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 |
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Term
how thick is the cerebral cortex
what makes up for this
what are the layers of the cortex |
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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 |
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|
Term
| what are the two types of cells in the cortex: describe dendrites, shape, and general function |
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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 |
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|
Term
| what are three stains that can be used for the neocortex, what do they tell us about the cells |
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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 |
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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 |
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Term
| what layers of the neocortex have axons that enter the white matter |
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Definition
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|
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 |
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Term
| what are the contents of the external granular layer |
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Definition
| pyramidal neurons and stellate neurons |
|
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Term
| what are the contents of the external pyrmidal layer |
|
Definition
| Association and commissural fibers |
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Term
| what are the inputs to the internal granular layers, what is most prominent in these layers |
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Definition
o Receives thalamocortical connections (especially thalamic nuclei)
o Most prominent sensory cortices |
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Term
| internal granular layer input |
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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) |
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Term
| what are the infragranular layers connected to, what is there main function |
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Definition
o Connect cerebral cortex and subcortical regions
o Most developed motor areas |
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Term
| internal pyrmidal layer: cells, output |
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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 |
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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 |
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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 |
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Term
| how can the brain be seen, what does each type of imaging tell us |
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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 |
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Term
| sensory areas of the brain: name them, connected to, general function, general location |
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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 |
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|
Term
| primary somatosensory cortex: broadmans areas, function, what happens if you stimulate it, what happens if you destory it |
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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) |
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|
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 |
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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 |
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Term
| what is the input and output to the primary somatosensory cortex |
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Definition
• Input: general somatic sensory receptors from the skin. proprioceptors in skeletal muscle, joints, and tendons. all information passes through thalamus
• Output: corticospinal tract |
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Term
| secondary somatosensory cortex: input, output, location |
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Definition
• Location: ventral to primary somatosensory cortex, superior lateral sulcus
• Input: primary somatosensory cortex
• Output: to insula |
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|
Term
| somatosensory association cortex: general location, general input, general function, two main broadmans areas locations |
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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 |
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Term
| broadmans areas 5 and 7: input, what happens if it is destoried |
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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) |
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|
Term
| broadmans area 40: function, what happens if there is a lesion |
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Definition
• Function: higher perception mechanisms for touch machine
• lesion: tactile agnosia: inability to identify an object by touch |
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|
Term
| what syndroms come from the destruction of broadman's area 40: name, deficit, one location |
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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 |
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|
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 |
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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 |
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Term
| primay visual cortex: broadmans area, location, input, what happens if destoried |
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Definition
• Largest cortical sensory area
area 17
• Location: occipital lobe on calcarine sulcus
• Input: lateral geniculate
• Destruction: visual field deficit |
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|
Term
| secondary and tertiary visual cortex: broadmans areas, location, lesion |
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Definition
area 18-19
• Location: surrounds primary visual cortex in concentric bands
• Lesion: visual hallucinations |
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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 |
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Definition
Contralateral homonymous hemianopia, lower quadrantanopia
Gerstmann syndrome |
|
|
Term
| gerstmann syndrome: cause, symptoms |
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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) |
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|
Term
| primary auditory cortex: broadmans area, location, function, input, destruction |
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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 |
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|
Term
| auditory association cortex: broadmans area, functions, partitions and their general functions |
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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 |
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|
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 |
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Definition
• Location: insula posterior to gustatory cortex
• Function: conscious perception of visceral sensation |
|
|
Term
| primary olfactory cortex: location, function, other included areas |
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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 |
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|
Term
| motor cortex: general location, function, decussation patters, damage outocme, parts |
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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 |
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|
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 |
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|
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) |
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|
Term
| premotor cortex functions |
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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%) |
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|
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 |
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|
Term
| supplementary motor cortex: stimulation, ablation, lesion |
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Definition
d. Stimulation: vocalization and facial movements coordinated with limb movemens
e. Ablation: transient speech deficits or aphasias
f. Lesion: hypertonus of flexor muscles |
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|
Term
| frontal eye field: broadmans area, output, stimulation, lesion |
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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 |
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|
Term
| what are the multimodal association areas, what is there input |
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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 |
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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 |
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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 |
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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 |
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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 |
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|
Term
| what happens if you damage brocas area |
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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 |
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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 |
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Definition
Location: under supramarginal gyrus (40) and frontoparietal operculum
Connects audiovisual areas (22, 39, 40) to broca’s speech areas (44-45)
Conduction aphasia |
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Term
|
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 |
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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 |
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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 |
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|
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 |
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|
Term
| what are some functions of the non-dominant hemisphere |
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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 |
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|
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
|
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
|
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
|
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
|
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
|
|
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
|
|
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 |
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Term
| what is the only true input the dentate nuclei recieves, explain the pathway |
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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 |
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Term
| where does the dentate nuclei send information out to |
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Definition
| primary motor cortex, premotor cortex, prefrontal association cortex, posterior parietal association cortex |
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Term
| explain the pathway between the dentate nuclei and premotor and primary motor cortex |
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Definition
| dentate nuclei > majority of fibers leave > ventrolateral nuclei thalamus > parietal lobe motor cortices |
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Term
| explain the path between dentate and association cortices, what are their functions |
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Definition
dentate > middle peduncle >
prefrontal association cortex: working memory, storage for behavioral plans
posterior parietal association cortex: visual perception, attention, motor action |
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Term
| hat are the functions of the cerebrocorticocerebellum |
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Definition
| evaluate sensory info, plan actions, problem solve, decision making, reasoning, language, learning |
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Term
| explain the paths of input of fibers into the vestibulocerebellum |
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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 |
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Term
| explain the pathway of output from the vestibulocerebellum |
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Definition
| fastigal nuclei and vermis > fastigulovestibular > cerebellovestibular > inferior peduncle > vestibular nuclei |
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Term
| because of the input of the cerebellum, what tracts emerge from the vestibular nuclei, what are their functions |
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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 |
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Term
| what are the functions of the vestibulocerebellum |
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Definition
| balance, posture, head and eye movement |
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Term
| what happens if there is a lesion in the vestibulocerebellum |
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Definition
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Term
| explain the paths of input that go to all areas of the cerebellum |
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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 |
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Term
| explain the interaction between the cells of the cerebellum |
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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 |
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Term
| what fibers can excite cerebellar nuclear cells |
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Definition
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Term
| what fibers can inhibit the cerebellar nuclear cells |
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Definition
climbing by exciting purkinje that inhibits
mossy which excites granule which excites purkinje and inhibits |
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Term
| what fibers inhibit granule cells |
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Definition
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Term
| what fibers inhibit purkinje cells |
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Definition
| stellate and basket interneurons |
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Term
| list the layers of the cerebellum begining with the pia mater |
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Definition
pia mater
outer cell body layer
molecular layer
purkinje cell layer
granular layer |
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Term
| functions of the reticular formation |
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Definition
sleep wake cycle
perception of pain
control of movement
regulation of visceral activity |
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Term
| describe the neurons of the reticular formation: organization, function, appearance |
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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 |
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Term
| conciousness: what maintains it, when is it lost, how is it evaluated |
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Definition
entire cortex is used for it
lost in sleep, injury, or disease
impairment is evlauated by testing response to stimuli |
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Term
| in general what are the stages of the sleep wake cycle |
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Definition
steps 1-4: progressivly deeper non-rapid eye movement sleep
5: REM/paraxoxal sleep and dreaming |
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Term
| what parts of the body are active or inactive in REM sleep and why |
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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 |
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Term
| why is the REM sleep paraxoal |
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Definition
| in ways it is deeper and in ways it is more away than stage 4 |
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Term
| what are the two phases of sleep, define them |
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Definition
noctournal: sleep is light and one is easily awakened
deep: need strong sensory stimuli to awaken |
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Term
| what is a EEG, what is it for, how does it work |
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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 |
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Term
| in what situations would someone have a high voltage, low frequency EEG. what does this mean is happening |
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Definition
grops of thalamic neurons fire sinchronously
in sleep stages 3 and 4 and comatose |
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Term
| in what situations would someone have a low voltage, high frequency EEG. what does this mean is happening |
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Definition
cortical neuron is responding to different thalamic afferents
fully alert awake person, showing desynchronization, seen in REM sleep |
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Term
| what does a flat EEG mean |
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Definition
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Term
| what are some pathways involved in sleep that dont stimulate the entire cortex |
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Definition
neurons of the diencephalon and telencephalon
some neurons in the brainstem and hypothalamus promote sleep
hypothalamus tuberomamillary nuclei |
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Term
| what does the hypothalamus tuberomamillary nuclei have to do with sleep, how does this help in medicine |
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Definition
secretes histamine into thalamus and cortex
antihistamine sedatitives block H1 receptors on cortical neurons |
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Term
| what is unique about the fibers that stimulate the entire cortex in sleep cycle |
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Definition
| they are anatomically separate from the other sensory systems of the cerebellum and basal ganglia |
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Term
| what are the three pathways that stimulate the entire cerebral cortex in sleep, where do they all come from |
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Definition
they come from the reticular formation
noradrenergic neurons
cholinergic neurons
central tegmental tract |
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Term
| noradrenergic neurons: functions, MOA |
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Definition
excite cortex
locus ceruleus cells: more active when awake, less active in REM |
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Term
| cholinergic neurons: where do they come from and go to |
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Definition
come from pedunculopontine nuclei
go to hypothalamus, basal cholinergic nuclei of the forebrain, and intralaminar thalamic nuclei |
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Term
| what is the role of the basal cholinergic nuclei of the forebrain in sleep |
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Definition
| stimulate neurons throughout the cortex |
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Term
| what is the role of the intralaminar thalamic nuclei in sleep |
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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 |
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Term
| where is the central tegmental tract |
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Definition
| in center of reticular nuclei (especially oral pontine part) |
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Term
| where does the central tegmental tract project to |
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Definition
| intralaminar thalamic nuclei, basal cholinergic nuclei of the forebrain |
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Term
| what is the function of the centra tegmental tract |
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Definition
| mixed neurons that are active in all states of conciousness and sleep |
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Term
| what is the result of a bilateral lesion in the intralaminar nuclei |
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Definition
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Term
| what can cause in irreversible coma |
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Definition
| bilateral destruction of medial brainstem at or above the upper pons |
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Term
| why is there conciousness in a medial coma lesion |
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Definition
| lateral ascending paths are not interrupted by medial coma lesion which saves pontine reticular formation and conciousness |
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Term
| what are the nuclei that function in sleep |
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Definition
serotonergic raphe neurons
lateral hypothalamus
suprachiasmatic nucleus
cholinergic neurons of pedunculopontine nuclei and lateral dorsal trigeminal nuclei
ventrolateral preoptic area |
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Term
| serotonergic raphe nucleus: functions |
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Definition
active in sleep via serotnin in thalamus and cortex
less active in REM: reduction of inhibition |
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Term
| what may account for REM eye movements |
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Definition
| reduction in inhibition in REM via serotonergic raphe nuclei and other inhibition reductions in pontine nuclei |
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Term
| lateral hypothalamus: function and MOA in sleep |
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Definition
produce orexin A and B active in wake state
stimulate cholinergic neurons of pedunculopontine nuclei |
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Term
| narcolepsy: cause, symptoms |
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Definition
deficiency of orexin from lateral hypothalamus due to gliosis (scaring) of neurons because of degeneration or autoimmune disease
fall into REM sleep randomly |
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Term
| suprachiasmatic nucleus: location, function |
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Definition
in hypothalamus acting every 24 hours
axons contact orexin neurons of lateral hypothalamus and dorsomedial hypothalamic nuclei which project to locus ceruleus |
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Term
| what do cholinergic neurons of the pedunculopontine nuclei and lateral dorsal trigeminal nuclei do |
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Definition
| activated in REM and wake state |
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Term
| where is the ventrolateral preoptic area |
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Definition
|
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Term
| what does the ventrolateral preoptic area fo |
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Definition
GABAnergic neurons with glanin
inhibitor actions in deep nonREM sleep
inhibit tuberomamillary nuclei, locus cerleus, and cholinergic reticular nuclei |
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Term
| what happens in a lesion of the ventrolateral preoptic area |
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Definition
insomia
shows its an essential region for sleep |
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Term
| what areas are active in REM sleep |
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Definition
| cholinergic neurons of pedunculopontine nuclei and lateral dorsal trigeminal nuclei, |
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Term
| what areas are resting or inactive in REM sleep |
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Definition
| noradrenergic (locus ceruleus), intralaminar thalamic nuclei, serotonergic raphe neurons, lateral hypothalamus (orexin prevents REM), |
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