Term
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Definition
| Blood vessels and optic nerve. blind spot. |
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Term
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Definition
| yellow color, no large blood vessles, central vision |
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Term
| Refractive power of the cornea |
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Definition
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Term
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Definition
| dimple in the eye that pushes ganlions to the side so light has a direct path to photoreceptors. ONLY CONES |
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Definition
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Anatomy of the Retina Name the Cells and their functions |
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Definition
Photoreceptors to bipolar cells to ganglion cells Ganglion cells - fire action potentials down the optic nerve to the brain Horizontal cells - recieve input from the photoreceptors and projects input laterally to influences surrounding cells Amacrine cells - Recieves input from bipolar cells and projects input laterally... inner plexiform layer - containing the synapses between ganglion cells, amacrine cells, and bipolar cells outer plexiform layer - containing synapses between bipolar cells, horizontal cells, and photoreceptor cells |
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Term
Rod in Darkness Membrane Potential? |
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Definition
MP = -30mv Influx of Na+because cGMP is elevated which causes the sodium channels to be open |
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Term
| Order of activity from light entering the eye |
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Definition
light -> photoreceptors -> stimulation of photopigment -> activate G protein -> activate effector enzyme -> change in concentration of 2nd messanger -> membrane ion channel closes -> Mem. Pot. more (-) THUS IS HYPERPOLARIZED IN LIGHT |
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Term
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Definition
dark = purple light = yellow When activated produces transducin which stimulates the g-protein PDE which breaks down cGMP |
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Term
| What happens to cGMP dark to light rooms |
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Definition
| When in dark Ca2+ enters cones and inhibits the enzyme that destroys cGMP. Light closes channel and enzyme becomes uninhibited. |
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Term
Photoreceptor polarization in light and dark effect on glutamate levels |
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Definition
light = hyperpolarized - > less glutatmate release dark = depolarized - >more glutamate release |
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Term
bipolar cells? Two Classes? Receptive Field? Polarization due to surroundings? |
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Definition
create a direct pathway from the photoreceptors to the ganglion cells Off Bipolar cells - light is off influx of Na2+ depol. On Bipolar cells - Light is on hyperpolarize Receptive Field - stimulated area that causes change in mp Center is where light hits, SURROUND is signals input by the surrounding horizontal cells opposite polarization of center bipolar cell |
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Term
| Ganglion Cell response to light and dark |
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Definition
On - depolarize due to light on center Off - depolarize due dark on center BOTH - when surround is same amount of light then response is greatly reduced Half - Hyperpolarized surround and depolarized center when surround is opposite of center they cancel |
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Term
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Definition
M-type - large 5% of total, low contrast stimuli, rapid ap P-type - small 90% of total sustained discharge nonM-non-P - 5% |
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Term
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Definition
optic nerve -> LGN -(optical radiation)> cotex |
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Term
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Definition
Located: Dorsal Thalamus temporal: 2,3,5 nasal: 1,4,6 1,2 large neurons m-type ganglions 3-6 small neurons p-type ganglions konio layer - nonm-nonp-ganglions color |
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Term
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Definition
top half of cortex = bottom of image bottom of cortex = top of image image is distorted with a focus on the center |
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Term
IVc Neuron Types inside and out, info goes? mLGN & pLGN -> IVc? Konio cells ->? |
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Definition
IVc = spiny Outside = pyramidal -> go to other parts of the brain mLGN -> IVca blobs pLGN -> IVcb blobs b on top of a Konio-> II and III |
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Term
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Definition
blob: color oriented, monocular, no orientation/direction input from konio LGN and p/m of ivc inerblob: binocularity, orientation/direction sensitivty |
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Term
3 parallel pathways to visual cortex what each are for? |
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Definition
M-type pathway (motion): M-ganglion -> m-LGN -> IVca ->IVcB & Blob-> Cortex P-Type pathway (shape): p-ganglion -> p-LGN ->IVCb & blob -> interblob -> cortex Konio pathway (color): nonm/p ganglions ->konio-LGN -> Blobs -> Cortex |
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Term
Nonthalamic Targets of the Optic Tract |
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Definition
– Hypothalamus: Biological rhythms,
including sleep and wakefulness
– Pretectum: Size of the pupil; certain types
of eye movement
– Superior colliculus: Orients the eyes in
response to new stimuli (saccadic eye
movements) |
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Term
| 2 Streams past the Striat cortex |
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Definition
Dorsal stream: Analysis of visual motion and the visual control of action Ventral stream: Perception of the visual world and the recognition of objects |
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Term
Dorsal Stream Area__: Function? |
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Definition
Area MT: Direction-selective; Respond more
to the motion of objects than their shape (temporal Lobe) Area MST: beyond MT resposible for navigation, eye movement, motion perception |
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Term
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Definition
Area V4: orientation & color Achromatopsia:Partial or complete loss of color vision Area IT: after V4, located inferior temporal lobe, facial recognition Prospagnosia: loss of facial recognition |
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Term
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Definition
- sensitive to physical distortions like bending and stretching pacinian corpusle, ruffini's endings, Meisner's corpusle, Merkel's Discs |
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Term
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Definition
- large receptive field, quick short respnse -Stimulus = Vibration |
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Definition
- large receptive field, slow sustained response pressure |
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Term
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Definition
Meisner's corpusle - small receptive field, quick short respnse -deep pressure |
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Term
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Definition
- small receptive field, slow sustained response -sustained touch and pressure |
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Term
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Definition
Group 1 - dia = 13-20um, speed = 80-120m/s info from A axons = proprioceptors of skeletal muscle Group 2 - dia = 6-12um, speed = 35-75m/s info from B axons = Mechanreceptors in the skin Group 3 - dia = 1-5um, speed = 5-30m/s info from D axons = Pain, temperature Group 4 - dia = 0.2-0.5um, speed = 0.5-2m/s info from C axons = Temp, pain, itch |
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Term
| 4 groups of the spinal cord |
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Definition
Cervical Thoracic Lumbar Sacral |
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Term
Dorsal Column-Medial Lemniscal Pathway Pathway for___? |
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Definition
pathway for touch & vibration from B axons B axons -> dorsal column ->dosal column nuclei (spine meets medulla)->left side body=right side brain ->medial lemniscus (synapse) -> Venral Posterior nucleus in the thalamus -> primary somatosensory cortex |
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Term
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Definition
Trigeminal nerve = senses of the face Mechnoreceptors in face->Trigemial Nerve->Trigeminal Nucleus->Thalamus->Sensory Cortex |
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Term
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Definition
Located in the Parietal Lobe 3b -concerned with touch, recieve most info from the thalamus, most responsive to somatory stimulus, lesions impair somatic sensation, stimulation provokes somatic stimulus 3a - body position Area 1 - texture info Area 2 - size and shape |
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Term
| Posterior Parietal Cortex |
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Definition
Visual Stimuli, movement planning, somatic senses Agnosia - inability to recognize objects despite senses being normal Astereognosia - Inability to recognize obejcts through touch despite touch normally Neglect Syndrome - visual fields are neglected |
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Term
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Definition
| Pain receptors, free, branching, nonmyleinated |
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Term
Pain Transmision Hyperalgesia Bradykinin Prostaglandis Substance P |
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Definition
Transmitted through unmyelinated C fibers and lightly myelinated D axons -> dorsal root -> zone of lissauer -> substantia gelatinosa ->brain Hyperalgesia: increased sensitivity to pain Bradykinin: depolarizes, heat sensors more sensitive Prostaglandis: general increase in sensitivy Substance P: Peptide synthesized by nociceptors caused vasodilation and histamine release, increase sensitivty in mechnoreceptors |
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Term
Aferrent Regulation Descending Regulation Opoids |
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Definition
Aferrent Regulation: Reduced pain by activity low-threshold mechanorecptors Descending Regulation: PAG activate raphe nuclei which projects down dorsal and suppress activity Opoids: morphine, blocked by naloxone |
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Term
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Definition
Pain & Temperature Dorsal Root -> Lateral tract -> passed through medulla to synapse in the thalamus -> Cortex |
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Term
Temperature Receptors Trpv 1-4 Trpm8 Anktm1 |
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Definition
Trpv 4,3,1,2 hot sensors in order low -> high temp Anktm 1 & Trpm 8 cold in order low -> high temp |
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Term
axial muscles proximal muscles distal muscles |
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Definition
Axial: Musclie move the trunk Proximal: shoulder, elbow, pelvis, knee Distal: hands, feet, digit |
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Term
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Definition
Alpha: directly trigger generation fo force by muscles -all muscle connected to one alpha are MOTOR UNIT >1 alpha = motor neuron pool |
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Term
| Red vs White Muscle Fibers |
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Definition
Red: sustained contraction w/ lots of mitochondria 30-60 impulses per second White: quick, power few mitochondria 10-20 impulses per second |
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Term
Structure of Muscle Fiber Enclosed by? Message to deep muscle tissue by? Triggers release of __ by ___ into the ____ which causes ____ |
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Definition
Sarcolemma: excitable membrane T tubules continue message deep into fibers Triggers release of Ca2+ by sarcoplasmic reticulum into the myofibrils which causes contraction |
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Term
| Z-lines, sarcomeres, thin filaments, thick filaments, & contraction |
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Definition
Z-lines are brought closer to each other when thin filaments slide along thick filaments, myosin binds with actin. Ca2+ binds with troponin to block myosin/actin rxn |
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Term
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Definition
| When muscle is pulled on it pulls back, controlled by spinal chord |
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Term
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Definition
detects muscle change Alpha motor neuron causes Extrafusal muscles contract (decrease activity in a axons) cause slack inintrafusal muscles, the slack triggers gamma motor neuron trigger reaction to take out slack (increased activity of a axons) |
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Term
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Definition
| strain gauge, output on b axons, sends signal to ventral horn blocks a axons from send contract commands in extreme situations |
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Term
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Definition
| Relaxes antagonist muscles when bending arm |
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Term
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Definition
High - Strategy - Neocortex, basal Middle - tactics - motor cortex, cerebellum Low - Execution - Brain stem, Spinal cord |
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Term
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Definition
Lateral - Voluntary movement under direct cotrical control • Corticospinal tract
• Pyramidal tract
• Rubrospinal tract • Partial lesions in corticospinal and rubrospinal
tracts – Fractionated movement of arms and hands
• Damage of corticospinal tract - Paralysis on contralateral side Ventromedial - posture and locomotion under brain stem control |
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Term
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Definition
Ventromedial - posture and locomotion under brain stem control – The Vestibulospinal tract = balance of head on shoulders – The Tectospinal tract = input from eyes to map world – The Pontine and Medullary Recticulospinal
tract = balance of body pontine=fight grav in balance Medullary= relaxes muscle for balance |
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Term
| Posterior Parietal and Prefrontal Cortex |
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Definition
Movement planning area 6 and area 4 PMA "Ready Set Go" |
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Term
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Definition
| selection and initiation of willed movements |
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Term
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Definition
The Motor Loop: Selection and initiation of
willed movements
– Origin of direct path: Excitatory connection from
the cortex to cells in putamen
– Cortical activation
• Excites putamen neurons
• Inhibits globus pallidus neurons
• Release cells in VLo from inhibition
– Activity in VLo influences activity in SMA |
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Term
Input-Output of M1 What does M1 Code for? |
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Definition
Layer 5 of M1 is begining of motor neuron activation Start in Area 4,6,3,2,1 Out to spinal cord ENCODES: force and direction Individual cells control unique direction => combined to form one direction ex _ + | = / |
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Term
| Cerebellum and Motor Control |
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Definition
| Coordinates muscle movements |
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