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Neuro Block 8
KYCOM Block 8
162
Anatomy
Graduate
05/04/2013

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Cards

Term
what is a gyri
what is a sulcus
what type of neurons are in the cortex
what is a comissure
what are the comissures of the cortex
Definition
• Gyri: elevations
• Sulci: grooves or fissures
• All neurons are interneurons

Commissures
o Nerve fibers that connect the cerebral hemispheres to coordinate function
Corpus callosum: largest, Anterior commissure, Posterior commissure, Hippocampal commissure
Term
how thick is the cerebral cortex
what makes up for this
what are the layers of the cortex
Definition
o 2-4 mm thick, convolutions triple surface area
o Superificial cortex gray matter
o Internal white matter
o Basal ganglia nuclei: islands of gray in the white matter
Term
what are the two types of cells in the cortex: describe dendrites, shape, and general function
Definition
Stellate cells
 Spheroidal bodies
 Short dendrites
 Receive sensory and process it locally
Pyramidal cells
 Tall, conical, apex toward brain
 Dendrites have many branches and dendritic spines
 Dendrites pass into white matter for cerebral output
Term
what are three stains that can be used for the neocortex, what do they tell us about the cells
Definition
o Golgi stain shows neuronal bodies and dendritic trees
o Nissil stain shows cell bodies and proximal dendrites
o Weigert stain shows myelinated fibers and thus axons
Term
what are the layers and sublayers of the neocortex
Definition
supragranular layers
1. molecular
2. external granular
3. external pyrmidal

internal granular layer
4. internal granular

infragranular layers
5. internal pyrmidal
6. multiform/fusiform
Term
what layers of the neocortex have axons that enter the white matter
Definition
3, 5, 6
Term
where is the molecular located, what are its contents
Definition
 Superficial below pia mater
 Contents: dendritic tufts of pyramidal neurons, horizontal axons, glial cells, cajal, rezius, spiny stellate cells
Term
what are the contents of the external granular layer
Definition
pyramidal neurons and stellate neurons
Term
what are the contents of the external pyrmidal layer
Definition
 Association and commissural fibers
Term
what are the inputs to the internal granular layers, what is most prominent in these layers
Definition
o Receives thalamocortical connections (especially thalamic nuclei)
o Most prominent sensory cortices
Term
internal granular layer input
Definition
 Receives thalamocortical fibers from thalamic nuclei of the ventral tier (VPL, VPM)
 Striate cortex (17) receives input from the lateral geniculate
 Myelinated fibers form stripe of gennari (visible to eye)
Term
what are the infragranular layers connected to, what is there main function
Definition
o Connect cerebral cortex and subcortical regions
o Most developed motor areas
Term
internal pyrmidal layer: cells, output
Definition
 Output of corticobulbar, corticospinal, and corticostriatal fibers
 Contains cells of Betz in motor cortex (4) precentral gyrus and anterior paracentral lobule
 Fibers go to basal ganglia, brainstem, and spinal cord
Term
multiform / fusiform layer: output, location
Definition
 Output of projection, commissural, and association fibers
 Output of corticothalamic fibers (majority)
 deepest
Term
what are the layers of the allocortex / geterogenetic cortex: what are their functions, locations, and layers
Definition
archiocortex
o Hippocampus and dentate gyrus
o 3 layers
o memory
paleocortex
o Olfactory cortex of temporal lobe and insula
o 1-5 layers
Term
what are brodmans areas based on
Definition
o Based on neuron density, cortex thickness, and cell types
o A particular anatomical structure corresponds to a particular function
o Motor and sensory functions are localized in specific cortex areas
Term
how can the brain be seen, what does each type of imaging tell us
Definition
o Positron emission tomography (PET): show metabolic activity
o Functional MRI: show blood flow
o Polysomnogram: measures brain and body activity during sleep
o Single photon emission computer tomography (APECT): slows blood flow to tissue and evaluates brain function
Term
sensory areas of the brain: name them, connected to, general function, general location
Definition
• Connected to the thalamus and basal ganglia
• Conscious awareness of sensation
• In parietal, insular, temporal, and occipital lobes

primary sensory, secondary somatosensory, somatosensory association, primary visual, secondary and tertiary visual, visual association, primar auditory, auditory association, gustatory, vestibular, visceral sensory, primary olfactory
Term
primary somatosensory cortex: broadmans areas, function, what happens if you stimulate it, what happens if you destory it
Definition
broadmans areas 1-3
• Location: Postcentral gyrus, posterior paracentral lobule
• Function: Spatial discrimination: identify body region stimulated
• Stimulation: tingling and numbness contralateral
• Destruction: loss of tactile discrimination contralateral (hypesthesia and astereognosis)
Term
explain how the primary somatosensory cortex is organized: what is the name of this organization, how is the body represented, ratios, locations of fibers, decussation locations
Definition
 sensory homonuclus, somatotopical
 body is represented spatially and upside down
 face, lips, and fingers take up most space and are more sensitive
 face and hands are closer to the lateral sulcus
 fibers decussate before gyri
Term
what is the input and output to the primary somatosensory cortex
Definition
• Input: general somatic sensory receptors from the skin. proprioceptors in skeletal muscle, joints, and tendons. all information passes through thalamus
• Output: corticospinal tract
Term
secondary somatosensory cortex: input, output, location
Definition
• Location: ventral to primary somatosensory cortex, superior lateral sulcus
• Input: primary somatosensory cortex
• Output: to insula
Term
somatosensory association cortex: general location, general input, general function, two main broadmans areas locations
Definition
 Posterior to primary somatosensory cortex in parietal lobe
 Input from areas 1-3 and 7
 Function: integrate tactile and visual stimuli to conceptualize, shape, form and evoke memory

superior parietal lobule: 5 and 7
supramarginal gyris: 40
Term
broadmans areas 5 and 7: input, what happens if it is destoried
Definition
• Area 7 also receives input from area 17
• Destruction: contralateral loss of tactile discrimination, sterognosis, statognosis (position of body in space), neglect syndrome (more common on right side)
Term
broadmans area 40: function, what happens if there is a lesion
Definition
• Function: higher perception mechanisms for touch machine
• lesion: tactile agnosia: inability to identify an object by touch
Term
what syndroms come from the destruction of broadman's area 40: name, deficit, one location
Definition
o Ideomotor or classic apraxia. Inability to button ones clothes, use tools, retention to explain their use
o Ideational or sensory apraxia. Cant formulate plan for executing complex act. More frequent in cerebral degeneration (Alzheimers)
o Facial apraxia: Cant perform facial oral movements on command. Most common
o Conduction aphasia: Poor repetition of speech. Interruption of the arcuate fasiculus
Term
what is the visual pathway, what happens if there is a lesion in the optic nerve, what happens if there is a lesion in tract radiation or cortex
Definition
 Retina > lateral geniculate of thalamus > occipital cortex
 Lesion of optic nerve produces total blindness in ipsilateral eye
 Lesion of optic tract, optic radiations, or optic cortex make contralateral homonymous field defects
Term
primay visual cortex: broadmans area, location, input, what happens if destoried
Definition
• Largest cortical sensory area
area 17
• Location: occipital lobe on calcarine sulcus
• Input: lateral geniculate
• Destruction: visual field deficit
Term
secondary and tertiary visual cortex: broadmans areas, location, lesion
Definition
area 18-19
• Location: surrounds primary visual cortex in concentric bands
• Lesion: visual hallucinations
Term
visual association cortex: broadmans area, location, input, function
Definition
area 39
• Location: angular gyrus
• Input: areas 18-19
• Function: dots are formed into lines and lines are recognized as shapes
Term
what happens if you destory area 39
Definition
Contralateral homonymous hemianopia, lower quadrantanopia
Gerstmann syndrome
Term
gerstmann syndrome: cause, symptoms
Definition
• Destruction in dominant hemisphere
• Right/left confusion
• finger agnosia (cant recognize fingers or name),
• agraphia (can’t express thoughts in writing
• dyscalculia (difficulty with math)
Term
primary auditory cortex: broadmans area, location, function, input, destruction
Definition
area 41-42
• Location: transverse gyri of heschl at temporal lateral fissure at caudal superior temporal gyrus
• Function: auditory processing, interpretation of language in dominant hemisphere
• Input: medial geniculate
• destruction partial deafness due to bilateral cochlear sensation
Term
auditory association cortex: broadmans area, functions, partitions and their general functions
Definition
area 22
• location: posterior superior temporal gyri
• functions: perception of sound, memory of sound
 Wernicke speech area: language comprehension
 Plantum temporale: part of wernckes that is larger in dominant hemisphere
Term
lesion in area 22: diseases, their location, general symptoms
Definition
 Wernicke sensory aphasia: In dominant hemisphere. Sensory aphasia: cannot understand what they hear
 Sensory dysprosody:In non-dominant hemisphere. Cant perceive pitch or rhythm of speech
Term
gustatory cortex: broadmans area, location, input
Definition
area 43
• Location: parietal operculum and parainsular cortex
• Input: taste from VPM
Term
vestibular cortex; broadmans area,location, input
Definition
area 2
• Location: postcentral gyrus (posterior insula and parietal cortex)
• Input: VPI, VPL
Term
visceral sensory area: location function
Definition
• Location: insula posterior to gustatory cortex
• Function: conscious perception of visceral sensation
Term
primary olfactory cortex: location, function, other included areas
Definition
• Location: medial temporal lobe in piriform lobule by uncus
• Function: conscious awareness of odors
• Rhiencephalon includes oribofrontal cortex, uncus and medial temporal lobe, olfactory tracts, olfactory bulbs
Term
motor cortex: general location, function, decussation patters, damage outocme, parts
Definition
• Control voluntary movement
• In posterior frontal lobe
• All contralateral
• Damage: contralateral upper motor neuron (UMN) paralysis

primary motor cortex, premotor cortex, supplementary motor cortex, frontal eye field
Term
primary motor cortex: location, output, cells in it, stimulation, ablation, lesion
Definition
area 4
a. Location: precentral gyrus, anterior paracentral lobule
b. Output: corticospinal/pyramidal tract
d. In layer 5 has cells of Betz
e. Stimulation: contralateral movement of voluntary muscles
f. Ablation: contralateral upper motor neuron lesion
g. Lesion: paracentral lobule lesion causes urinary incontinence
Term
explain the organization of the primary motor cortex: name of it, how it is orientated, ratio for the body
Definition
i. motor homonuculus, somatotopical
ii. body is represented upside down: head at inferolateral precentral gyrus and toes at superomedial end
iii. most neurons are for face, tongue, and hands
Term
premotor cortex: broadmans area, location, output, stimulation, lesion
Definition
area 6
a. Location: anterior to precentral gyrus in frontal lobule
b. Output: corticospinal tract
d. Stimulation: adverse movements of the head and trunk in flexion and extension
e. Lesion: in dominant hemisphere causes sympathetic apraxia (motor apraxia in left hand)
Term
premotor cortex functions
Definition
i. control of proximal and axial muscles. BRS
ii. Control of learned motor skill repetitions or patterns machine
iii. Coordinate movement of muscle groups mostly by sending impulses to the primary motor cortex (only direct supplies 15%)
Term
supplementary motor cortex: broadmans area, location, output, function
Definition
area 6
a. Location: anterior to paracentral lobule
b. Output: corticospinal tract
c. Function: programming complex motor sequences, coordinating bilateral movements, regulate somatosensory input to motor cortex
Term
supplementary motor cortex: stimulation, ablation, lesion
Definition
d. Stimulation: vocalization and facial movements coordinated with limb movemens
e. Ablation: transient speech deficits or aphasias
f. Lesion: hypertonus of flexor muscles
Term
frontal eye field: broadmans area, output, stimulation, lesion
Definition
a. Location: posterior middle frontal gyrus
b. Output: corticotectobulbar (machini says corticobulbar) to contralateral gaze center of pons abducens nuclei
c. Stimulation: conjugative deviation of eyes to opposite side
d. Lesion: conjugate deviation of eyes to side of lesion
Term
what are the multimodal association areas, what is there input
Definition
• Input from many unimodal association areas and output to many areas

Posterior association area, anterior association area, limbic association area
Term
posterior association area: location, function, major broadmans areas it includes
Definition
o Location: temporal, parietal, and occipital lobe
o Function: recognize patterns of faces, localize individuals and surroundings
o Includes Wernicke speech area: area 22
Term
anterior association area: location, function, development
Definition
o Location: frontal lobe prefrontal cortex
o Function: intellect, complex learning, recall, personality, working memory, abstract ideas, judgment, reasoning, persistence, planning
o Development: slowing in kids, depends on positive and negative feedback
Term
limbic association area: location, function
Definition
o Location: cingulate gyrus, parahippocampal gyrus, hippocampus
o Function: emotional impact, importance of things, memories
Term
what are the three main areas of the brain having to do with language and their broadmanns numbers, how is it decided what side of the brain does language
Definition
Right handed people are left side dominant and left side has language. Left handed people often use right side for language

Broca’s speech area: are 44-45
Wernicke speech area: area 22
arcuate fasiculus
Term
brochas speech area: location, function
Definition
Location: posterior inferior frontal gyrus in dominant hemisphere

Connected to Wernicke speech area via arcuate fasiculus

Function: coordinate muscles used in speech
Term
what happens if you damage brocas area
Definition
inability to say what is thought (motor or non-fluent aphasia)
• Good comprehension
• Effortful telegraphic non-fluent speech
• Poor repetition
• Contralateral lower facial and upper limb weakness
Term
brocas aphasia: cause, AKA, symptoms, awareness?
Definition
• Lesion on Broca speech area
• AKA: motor, expressive, non-fluent, anterior aphasia
• Speak slow with effort, good comprehension, contralateral weakness of lower face and arm, sympathetic apraxia of left hand
• Patient knows what they want to say and cannot express themselves
Term
wernicke speech area: location
Definition
Location: posterior superior temporal gyrus in dominant hemisphere

Connected to broca speech area via arcuate fasiculus
Term
wernicke aphasia:AKA, cause, symptoms, associated diseases
Definition
• AKA sensory, receptive, fluent, or posterior aphasia
• Lesion in dominant hemisphere
• Poor comprehension of speech, speak fast, can’t find the right word, unaware of deficit, fluent, poor repetition,
• Associated with quadrantopia (vision deficit)
• Normal grammar and style with word substitution
Term
arcuate fasiculus: location, what does it connect, what disease is associated with thi
Definition
Location: under supramarginal gyrus (40) and frontoparietal operculum

Connects audiovisual areas (22, 39, 40) to broca’s speech areas (44-45)

Conduction aphasia
Term
what is lateralization
Definition
some higher functions are specific to a certian hemisphere
Term
what are some functions of the left brain
Definition
• Experience: Usability / analytic (analytical, logic, language, science and math)
• verbal, calculating, analytical thinking
• interpretation of speech, stereognosis, motor function of right hand
Term
what are symptoms of a lesion in the left brain
Definition
• paralysis of right side, possible loss of speech, agnosias, and aphasias
Term
what are functions of the right brain
Definition
• Experience: Design / creativity (holistic thought, intuition, creativity, art, music)
• Nonverbal, spatial, temporal, synthetic function
• Appreciation of art and music
• Motor function of left hand
Term
what are symptoms of a lesion in the right brain
Definition
• Loss of visual spatial awareness, paralysis of left side (often with neglect)
Term
how can you test for sure dominant hemisphere: name of test, how it is done, why you would do it
Definition
Wade Test
o Identifies dominance before surgery to avoid damaging speech
o Intracarotid sodium amobarbital procedure (ISAP) Injected into carotid. If person becomes aphasic anesthetic was administered into dominate hemisphere. Works by acting on GABA-A receptors
Term
how does the dominant hemisphere develop, what are someg general functions
Definition
oDevelopment: As a newborn either could be dominant, one slowly dominates. At 10 years it is fixed
o Functions: Propositional language: grammar, syntax, semantics. Speech and calculation
Term
what are some functions of the non-dominant hemisphere
Definition
three demetoional perception, speech and calculation
Term
expressive dysprosody: cause, symptoms
Definition
lesion in brocas speech area in non-dominant hemisphere

Cannot inflect emotion or inflection in speech

Dysprosody: emotion of speech, inflection, melody, emphasis, gesturing
Term
receptive dysprosody: cause, symptoms
Definition
lesion of wernickes speech area in the non-dominant hemisphere

cant comprehend emotion and inflection
Term
corpus callosum: job, contents, blood supply
Definition
1. Interconnects corresponding hemispheric areas
2. No commissural fibers from the hand
3. Blood supply: anterior cerebral, posteror cerebral, splenium
Term
split brain syndrome: cause
Definition
o Transection (comissurotomy) of corpus callosum (Treatment for severe epilepsy)
o Hemispheres cannot communicate
Term
split brain syndrome: symptoms
Definition
o Tactile and visual perception projected to contralateral hemisphere
o Olfaction is perceived on the same side
o Audition is perceived on the opposite side
o Left hemisphere is dominant for language
o Right hemisphere is dominate for spatial construction and non-verbal ideation
o Instability blindfolded to match objects between each hand
o Anomia: Cant name objects when blindfolded
o Cant match object in right half of visual field to left
o Alexia: in left visual field. Verbal symbols in right visual cortex have no access to language in the language centers of the left hemisphere
Term
functions of the cerebellum
Definition
• Subconscious
• Posture and balance, muscle tone
• Regulation of voluntary motor pathways
o calculates best way to perform a movement
o Input into limb, trunk, and eye movement
o Correct for differences between intent and action
• Cognative function
o Language and problem solving
o Predicts sequence of events
o plans movement (parietal and limbic association cortex)
• Receives information from sensory, limbic, and visual systems
Term
superior peduncle: AKA, afferent fibers, efferent fibers
Definition
“brachium conjunctivum”
o Afferent: Ventral spinocerebellar, Trigeminocerebellar, Cerileocerebellar
o Efferent:Fastigovestibular, Fastigothalamic, Interposteriorthalamic, Dentarubrothalamic
Term
middle peduncle: AKA, afferent, efferent
Definition
“brachium pontis
o Afferent: Pontocerebellar
Term
inferior peduncule: two parts, the fibers in each
Definition
o restiform body: Dorsal spinocerebellar, Cuneocerebellar, Olivocerebellar
o “juxta restiform body”: Vestibulocerebellar, Cerebellovestibular
Term
nuclei of the cerebellum
Definition
dentate, interposed (emboliform, globose), fastigal
Term
creutz feldt jacobs syndrome: cause
Definition
o spatiral patterns of vaculoation “spongiform change” in granule, basket, stellate, and golgi cells
Term
lesion in the cerebellum general pattern
Definition
usually affects same side of body
Term
friedreich's ataxia: causes
Definition
o FXN gene mutation autosomal recessive
o Sensory nerve and spinal cord demyelination: Corticospinal tract, Spinocerebellar tract, Fassiculus and cuneates gracilus, Dentate nuclei
o Common in myocarditis patients
Term
friedreich's ataxia: symptoms, treatment
Definition
o Symptoms: Weakness of arms and legs, Loss of coordination, Vision and hearing loss, Slurred speech, Scoliosis, plantar arches
o Treatment: Surgical intervention
Term
ramzey hunt syndrome / dyssynergia: cause, symptoms
Definition
o Autosomal recessive

o Dysarthria: slurred speech
o Dystaxia
o Dysmetria: inability to execute voluntary movement
o Intention tremor: type of dysmetria in voluntary movement
o Dysdiadochokinesia: can’t perform rapid alternating movements
o Nystagmus
o Rebound or lack of check
Term
what is rebound or lack of check, how is it tested
Definition
Cant adjust to changes in muscle tension

Loss of cerebellar component of stretch reflex

Test: patient flexes forearm at elbow against resistance. Sudden release results in forearm striking chest
Term
what is hypotonia
Definition
Loss of resistance during passive range of motion

Due to loss of cerebellar facilitation of motor cortex via tonic firing of cerebellar nuclei

Floppy, loose joints, rag doll appearance, pendular reflexes, looks drunk
Term
what is dyssynergia
Definition
loss of coordinated muscle activity
Term
anterior vermis syndrome cause and symptoms
Definition
o Atrophy of vermis
o Cause: alcohol abuse acting on GABA receptors on cerebellar neurons of leg region of anterior lobe
o Symptoms; gait, trunk, and leg dystaxia
Term
posterior vermis syndrome cause and symptoms
Definition
Cause: brain tumor in children (medulloblastoma or ependyoma) in flocondular lobe

Dystaxia: fall forward or backward. Cant hold head up and steady. Difficult to hold trunk up.
Term
hemispheric syndrome: cause, symptoms
Definition
o Brain tumor or abcess in one cerebral hemisphere
o Symptoms: Arm, leg, and trunk dystaxia, Swaying and falling to side of lesion, Delay in initiating movements, Uncoordinated movement (one joint at a time), Dysarthria and nystagmus, Ipsilateral
Term
phenytoin
Definition
antiepileptic drug causes ataxic, nystagmus, gait disturbance, dysarthric speech
Term
what are the types of cerebellar cancer
Definition
medylloblastoma, astrocytoma, ependymoma
Term
medylloblastoma: location, prognosis, most common patients, cause of symptoms
Definition
vermis granular layer of cortex

Common in kids

Very malignant

Obstruct CSF causing hydrocephalus

Usually subsides by itself
Term
astrocytoma: most common patient, location, prognosis
Definition
Most common brain tumor in kids

Affect cerebellar hemisphere

Prognosis good after resection
Term
ependymoma: location, causes
Definition
Affect upper spinal cord close to 4th ventricle

Causes hydeoencephalus
Term
mossy fibers: come from, go to, function, pathway
Definition
Come from brainstem and spinal cord nuclei

Go to network of excitatory and inhibitory interneurons that synapse on purkinke fibers which project to the cortex

Regulatory to the purkinje inhibitory neurons

Afferent, excitatory, from spinocerebellar and pontocerebellar

Terminate on granule cells exciting them

Inferior cerebellar peduncle
Term
climbing fibers: come from, go to, type of fibers
Definition
Come from inferior olivary nuclei > olivocerebellar tract

Synapse on purkinke fibers (inhibitory neurons)

Send output to the cortex deep nuclei (similar connections as the vestibular nuclei)

Afferent ectivatory
Term
how are the input fibers of the cerebellum (mossy, climbing) inhibited
Definition
purkinje at level of deep neurons
Term
what are the lobes of the cerebellum
Definition
anteriorn, posterior, floccondular, vermis, nodule of vermis, flocculi
Term
what separates the cerebelum from the brain, what divides the hemispheres of the cerebellum
Definition
tentorum cerebelli

cerebrllar incisura on the inferior side only
Term
what are the phlyogenetic divisions of the cerebellum: give their location
Definition
spinocerebellum / paleocerebellum: vermis and enterior anterior lobe

cerebrecerebellum: posterior anterior lobe, posterior lobe

vestibulocerebellum / archicerebellum: floccondular lobe, nodule of vermis, flocculi
Term
what is the name of the white matter of the cerebellum
Definition
arbor vitae
Term
what are the fissures of the cerebellum, what do they divide
Definition
primary fissure: anterior and posterior lobe

posterolateral fissure: separates floccondular and posterior lobes
Term
what are the "gyri" of the cerebellum called, what are they made of
Definition
folia, gray matter
Term
explain the pathway of the fibers that ineract with the interposed nuclei
Definition
intermediate zone of the spinal cord > interposed nuclei > interposedrubrothalamic tract > decussation in midbrain >magnocellular red nuclei > ventrolateral nuclei > frontal motor cortex > lateral descending tracts
Term
what are the lateral descending tracts, what are their functions
Definition
rubrospinal, corticospinak

posture, move trunk and limbs, muscle tone
Term
explain the pathway of the fibers that interact with the interpolar / oral nuclei
Definition
proproceptive information from the spinal cord > trigeminal nuclei > trigeminocerebellar tract > interpolar / oral nuclei
Term
explain the path of the fibers that interact with the fastigal nuclei
Definition
dorsal spinocerebellar and cuneocerebellar tracts > vermis and fastigal nuclei (ones from vermis go to fastigal)> reticular formation and premotor cortex > medial descending tracts
Term
what are the medial descending tracts, where did they come from
Definition
reticulospinal: came from reticular formation via fastigal input.

vestibulo(cortical)spinal: came from pre-motor cortex via fastigal input on fastigulothalamic
Term
what is the function of the dorsal spinocerebellar and cuneocerebellar tracts
Definition
proprioception, stretch reeptors, viscerosensory, somatosensory, audio, visual
Term
explain the dentate nuclei loop
Definition
inferior olivary nuclei > climbing fibers on olivocerebellar tract in inferior peduncle > dentate nuclei > dentoribrothelamic tract > decussation in superior peduncal > paravocellular red nuclei > central trigeminal tract > inferior olivary nuclei
Term
what is the only true input the dentate nuclei recieves, explain the pathway
Definition
motor sensory association neocortex in parietal lobe information on voluntary contraction > corticopontocerebellar (ispilateral)> pontine nuclei > ponto cerebellar tract in middle peduncle > purkinje fiber > dentate nuclei
Term
where does the dentate nuclei send information out to
Definition
primary motor cortex, premotor cortex, prefrontal association cortex, posterior parietal association cortex
Term
explain the pathway between the dentate nuclei and premotor and primary motor cortex
Definition
dentate nuclei > majority of fibers leave > ventrolateral nuclei thalamus > parietal lobe motor cortices
Term
explain the path between dentate and association cortices, what are their functions
Definition
dentate > middle peduncle >

prefrontal association cortex: working memory, storage for behavioral plans

posterior parietal association cortex: visual perception, attention, motor action
Term
hat are the functions of the cerebrocorticocerebellum
Definition
evaluate sensory info, plan actions, problem solve, decision making, reasoning, language, learning
Term
explain the paths of input of fibers into the vestibulocerebellum
Definition
1. vestibular afferents from semicircular canals > vestibulocerebellar tract > inferior peduncle

2. secondary vestibular afferents from vestibular nuclei > vestibulocerebellar tract > inferior peduncle

3. visual cortex > corticopontocerebellar > pontine nuclei > middle peduncle
Term
explain the pathway of output from the vestibulocerebellum
Definition
fastigal nuclei and vermis > fastigulovestibular > cerebellovestibular > inferior peduncle > vestibular nuclei
Term
because of the input of the cerebellum, what tracts emerge from the vestibular nuclei, what are their functions
Definition
1. all nuclei > MLF: eye control vs head movement

2. medial vestibular nuclei > medial vestibulospinal: neck and eye movement

3. lateral vestibular nuclei > lateral vestibulospinal > balance
Term
what are the functions of the vestibulocerebellum
Definition
balance, posture, head and eye movement
Term
what happens if there is a lesion in the vestibulocerebellum
Definition
balance and gait issues
Term
explain the paths of input that go to all areas of the cerebellum
Definition
1. motor cortex sensory input from limbs and trunk > corticospinal > lateral reticular nuclei > mossy fibers > superior peduncle > correction for movement error

2. accessory cuneate in medulla somatosensory from upper trunk and limbs to control movements > inferior peduncle

3. intermediate zone laminae VII C8-L2 > dorsospinocerebellar > inferior peduncle

4. intermediate zone laminae VII C8-L2 > ventral spinocerebellar > decussation in suprior peduncle
Term
explain the interaction between the cells of the cerebellum
Definition
mossy fibers enter cerebellum and excite granule cells and cerebellar nuclear cells in the granular layer

granule cells have fibers that go through the purkinge cell layer and to the top of the molecular layer and bifurcate at 90 deg each way. they send out excitatory signals via glutamate

purkinge cells have dendrites in the molecular layer with aborations that come in contact with a granule cell dendrite and become excited

excitement travels down, through cell body (in the purkinje layer) to their axon (in the granular layer) and synapses on a cereellar nuclear cell inhibiting it. some excitement also goes out of the cerebellum to the vestibular nuclei, inhibiting them VIA GABA

add this into the story. climbing fibers from the inferior olive anter the cerebellum and travel through the granular layer where they can excite cerebellar nuclear cells or travel all the way to the molecular layer and wrap around the dendrits of the purkinje cell and excite them which leads to additional purkinje inhibition of cerebellar nuclear cells and vestibular nuclei

golgi interneurons can stop granular cells from working

stellate and basket interneurons can stop purkinje cells from working
Term
what fibers can excite cerebellar nuclear cells
Definition
climbing and mossy
Term
what fibers can inhibit the cerebellar nuclear cells
Definition
climbing by exciting purkinje that inhibits

mossy which excites granule which excites purkinje and inhibits
Term
what fibers inhibit granule cells
Definition
golgi interneurons
Term
what fibers inhibit purkinje cells
Definition
stellate and basket interneurons
Term
list the layers of the cerebellum begining with the pia mater
Definition
pia mater
outer cell body layer
molecular layer
purkinje cell layer
granular layer
Term
functions of the reticular formation
Definition
sleep wake cycle
perception of pain
control of movement
regulation of visceral activity
Term
describe the neurons of the reticular formation: organization, function, appearance
Definition
net like, reticular, apperance

aggregatins are non-clear nuclei

long dendrites so they can get input from most of the axons in the brain stem
Term
conciousness: what maintains it, when is it lost, how is it evaluated
Definition
entire cortex is used for it

lost in sleep, injury, or disease

impairment is evlauated by testing response to stimuli
Term
in general what are the stages of the sleep wake cycle
Definition
steps 1-4: progressivly deeper non-rapid eye movement sleep
5: REM/paraxoxal sleep and dreaming
Term
what parts of the body are active or inactive in REM sleep and why
Definition
muscles of trunk and limbs are relaxed becuase motor neurons of the spinal cord are inhibited in reticular formation via glycine

more stimuli is needed for arousal because thalamus transmission to cortex is inhibited via GABA (easier than stages 3-4 though)

cerebral cortex active
Term
why is the REM sleep paraxoal
Definition
in ways it is deeper and in ways it is more away than stage 4
Term
what are the two phases of sleep, define them
Definition
noctournal: sleep is light and one is easily awakened

deep: need strong sensory stimuli to awaken
Term
what is a EEG, what is it for, how does it work
Definition
electroencephalogram
indicator of cerebral cortex activity

flux in voltage is the sum of variation in dendritic membrane potential of afferent neurons that came from the thalamus in the cortex
Term
in what situations would someone have a high voltage, low frequency EEG. what does this mean is happening
Definition
grops of thalamic neurons fire sinchronously

in sleep stages 3 and 4 and comatose
Term
in what situations would someone have a low voltage, high frequency EEG. what does this mean is happening
Definition
cortical neuron is responding to different thalamic afferents

fully alert awake person, showing desynchronization, seen in REM sleep
Term
what does a flat EEG mean
Definition
cerebral cortex death
Term
what are some pathways involved in sleep that dont stimulate the entire cortex
Definition
neurons of the diencephalon and telencephalon

some neurons in the brainstem and hypothalamus promote sleep

hypothalamus tuberomamillary nuclei
Term
what does the hypothalamus tuberomamillary nuclei have to do with sleep, how does this help in medicine
Definition
secretes histamine into thalamus and cortex

antihistamine sedatitives block H1 receptors on cortical neurons
Term
what is unique about the fibers that stimulate the entire cortex in sleep cycle
Definition
they are anatomically separate from the other sensory systems of the cerebellum and basal ganglia
Term
what are the three pathways that stimulate the entire cerebral cortex in sleep, where do they all come from
Definition
they come from the reticular formation

noradrenergic neurons
cholinergic neurons
central tegmental tract
Term
noradrenergic neurons: functions, MOA
Definition
excite cortex
locus ceruleus cells: more active when awake, less active in REM
Term
cholinergic neurons: where do they come from and go to
Definition
come from pedunculopontine nuclei

go to hypothalamus, basal cholinergic nuclei of the forebrain, and intralaminar thalamic nuclei
Term
what is the role of the basal cholinergic nuclei of the forebrain in sleep
Definition
stimulate neurons throughout the cortex
Term
what is the role of the intralaminar thalamic nuclei in sleep
Definition
projects to entire cortex
active when awake, resting in REM

recieves contralateral tracts that dont go to entire cortex that are involved in arousal from sleep
Term
where is the central tegmental tract
Definition
in center of reticular nuclei (especially oral pontine part)
Term
where does the central tegmental tract project to
Definition
intralaminar thalamic nuclei, basal cholinergic nuclei of the forebrain
Term
what is the function of the centra tegmental tract
Definition
mixed neurons that are active in all states of conciousness and sleep
Term
what is the result of a bilateral lesion in the intralaminar nuclei
Definition
coma
Term
what can cause in irreversible coma
Definition
bilateral destruction of medial brainstem at or above the upper pons
Term
why is there conciousness in a medial coma lesion
Definition
lateral ascending paths are not interrupted by medial coma lesion which saves pontine reticular formation and conciousness
Term
what are the nuclei that function in sleep
Definition
serotonergic raphe neurons
lateral hypothalamus
suprachiasmatic nucleus
cholinergic neurons of pedunculopontine nuclei and lateral dorsal trigeminal nuclei
ventrolateral preoptic area
Term
serotonergic raphe nucleus: functions
Definition
active in sleep via serotnin in thalamus and cortex
less active in REM: reduction of inhibition
Term
what may account for REM eye movements
Definition
reduction in inhibition in REM via serotonergic raphe nuclei and other inhibition reductions in pontine nuclei
Term
lateral hypothalamus: function and MOA in sleep
Definition
produce orexin A and B active in wake state
stimulate cholinergic neurons of pedunculopontine nuclei
Term
narcolepsy: cause, symptoms
Definition
deficiency of orexin from lateral hypothalamus due to gliosis (scaring) of neurons because of degeneration or autoimmune disease

fall into REM sleep randomly
Term
suprachiasmatic nucleus: location, function
Definition
in hypothalamus acting every 24 hours

axons contact orexin neurons of lateral hypothalamus and dorsomedial hypothalamic nuclei which project to locus ceruleus
Term
what do cholinergic neurons of the pedunculopontine nuclei and lateral dorsal trigeminal nuclei do
Definition
activated in REM and wake state
Term
where is the ventrolateral preoptic area
Definition
anterior to hypothalamus
Term
what does the ventrolateral preoptic area fo
Definition
GABAnergic neurons with glanin

inhibitor actions in deep nonREM sleep
inhibit tuberomamillary nuclei, locus cerleus, and cholinergic reticular nuclei
Term
what happens in a lesion of the ventrolateral preoptic area
Definition
insomia
shows its an essential region for sleep
Term
what areas are active in REM sleep
Definition
cholinergic neurons of pedunculopontine nuclei and lateral dorsal trigeminal nuclei,
Term
what areas are resting or inactive in REM sleep
Definition
noradrenergic (locus ceruleus), intralaminar thalamic nuclei, serotonergic raphe neurons, lateral hypothalamus (orexin prevents REM),
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