length of pre and post ganglionic neurons
what does each ganglion release
where do the nerves for this system originate
what does this system regulate
What parts of the body have no parasympathetic innvervation
- pre are long and post are short
- pre and post release acetylcholine
- brain stem (cranial nerve 3,7,9,10) and sacral spine (S2-4)
- rest and digest (slows heart, mucus glands, digestion, urination)
- arms, leg, blood vessels of head and neck, adrenals
after a stroke, some patients get severe spontaneous pain to certain areas of the body
describe why and what the term for this is
what can you do to treat it
- damage to somatosensory tracts that deliver pain –> leads to cortico pain neurons going wild
- thalamic pain or central pain syndrome
- mirror visual feedback for repetitive transcranial magnetic stimulation
describe the anterolateral pathway of bring general visceral afferents back to the spine/brainstem
- general visceral afferents go via splanchnic or spinal nerve back through dorsal root ganglion, decussate, and then go up dorsal column to nucleus solitarius OR synapse on interneurons/motor neurons for reflex
what local anesthetic should you use if yo u are intolerant to epinephrine? why?
mepivacaine, has the least vasodilating effect
what parts of the ear are affected in sensorineural hearing loss?
inner ear and beyond!
what condition is optic neuritis classically associated with?
multiple sclerosis
failure of the anterior neural pore to close causes what?
failure of the posterior neural pore to close causes what?
what can prevent majority of neural tube defects during pregnancy
anencephaly
spina bifida
folic acid
what parts of the brain does the posterior cerebral artery innervate
inferior temporal lobe and occipital lobe
describe the pathway for micturation and include the three types of nerves present
sympathetic (L1-3), sensory from hypogastric, keeps bladder relaxed and internal sphincter closed
parasympathetic (S2-4), sensory from pelvic nerves, contracts bladder and relaxes internal spincter
somatic (S2-4) sensory and motor from pudendal nerve, tonically contracts external sphincter until instruction from pons
- bladder distension is senses and goes up to pons which coordinates parasympathetic activation, sympathetic inhibition, and inhbition of the pudendal nerve/external sphinctor
what are the two types of neurons involved in the corticospinal and corticobulbar tracts
layer V pyramidal neurons
betz cells
for what kind of stroke is tpA indicated
in what window can you administer tpa
ischemic stroke (contraindicated for hemorrhagic stroke)
less than 3 hours from onset of symptoms
what are the three chambers of the cochlea? what fluid are they filled with?
MTV used to be famous on a grand SCALE
scala media (endolymph) scala tympani (perilymph) scala vestibule (perilymph)
What is the medial geniculate nucleus involved in?
what is its input from
where is its output
what does a lesion here cause?
- audition
- inferior colliculus
- primary auditory complex
- no deficit since projections are bilateral, deficits only if lesion is bilateral
what is the difference between pyramidal smile and extrapyramidal/duchenne smiling?
where do they converge?
pyramidal- voluntary smiling (motor cortex)
extapyramidal/duchenne- involuntary smiling (hypothalamus)
reticular formation
the strength of long term potentiation or depression is dependent on the time between presynapse activity and post synapse activity; what is this phenomenon called?
if the presynaptic activity precedes the post synaptic activity, what will this result in?
if the post synaptic activity precedes the pre synaptic activity, what will this result in?
- spike-timing dependent plasticity
- long term potentiation
- long term depression
what is a transient ischemic attack (TIA)
what is it strongly associated with
what are clinical manifestations?
- a <5 min episode of ischemia that resolves itself
- atherosclerosis (aka high indicator that another attack or stroke will occur)
- left arm numbness, monoocular blindness, facial numbness, language disturbance, dizziness
what is syringomyelia?
what deficits would you expect
- condition of ballooning of the central canal in the spinal cord (usually due to chiari malformation)
- destruction of ventral white commissure –> bilateral loss of pain and temp
the ____ (more,less) myelinated and the ______ (larger/smaller) the diameter of a neuron, the higher the susceptibility of a local anesthetic to cause a block
give an example of a neuron like this
less myelinated
smaller diameter
pain neuron
the _______ is the weakest amount of stimulus necessary that can be detected 50% of the time
absolute threshold
describe activity dependent/experience dependent learning in the context of long term potentiation and long term depression
- increased use of certain synapses and decreased use of synapses allows the brain to adapt over time
long term potentiation- synaptic strength increases when presynaptic and post synaptic neuron fire simultaneously (neurons that fire together wire together)
long term depression- synaptic strength decreases when presynaptic and post synaptic neurons fire asynchronously (neurons that fire out of sync lose their link)
what is encoding failure
what is retrieval failure
- when your ability to consolidate is disrupted, aka by substance abuse or trauma
- the memory is stored but you can’t retrieve it
how much of glucose is used for aerobic respiration, glycogen synthesis, amino acid synthesis, and nadph synthesis
85% aerobic respiration
5% amino acid synthesis
5% glycogen synthesis
5% nadph synthesis
describe energy consumption from the prenatal period until adulthood
- prenatal more anaerobic (glycolysis) than aerobic (little oxygen used)
- birth to 6 months- less dependence on glucose and more dependence on ketones from fatty breast milk
- after 6 months and throughout childhood, will use aerobic respiration af (50% of body consumption of o2 between 4-9)
- o2 consumption decreases to 20% in adulthood
which semi circular canal resides on which axis and give an example of a motion that would activate the canal
- horizontal canal –> z axis, saying no
- anteriorcanal —> y axis, saying yes
- posterior canal –> x axis, cartwheel
name the 4 things that neural crest cells differentiate into?
MANS melanocytes autonomic ganglia neurosecretory cells sensory ganglia
what are the three types of ionotropic glutamate receptors; what functions are they involved with?
does glutamate bind to metabotropic receptors?
which receptor may require a co-agonist? name the co-agonist
AMPA: everywhere, used in most excitatory synapses
NMDA: used in learning, memory, synaptic plasticity
Kainate: not well understood
yes!! 3 classes (don’t need to know specifics)
NMDA receptor- glycine
where on the spinal cord do upper motor neuron axons from the motor cortex go? what does this mean about what lower motor neurons they regulate?
where on the spinal cord do upper motor neuron axons from the brain stem go? what does this mean about what lower motor neurons they regulate?
- lateral white matter, regulate lower motor neurons that affect distal structures/fine touch
- medial white matter, regulate posture and balance
what artery supplies the putamen, caudate and internal capsule?
what does it branch off of
lenticulostriate artery
middle cerebral artery
depression has been associated with increased blood flow to which region of the brain?
what can decrease the blood flow?
pre frontal cortex
anti-depressants, ssri
what is the difference between a noncommunicating hydrocephalus and a communicating hydrocephalus?
non-communicating- due to obstruction of csf flow, so csf accumulates through anterior fontanelle
communicating- issue with reabsorption from arachnoid granulations
what is tabes dorsalis
what deficits would you have
- demyelination of afferent fibers bilaterally in dorsal column
- will have bilateral loss of fine touch/proprioception
where in the thalamus do body somatosensory neurons synapse?
what about head somatosensory neurons?
what brodmann’s areas do they project do?
VPL
VPM
Brodmann’s 3,1,2
what is the medial longitudinal fasciculus?
what is it involved in
the tract of nerves from the abducens nucleus to the occulomotor nucleus
- voluntary gaze/ medial rectus contraction
what is a specific receptor that modulates synaptic plasticity of thalamic cortical nuclei?
does this process happen all the time?
- nmda receptor (glutamate)
- only during critical period
what would happen to your memory if you lose your hippocampus? what types of memory are unaffected
- can’t consolidate declarative long term memory
- working memory and long term nondeclarative memory
the cavernous sinus and superior sagittal sinus drain into the ______
transverse sinus
what are two ways to convey the intensity of a stimulus
- increase the number or frequency of action potentials (NOT THE SIZE THOUGH)
- increase the number of sensory receptors involved/recruited (ex: a small stimulus only stimulates one receptor but a strong stimulus stimulates/recruits multiple sensory receptors)
what is bitemporal hemianopsia?
what can cause it? what is a sudden severe version of this called?
- loss of temporal visual field bilaterally
- anything that compresses optic chiasm, usually pituitary tumor
- if sudden growth of tumor or hemorraging of tumor –> pituitary apoplexy
What is the pulvinar involved in?
what is its input from
where is its output
what does a lesion here cause?
- higher order visual processing
- super and inferior colliculi, lateral and medial geniculate nuclei
- attentiona/neglect deficit syndromes
the lower the pK, the _____ (slower,faster) the onset of a drug. why?
faster
more of molecules is in unionized/uncharged form, so it can diffuse faster
what size motor unit is better for fine touch/detail?
what size motor unit is better if you need to generate significant force?
what motor unit has the lowest threshold for innervation? what about highest threshold?
- small
- large
- small
- large
what role does the nose play in taste?
- large role, odorants from food go up behind palate and into nose, if you have cold or loss of olfaction, food doesn’t taste as good
If a patient had right abducen nerve palsy, what would happen if you asked the patient to look to the right? what would if you asked them to look to the left?
- if they looked to the right, the left eye would function normally and move to the right but the right eye would not move (esotropia)
- if they looked to the left, both eyes would function normally and look to the left
what cortex is in the post-central gyrus
somatosensory cortex
in medial pontine syndrome, what is affected
- abducens nucleus and corticospinal tract –> ipsilateral lateral rectus paralysis and contralateral body deficits
what is the limbic system composed off
what is its function?
- components of telecenphalon, diencephalon, and mesencephalon,
aka fornix, cingulate gyrus, amygdala, nucleus accumbands, hypothalamus, mammillary body, hippocampus
- MLEM Please motivation learning emotion memory pleasure
how do dry and wet age related macular degeneration differ?
which form can be halted or reversed, with what
dry: slow progressive bilateral loss of central vision (most common)
wet: complication of dry, oxidative damage to choroid vessels leads to increases vegf and neovascularization that hemorrhages (CAN BE REVERSED OR HALTED, WITH INTRAOCULAR ANTI VEGF))
what protein is necessary for differentiation of the dorsal spinal cord and hind brain
bone morphogenic protein (BMP)
what protein is necessary for differentiation of neural crest cells and cerebellar granule cells
Wnt
describe the stretch/deep tendon reflex
- monosynaptic
- feel extension stretch (ex: filling drink) –> 1a and II afferents activated and synapse on alpha motor neurons to flex the same muscle
- -> send excitatory synapse to synergistic muscle to help
- -> send inhibitory synapse to antagonist muscles
what is the place code in reference to vision?
for the vestibuloocular reflex, how do you convert place code into rate code?
- the fact that every point along an x y axis of your vision has a specific place in the brain that encodes it
- the faster your head moves, the faster and more frequency action potentials are sent to the placecode, which is hard wired to the eom
What is the ventral lateral region involved in?
what is its input from
where is its output
what does a lesion here cause?
- modulation of coordinated movement
- cerebellum
- primary motor cotex
- akinesia (loss of voluntary movement)
describe the nerve fibers in the pathway for the baroreceptor reflex
- blood pressure increases, which the carotid body sinus detects via stretch; glosopharyngeal afferents are sent and go through petrosal ganglion and synapse in nucleus solitarius, then motor afferents via vagus go through nucleus ambiguous and to heart to decrease hr and relexively sympathetic is inhibited
what condition is drusen associated with
age related macular degeneration
what area of the brain is associated with comprehension of language?
in what lobe is this area?
wernicke’s area
temporal lobe (think, its in the same lobe as hearing)
what are the two main functions of the pons
what are other functions
- regulation of breathing (pneumotaxic center) and signal transmission within the brain (ie to or from cerebellum or cerebrum)
- balance, hearing, taste, deep sleep
what lab value will be elevated during pregnancy if a neural tube defect is present?
what two sources can you measure this lab value from?
- alpha feto protein
- maternal serum or amniotic fluid
describe symptoms of lower motor neuron syndrome
paresis or paralysis hypotonia hyporeflexia atrophy fibrillations or fasciculation flaccidity
describe the pathway from the putamen being activated to the cerebral cortex (direct pathway)
1) need significant input from multiple inputs to surpass significant threshold in putamen spiny neurons
2) release GABA, which inhibits the globus pallidus internus
3) this disinhibits GABA release from the gp internus to the thalamus
4) now the thalamus can send signal to specific places in the cortex to activate specific motor neurons
what is the miller law of 7?
max you can remember is 7 units +/- 2
if you want visceral pain to reach consciousness in the brain, what pathway do you take?
describe the pathway
dorsal column pathway
-enter the dorsal horn and synapse at midline, then travel up the dorsal column (with medial lemniscus) and eventually reach VP of thalamus which then synapses on the cortex
which two sections of the spinal cord are enlarged and why?
- cervical (C3-T1) for increased nerve cells and connections to process information from the arms
- lumbosacral (L1-S2) for increased nerve cells and connections to process information from the legs
in additon to v and t snares fusing, what is a necessary protein that links vesicle release to ca influx?
synaptotagmin
what is the mid brain composed of?
what does it do?
- tectum (posterior)
- cerebral peduncles (tectum and crus cerebri)
- VHS TAMpering vision hearing sleep/wake temperature regulation arousal motor control
give examples of crude touch modalities
in general are the axons big and myelenated or small and unmyelenated
pain
coarse touch
temperature
- small and unmyelenated
what are optokinetic movements
how does this differ from vestibulo-ocular movements
- you are in an object that is moving and you are stabilize your gaze on an object passing by, and then your eye is capable of shifting and stabilizing on the next object (optokinetic nystagmus)
- this is movement of the eyes that will stabilize the gaze when your head is bobbing/moving (will move in the opposite direction of your head) (vestibulokinetic nystagus)
what is a main difference between bupivicaine and ropivicaine? (2 things)
bupivicaine is significantly more cardiotoxic and can be used post-joint replacement surgeries
what is the main difference between nonproliferative and proliferative diabetic retinopathy?
- proliferative has neovascularizations/angiogenesis
in medial medullary syndrome, what is affected
- hypoglossal nerve and cortico spinal tract –> contralateral body deficits and ipsilateral tongue deviation
parkinson’s disease is due to neurodegeneration of what?
what symptoms do you get a result and why
what medication can help treat and why
substantia nigra pars compacta
bradykinesia (slow movement), rigidity and stooped posture, resting tremor (hypokinetic tremor)
- due to the fact that now you need higher threshold for activation direct pathway and lower threshold for activating indirect pathway
L-dopa- dopamine precursor, will create more dopamine to make remaining dopamine pathways stronger
what is the difference between anterograde and retrograde amnesia
anterograde- can’t form new memories
retrograde- can’t retrieve old memories
what are the three types of GABA receptors
GABA A- everywhere ,implicated in many drugs (benzos, Alcohol, steroids, Anesthetics
GABA B- metaBotropic
GABA C- in the eye (C is for SEEing)
which anesthetic type is metabolized in the liver?
- amides
what neuron is responsible for regulating the synapse between ganglion neurons and bipolar cells
amacrine cell
describe the pathway of memory input in the hypothalamus
name a clinical scenario that often implicates this pathway
- from the hippocampus via the fornix to the mamillary body to the anterior hypothalamus
- Korsakoff’s from b1 deficiency and drinking –> short term memory loss due to damage to mamillary body
what is proprioception?
what are the size of the axons
- recognizes our self position and movement
- large and myelinated
what is the trace decay theory?
- there is a path to where a memory is stored, and if you don’t rehearse the memory, then the path to that memory wil fade but the memory will still be there
a stimulus causes a(n) _____ potential
if the stimulus is strong enough to reach threshold, it becomes a(n) _____ potential
- receptor/generator
- action
what functions does the medulla do?
- regulation of breathing
- heart and blood vessel function
- digestion
- sneezing
swallowing
what is the most common demographic to get vertigo?
old women
name four cns diseases can affect smell and taste
dementia
parkinsons
multiple sclerosis
schizophrenia
what kind of receptor are hair cell receptors?
mechanoreceptors
what local anesthetic can cause methemoglobinemia?
what can you use to treat it?
- prilocaine
methylene blue
what is the only glial cell in the retina?
what does it do
muller cell
- keeps parallel array of retinal layers and eats dead neurons
what are the two membranes of the cochlea
tectorium and basilar
if you have 3rd nerve palsy, what should the affected eye look like?
- dilated, pointing down and out (only 4th and 6th nerve muscles working, aka superior oblique and lateral rectus), droopy eyelid
What is the VPL and VPM involved in?
what is its input from
where is its output
what does a lesion here cause?
- somatosensation for head (VPM) and body (VPL)
- VPL–> medial lemniscus
- VPM –> ventraltrigeminothalamic tract
lateral spinothalamic tract (lateral funniculus) - somatosensory cortex
- contralateral loss of all somatosensation
in humans, the rostral caudal axis is tilted forward due to the _________ made during embryogenesis
cephalic flexure
what parts of the brain does the middle cerebral artery innervate
frontal lobe, parietal lobe, and temporal bone
where do layer 2 pyramidal neurons go to?
where does layer 3 pyramidal neurons go
where do layer 5 pyramidal neurons go
where do layer 6 neurons go
- go through cortex layers and to other cortices within same hemisphere
- go through cortices to cortices within the same and contralateral cortices
go to subcortical structures like superior colliculi, brainstem, spinal cord
- thalamus
what do hair cells have on their surface to detect vibration?
what connects them to each other?
stereocilia
tip links
what part of the hypothalamus is sexually dimorphic
preoptic area
what do interneurons do within the 6 layers of the cortex?
- inhibitory, turned on my pyramidal neurons, act locally usually within the same layer
What is the anterior nucleus involved in?
what is its input from
where is its output
what does a lesion here cause?
- memory, emotion
- mamillothalamic tract
- cingulate gyrus
- significant memory deficit/amnesia
80% of neurons in the cortex are _____ neurons
what are layer 4 neurons called
pyramidal/principal neurons
- stellate neurons
what is the main neurotransmitter for pain? what does it do
SUBSTANCE P (P FOR PAIN)
- sensitizes nociceptors
- potent vasodilator
- releases 5ht from platelets
- releases histamine from mast cells
what are the two type of muscle spindle receptors? how do they differ?
- Group Ia: rapid adapting, respond to changes in muscle stretch and vibration
- Group II: slow adapting; respond to sustained stretch/limb position
what are the two major sites of action for norepinehprine and what functions does it facilitate
what transports norepi into vesicles
what enzymes break it down
what type of post synaptic receptors does it bind to?
- periphery- sympathetic nervous system
- locus ceruleus- attention and arousal
- vesicular monoamine transporter (VMAT)
- monoamine oxidase and cytosoli catechol o methyltransferase
- metabotropic (alpha and beta )
neurons from the motor cortex ________ at the caudal medullary pyramid to innervate the contralateral side of the body
decussate
what cells provide scaffolding for the nervous system, take up potassium, provide glucose, and can regulate neurotransmitters?
astrocytes
What is the ventral anterior region involved in
what is its input from
where is its output
what does a lesion here cause?
- initiation and planning of movement
- basal ganglia
- premotor cortex
- akinesia (loss of voluntary movement)
there are three divisions to proprioception, describe them and where they project to
- conscious (learning new motor skills/plasticity)- goes to somatosensory cortex
- unconscious (reflex control)- goes to spinal cord
- unconscious (reflexes and motor control)- goes to cerebellum
what process shares a similar mechanism to long term potentiation but actually does the opposite and can reverse long term potentiation?
describe the process
- long term depression
- usually involved in low frequency, constant stimuli
- activates nmda receptors, but instead of secondary cascade of kinases that brings more ampa receptors to the surface, it activates phosphatases that internalize more ampa receptors
name some physical exam findings consistent with nonproliferative diabetic retinopathy
- dot blot hemorrhages, microaneurysms, exudates, macular edema
CSF is made in the ______
describe the flow of CSF
blockage of CSF can lead to _____
- choroid plexus
- lateral ventricles –> interventricular foramen –> third ventricle –> cerebral aqueduct –> 4th ventricle (lushka and magendie) –> taper into central canal
- hydrocephalus
how many nodes of ranvier must a local anesthetic block in order to block the entire axon?
what kind of neuron would this be easier to do?
3 nodes
small unmyelinated neurons
for idiopathic intracranial hypertension:
what demographic is most commonly affected
what is the largest risk factor
name clinical manifestations
- women of childbearing age
- obesity/weight gain
- headache, visual blackout, pulsatile tinnitus, enlarged blindspot
what affect does leptin have in the hypothalamus, and which nuclei have receptors for it?
what would happen if you had a leptin receptor deficiency
- will reduce appetite
anterior, lateral, paravenricular and arcuate nuclei
would gain weight af because your appetite is never supressed
huntington’s disease to do to a ______ repeat and is due to neurodegeneration of ______
what can you use to treat it and what does it do
CAG
striatum to globus pallidus external
haloperidol, dopamine antagonist, will help try to decrease threshold of activation for indirect pathway so it can function more
describe rachischisis
- neural folds fail to fuse (type of spina bifida)
where are the first order neurons of trigeminal afferents present? what is the one exception?
where do the neurons go after?
- trigeminal ganglion (outside of cns)
- proprioception first order neuron cell bodies are in mesencephalic nucleus in midbrain
proprioception neurons –> mesencephalic trigeminal nucleus (midbrain)
fine touch/pressure neurons –> main sensory trigeminal nucleus (pons)
pain and temperature neurons–> spinal trigeminal nucleus (medulla and spine)
what 2 swellings does the prosencephalon eventually form
telencephalon and diencephalon
if the convolutions of your cerebral cortex are very small, what is this called?
what clinical manifestations is this associated with?
microgyria
- mental retardation and physical defects
what separates the frontal lobe from the parietal lobe?
central sulcus
medially situated motor neuron pools in the ventral horn innervate ____ muscles and are involved more in ______
laterally situated motor neuron pools in the ventral horn innervate ____ muscles and are involved more in ______
- proximal/trunk
- balance/posture
- distal limb
- fine motor movement
where do lower motor neurons originate?
where do they synapse?
- brainstem (cranial nerve nuclei)
- spinal cord (ventral horn)
- directly on skeletal muscle
what artery supplies the occipital lobe?
if stroke occurs in this artery, why do some patients manage to maintain central vision?
- posterior cerebral artery
- small portion of middle cerebral artery supplies portion of occipital lobe responsible for central vision, so some blood supply is maintained in a posterior cerebral artery stroke
if you want to test and superior rectus and inferior rectus, where should the patient look
- out and then up and down
describe the process by which glutamate is made and recycled
1) glutamine is brought into the presynaptic terminal via System A 2 Transporter (SAT2)
2) glutamine is converted into glutamate and transported into vesicles via Vesicular Glutamate Transporters (VGLUTs)
3) once glutamate is released into the synaptic cleft, it is either taken up by the post synaptic neuron or is taken up by astrocytes via Excitatory Amino Acid Transportors (EAATs)
4) glutamate is converted by into glutamine via glutamine synthetase
5) glutamine leaves the System N transporter 1 (SN1) and the process starts all over
anencephaly is due to what?
what is missing?
is this compatible with life?
failure of the anterior neural pore to close
some or all of the cerebral hemispheres
nah
describe the process of how ischemia leads to neuronal cell death
- ischemia –> decreased o2 use and increased lactic acid
- ion pumps fail –> k released into ecm and neurons get depolarized
- neurons release glutamate vesicles, which activate nmda receptors –> ca influx –> cell apoptosis triggered
what is kluver bucy syndrome
what is another disease that is similar and describe what is affected
- damage to amygdala, have sexually inapprorpiate behavior, loss of fear and anger, emotional flattening, hypermetamorphosis, oral tendency (explore things with mouth), can’t recognize faces
urbache- wiethe disease: bilateral calcification and atrophy of anterior temporal lobes, can’t recognize fear or anger
why is the cornea clear but the sclera is white
what is one function they both do?
both are made of collagen fibers, but cornea’s collagen fibers are very organized whereas sclera’s are disorganized, which causes it to be white
PROTECTION
what part of the brain contextualizes your emotion input and response based on what is socially appropriate
pre frontal cortex
describe the process in which vesicles are recycled after releasing NT
1) clathrin coats membrane and allows for significant invagination
2) dynamin pinches membrane off to form coated vesicle
3) auxillin and hsc 70 remove clathrin coating, making it ready to accept NT again
what is the major excitatory neurotransmitter in the cns; what kind of receptor is it; what is the reversal potential?
what is the major inhibitory neurotransmitter in the cns? what kind of receptor is it; what is the reversal potential
- glutamate; non-selective cation ionotropic receptor; reversal at 0 mV
- GABA; chloride ionotropic receptor, reversal at -70 mV
what are the three main symptoms of horner’s syndrome
name 5 causes
Is it a sympathetic or parasympathetic nervous system problem
miosis, anhydrosis( not sweating), and ptosis
apical lung tumor, dissected carotid body, tumor in cavernous sinus, stroke
sympathetic! (lose it)
what area of the brain is associated with the motor component of speech?
in what lobe is this area?
broca’s area
frontal lobe (think, it’s in the same area as motor cortex)
if a patient has right eye internuclear opthalmoplegia, what would happen if you asked the patient to look to the right? what would if you asked them to look to the left?
- if they looked to the right, right and left eye would function normally and move to the right
- if they looked to the left, left eye would move to left, but would be pulsating (nystagmus) and the right eye would not move (exotropia)
