SF2 Unit 4 Memorization Flashcards
(565 cards)
1
Q
Projection Neuron
A
Second-order neuron with axon in Ascending Spinothalamic Tract
2
Q
Interneurons: Inhibit or Excite Projection Neurons
A
inhibit (when active)
3
Q
Neurotransmitters used by Nociceptors on projection Neurons
A
Gluatamate
Substance P
Calcitonin Gene-Related Peptide (CGRP)
4
Q
Classes of Endogenous Opioids
A
Enkephalins
Dynorphins
Endorphins
5
Q
Type of Receptor: Opioid Receptors
A
G-Protein Coupled
6
Q
C Sensory Fibers
A
from nociceptors
7
Q
Type of Fibers from Non-Nociceptor Receptors
A
A-Alpha or A-Beta
8
Q
Principle opioid in dorsal horn
A
enkephalin (mu receptor type)
9
Q
High concentration of Mu-type Opioid Receptors
A
Periaqueductal Gray
10
Q
Caused of Pain Wind-Up
A
Repeated firing of C-fiber nociceptors
11
Q
Hyperalgesia
A
Abnormally increased sensitivity to pain
12
Q
Released by Microglia during inflammation
A
Interleukins
Brain-Derived Neurotrophic Factor (BDNF)
13
Q
Discussed Types of Non-Opiate Analgesic Drugs
A
Antidepressants
NMDA Receptor Antagonists (ex: Ketamine)
Anticonvulsants
14
Q
Rostral portion of developing neural tube; precursor to Telencephalon and Diencephalon
A
Prosencephalon
15
Q
Diverticulation
A
Process of Rostral Neural Tube differentating and expanding faster than caudal portion
16
Q
Primary cell type in Neocortex
A
Pyramidal Cells
17
Q
Apical dendrite of Pyramidal Cells is in the Cortex. Where does it send inferior axons?
A
Corpus Callosum (white matter tract)
18
Q
Columns (Cortex)
A
Vertical organization / functional unit
19
Q
Columnopathy
A
Disorder of columnar development in Cortex
ex: Autism Spectrum Disorder
20
Q
Primary Center(s) for Olfaction in Cortex
A
Piriform and Entorhinal Cortices
21
Q
Unimodal Association COrtical Area
A
Adjacent to primary cortical area; modality-specific
22
Q
Heteromodal Association Cortex
A
Receive/process input from multiple modalities; “higher-order” function
23
Q
Disconnection Syndromes
A
Impairments in fibers that connect cortical regions
24
Q
Cortical Signs Associated with Dominant Hemisphere Damage
A
Agraphia
Acalcia
Alexia (Pure and other)
25
Acalcia
Inability to perform simple math (Parietal lobe lesion)
26
Alexia w/agraphia. Lesion?
Left angular gyrus (dominant parietal lobe)
27
Pure Alexia. Lesion?
Left occipital lobe and splenium of corpus callosum
28
Typical sign of Damage to Non-Dominant Cerebral Hemisphere
Neglect
29
Construction Apraxia is an early finding in...
Alzheimer's Disease
30
Damage to this structure can typically cause Hypersexuality and Hyperaggression
Amygdala
31
Non-Cortical Lesion which can cause Homonymous Hemianopia
Damage to Internal Capsule or Lateral Geniculate Nucleus
32
Destructive Eye Deviation
Deviation toward lesion.
Lesioned Frontal Eye Field (Area 8)
33
Irritative Eye Deviation
Deviation away from lesion.
Cause: Seizure
34
Apraxia
Loss of ability to carry out voluntary movement despite intact primary sensory, motor, and language areas
35
Cause: Subcortical Apraxia
May occur due to damage to Subcortical Extrapyramidal Motor System or Thalamus
(Cause of false localization of Apraxia to cortex)
36
Frontal Release Sign
Unmasking of Infantile reflexes by Frontal Lobe
Palmar Grasp, Sucking, Glabellar, Snout, Rooting Reflexes (dont memorize)
37
Dorsal Stream of Visual Processing
"Where" Stream
Motion and spatial information travelling dorsally from primary visual cortex to parietal lobe. Area 17 (V1) to Parieto-Occipital Association Cortex (V5)
38
Ventral Stream of Visual Processing
"What" Stream
Information about size, shape, color, etc. Travels ventrally to Temporal Lobe. Area 17 (V1) to Occipitotemporal Association Cortex
39
Object Agnosia
"Classic Agnosia". Loss of ability to recognize objects by sight
40
Cause: Object Agnosia
Damage to Ventral "What" Stream
41
Types of Visual Agnosia Associated with Left Occipital/Temporal Damage
Apperceptive - Failure of Perception
| Associative - Failure of recognition despite accurate perception
42
Prosopagnosia
Loss of ability to subscribe identity to familiar faces
43
Cause: Prosopagnosia
Bilateral damage to Fusiform Gyrus (Occipitotemporal Gyrus)
44
Akinetopsia
"Motion blindness"
45
Cause: Akinetopsia
Damage to lateral part of occipital lobe
46
Other name for Deep White Matter of Cerebral Hemispheres
Centrum Semiovale
47
Main Types of Tracts in Deep White Matter of Cerebral Hemispheres
Association Fibers
Commissural Pathways
Projection Fibers
48
Associational Fibers
Travel within hemisphere only, connecting areas within the cortex
49
Arcuate Fibers (U Fibers)
Connect adjacent cortical areas (gyri)
50
Predominant Association Fiber
Superior Longitudinal Fasciculus
51
Superior Longitudinal Fasciculus
Associational Fiber; Travels from anterior of front lobe to posterior of occipital lobe
52
Arcuate Fasciculus
Subtract of Superior Longitudinal Fasciculus in Dominant Hemisphere
Connects Broca's and Wernicke's Areas
53
Conduction Aphasia
Can speak fluently but incoherent and inappropriate responses.
Result of lesion to Arcuate Fasciculus
54
Inferior Longitudinal Fasciculus
Associational Fiber connecting Temporal and Occipital Poles
55
Cingulum Fibers
Originate from Cingulate Gyrus
Connects emotion centers and Default Mode Network with memory structures (Limbic System/Hippocampus)
56
Default Mode Network
Provides abilities of internal cognition, thought and dialog.
57
"Theory of Mind"
Understanding that we and others have similar motivations. Adjust behavior accordingly.
Structure: Default Mode Network
58
Uncinate Fasciculus
Association Fiber that connects Temporal and Frontal Lobes. Role in empathy and recognition
Uncinated Seizures - emotional affect and olfactory changes
59
Commissural Pathways
Connect the two cerebral hemispheres
60
Predominant Commissural Pathways
Anterior Commissure
Posterior Commissure
COrpus Callosum
61
Anterior Commissure
Commissural pathway connecting temporal lobe, olfactory cortices, and olfactory bulbs.
62
Posterior Commissure
Commissural pathway connecting Pretectal structures (Rostral Midbrain)
63
Corpus Callosum
Commissural pathway which connecting homotypic ("same type") areas of the cortices/hemispheres
64
What can a defect in development or resection of the Corpus Callosum lead to?
Disconnection Syndromes
65
Projection FIbers
Afferent and efferent pathways that carry information between the brain and spinal cord
66
Capsule (Cerebral Structure)
Fiber bundle traveling through space in cerebrum
67
Corona Radiata
Name for structure formed when fibers fan out to fill hemisphere after traversing capsules
68
Internal Capsule
(Projection) Fiber tract between Thalamus and Lenticular/Lentiform Nucleus
69
Parts of the Internal Capsule
Anterior Limb
Genu
Posterior Limb
70
Anterior Limb of Internal Capsule (tracts)
Most tracts to and from frontal lobe. Includes Frontothalamic and frontopontine tracts
71
Genu of Internal Capsule (tracts)
Corticobulbar Fibers
72
Posterior Limb of Internal Capsule (tracts)
Corticospinal, sensory, and visual/optic radiations. Auditory Radiations.
Retrolenticular portion is here somewhere visual/auditory
73
Blood Supply: Anterior Limb of Internal Capsule
ACA
74
Blood Supply: Genu of Internal Capsule
Lenticulostriate Branches of MCA
75
Blood Supply: Posterior Limb of Internal Capsule
Lenticulostriate Branches of MCA
76
This-walled arteries susceptible to stroke in brain
Lenticulostriate Branches of MCA
77
Blood Supply: Basal Ganglia
Lenticulostriate Branches of MCA
78
External Capsule
Lateral to Internal Capsule (separated by Lentiform Nucleus); Contains Cortico-Cortical Projections
79
Cortico-Cortical Projections
Cholinergic axons connecting basal forebrain to other cortical areas. Found in External Capsule
80
Extreme Capsule
Connects Claustrum with the Insular Cortex
81
Function: Claustrum
Conscious, sustained attention
82
Function: Insular Cortex
Consciousness, emotion, empathy, self-awareness, and also "Theory of Mind"
83
Principle Component of the Extrapyramidal Motor System
Corpus Striatum
84
Consists of structures surrounding the COrpus Callosum and the Upper Brainstem-Diencephalic Junction
Limbic Cortex
85
Function: Limbic System
HOME
Homeostasis, Olfaction, Memory, Emotion
86
Receives precortical input from all sensory systems except olfaction
Thalamus
87
Internal Medullary Lamina
White matter tract dividing Thalamus into 3 (medial, anterior, lateral nuclear groups)
88
Lateral-Posterior Nuclei of Thalamus
Ventral Posterolateral (VPL)
Ventral Posteromedial (VPM
Lateral Geniculate
Medial Geniculate
89
Medial-Posterior Nuclei of Thalamus
Lateral Posterior
Lateral Dorsal
Pulvinar
90
Functional Divisions of Thalamus
Anterior/Medial: Limbic
Anterior/Lateral: Motor
Posterior/Medial: Multimodal
Posterior/Lateral: Sensory
91
Ventral Posterolateral (VPL) Nucleus
Thalamic nucleus; sensory from body (medial lemniscus, spinothalamic tracts)
92
Ventral Posteromedial (VPM) Nucleus
Thalamic nucleus; Sensory from head (Trigeminal sensory pathway)
93
Lateral Geniculate Nucleus
(Thalamus) Target for retinal axons. Optic radiations to Primary Visual Cortex
94
Medial Geniculate Nucleus
(Thalamus) Sends auditory radiations to Primary Auditory Cortex
95
Typical trend with Thalamic syndromes
Association with sensation and pain
96
Paresthesia
Aberrant positive sensations (tingling/numbness)
97
Dejerine-Roussy Syndrome
Thalamic Pain Syndrome
Initial presentation complete contralateral lack of sensation. Progression to severe pain. Typically from stroke
98
Dysesthesia
Abnormal, unpleasant sense of touch.
| Thalamic sign
99
Allodynia
Subtype of Dysesthesia. Painful sensation induced by normally-innocuous stimuli
Possible thalamic sign
100
Hemianesthesia
Contralateral loss of sensation
Could be from damage to VPL or VPM
101
Cortical area remodeled by chronic pain
Prefrontal Cortex
102
Catecholamin-o-Methyltransferase
Gene/protein involved in pain sensitivity. Regulates enkephalin and catecholamines
103
Frank Congeital Insensitivity to Pain
Complete lack of A-delta and C fibers. Lack affective component of pain
104
Congenital Indifference to Pain
Can distinguish sharp/dull pain. Indifferent to sensations. Lack emotional responses, discomfort, and normal withdrawal from pain.
Normal peripheral fibers
105
Congenital Insensitivity to Pain w/Anhydrosis
Lack pain fibers due to a receptor mutation (cannot bind Nerve Growth Factor). Mutated TRK Receptor makes carrying pain impulse difficult. Difficulty responding to tissue damage/infection
106
TRK Receptors
Nerve Growth Factor (NGF) receptor found on Nerve and Mast Cells.
107
Importance of Mu Opioid Receptor
Most analgesics require Mu activation to work
108
Naloxone
Antagonizes and block Mu opioid receptor
109
Mechanisms of the Placebo Effect
1) Decreased awareness in pain sensitive regions
| 2) Increased activity in areas involved in top-down pain suppression
110
Receives projections from Periaqueductal Gray. Abundants 5-HT neurons. Descending projections modulate response to noxious stimulus in Dorsal Horn neurons
Dorsal Raphe Nucleus
111
Nociceptive Pain
Pain transmitted to CNS from peripheral receptors
112
Neuropathic Pain
Pain likely derived from nerve injury in CNS/PNS
113
Phantom Pain
Pain memory. Continuing pain after amputation
114
Most prominent gray matter loss in Chronic Pain
Dorsolateral Prefrontal Cortex
115
Timeline of Behavioral Effects of Chronic Pain
Stage 1: Acute Pain
Stage 2: Learned Helplessness
Stage 3: Acceptance of "Sick Role"
116
FDA-approved SNRIs for peripheral diabetic neuropathy
Venlafaxine and Duloxetine
117
Stroke
Acute impairment of blood supply
118
Ischemic Stroke
Loss of blood supply to regions of brain, leading to infarction
119
Infarction
Tissue death (necrosis) from lack of blood supply
120
Broad categories of Ischemic Stroke
Embolic and Thrombotic Stroke
121
Embolic Stroke
Masses (cholesterol/plaques) travel through circulatory system to block small diameter brain vessels
122
Thrombotic Stroke
Build-up of Atherosclerotic plaques within vessel walls. Gradual occlusion (as opposed to sudden)
123
Treatment: Ischemic Stroke
Tissue Plasminogen Activator (tPA). Can break-up clots if administered within 3 hours
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Hemorrhagic Stroke
Weakening of blood vessel walls leads to rupture then bleed
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Intracerebral Hemorrhage
Internal bleeding in the brain
126
Subarachnoid Hemorrhage
Rupture of surface blood vessels and build-up of blood/pressure in subarachnoid space. Characterized by sudden onset and 'Thunderclap Headache'
127
Neonatal Intraventricular Hemorrhage
Bleeding into the ventricles. Elevated risk in premature / low birth weight infants due to autoregulation difficulty
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Presentation: Neonatal Intraventricular Hemorrhage
Seizure, altered consciousness, and coma
129
Epidural Hematoma
Occasionally follows spontaneous hemorrhage. Rupture of Middle Meningeal Artery. Hematoma does not cross suture lines
130
Subdural Hematoma
Rupture of bridging veins. May cross suture lines
131
Hematoma seen in Shaken Baby Syndrome
Subdural Hematoma
132
Intraparenchymal Hemorrhage
Result of systemic/chronic hypertension. Can be secondary to reperfusion injury after ischemic stroke. Commonly impacts putamen, pons, thalamus, and cerebellum
133
Defining Feature: Charcot-Bouchard Microaneuryisms
Intraparenchymal Hemorrhage
134
Typical rupture in Intraparenchymal Hemorrhage
Lenticulostriate Branches of MCA
135
Ischemic Core
Area immediately impacted by loss of blood flow. Difficulty maintaining ionic homeostasis. Neurons fire in massive bursts (anoxic depolarization)
136
Anoxic Depolarization
Massive bursts of neuronal activity in Ischemic Core
137
Ischemic Penumbra
Periphery of Ischemic core; can be recruited into necrotic area if blood supply not returned
Excitotoxicity from Ca2+ and Glutamate released by Anoxic Deplorization in core.
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Peri-Infart Depolarizations
Ischemic Penumbral neurons undergo successive rounds of depolarization for hours/days after initial event. Due to local Calcium and Glutamate increase
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Cortical Spreading Depression
Region outside of Ischemic Core+Penumbra. Shorter depolarizations, Can go without damage
140
Eosin
Pathognomic (condition-specific) stain for stroke-lesioned brain tissue. "Dead reds"
141
Immediate imagery in stroke
Non-Contrast CT scan. Used to rule out Hemorrhagic Stroke prior to tPA administration
142
Imagery to localized stroke
CT scan or Diffusion-Weighted MRI
143
Cause: Cerebral Hypoperfusion
Typically heart failure
144
Cause of Syncope (fainting)
Cerebral Hypoperfusion
145
Lacunar Infarct
Stroke at terminal point of small artery resulting in small infarcted area
146
Watershed Infarct
Occlusion between two major arterial distributions. Combined symptoms from both supplies.
Ex: MCA/PCA
147
Transient Ischemic Attack
Acute episode typically resolved within 30 mins or up to 24 hours. Predictive of major stroke
148
Amaurosis Fugax
"Veil" coming down over one eye. Occlusion of Central Retinal Artery. Indicative of Transient Ischemic Attack
149
Abulia
Loss of willpower / ability to act voluntarily
150
Akinetic Mutism
Slowed/absent body movement and/or speech
151
Cause: Urinary Incontinence
ACA Stroke (genital representation on homunculus)
152
Area of Hippocampus sensitive to Ischemic Hypoxia
CA1 (pyramidal excitatory neurons)
153
Reason for Macular Sparing in PCA stroke
That part of the occipital lobe receives dual MCA/PCA supply
154
Occlusions associated with Thalamic Stroke
1) Penetrating Branches of PCA
2) Posterior Communicating Artery
3) Anterior Choroidal Artery
155
Weber's Syndrome
Basal Midbrain Sydrome
156
Claude's Syndrome
Tegmental Midbrain Sydrome
157
Benedikt's Syndrome
Weber + Claude's Syndrome
158
Wallenburg's Syndrome
Lateral Medullary Syndrome
159
Typical Signs in Cerebellar Stroke
Inabiltiy to walk and ataxia. Also: dizziness, headache, nausea, vomiting
160
Four Brain Waves
Alpha, Beta, Delta, Theta
161
Beta Waves
Smallest amplitude. 13-30 Hz Associated with mental activity, alert wakefulness, and REM sleep
162
Alpha Waves
8-13 Hz. Relaxed wakefulness. Most prominent over Parietal and Occipital Lobes.
163
Theta Waves
4-8 Hz. Most prominent in the young > adult. Awake, drowsy and non-REM sleep states
164
Delta Waves
0.5-3.5 Hz. Non-REM sleep
165
Current Sink
Transient, local excess of (-) charge
166
Current Source
Transient, local excess of (+) charge
167
Determinant of EEG amplitude
Synchronization of firing
168
Sensory Evoked Potential
Average of EEGs recorded during the sensory stimulus
169
Seizures
Caused by abnormal patterns of neuronal activity
170
Epilepsy
Set of diseases characterized by chronic, repeated seizures
171
Partial Seizure
Restricted to one area of the brain
172
Simple Partial Seizure
Retain consciousness but may experience unusual feelings/sensations
173
Complex Partial Seizure
Change of consciousness, including dreamlike experience or loss of consciousness. May be accompanied by Automatisms
174
Automatisms (Seizures)
Repetitious behaviors such as blinking, twitches, mouth movements, walking in a circle
175
Aura
Sensation warning of impending seizure
176
Secondary Generalizations
Spreading of Partial Seizure from well-defined focal area to involve other brain areas
177
Generalized Seizures
Abnormal activation of many areas of the brain. Loss of consciousness. May trigger falls, loss of muscle tone, or massive muscle spasms.
178
Absence Seizures
Appear to be staring into space; may exhibit muscle jerking or twitching
179
Tonic Seizures
Stiffening of muscles esp: back, legs and arms
180
Clonic Seizures
Repetitive jerking movements of muscles on both sides of the body
181
Atonic Seizures
Loss of normal muscle tone; patient may fall down
182
Tonic-Clonic Seizures.
Stiffening of muscles esp: back, legs and arms. Repetitive jerking movements of muscles on both sides of the body (COMBINATION OF TWO)
183
Postictal Depression
Period of depression, with disorientation, drowsiness, or confusion, and altered EEG which may follow a seizure
184
Medication for Epilepsy
Approach 1: Barbiturates and Benzodiazepines. Attempting to enhance GABA neurotransmission
Approach 2: T-Type Ca2+ Channel and/or Use Dependent Voltage-Gated Na+ Channel Blockers. Reduce neuron ability to generate action potential bursts.
185
Surgery for Epilepsy
Temporal Lobe Resection. Most effective with focal epilepsy. Remove part or all of corpus callosum
186
Rare childhood epilepsys for which CBD is a treatment
Lennox-Gastaut Syndrome and Dravet Syndrome
187
Blood Supply: Inner Retina
Central Retinal Artery
188
Blood Supply: Choricocapillaris
Ciliary Arteries (branch of Opthalmic)
189
Muller Glia
Have cell bodies in Inner Nuclear Layer (Retina). Thought to be involved in synaptic formation
190
Primary Targets of Retinal Projections
Lateral Geniculate Nucleus
Superior Colliculus (midbrain)
Prectectum
Hypothalamus
191
Blood Supply: Lateral Geniculate Nucleus
Anterior Choroidal Artery + Small Branches PCA
192
Geniculocalcarine Tract
Primary visual pathway in brain. Connects LGN to Primary Visual Cortex. Tract fibers, known as optic radiations, travel through Retrolenticular Portion of the Posterior Limb of Internal Capsule
193
Divisions of Geniculocalcarine Tract
1) Upper Division (lower half of visual field); ends at Cuneus Gyrus (Upper Area 17)
2) Lower Division (upper half of visual field); ends at Lingual Gyrus (Lower Area 17)
194
Extrastriate Visual Pathways
Projections from Area 17 to Secondary Association Cortical Areas
195
Prestriate Cortex
Secondary Visual Cortex. V2. Both visual streams connect here to refine information from V1.
196
Superior Colliculus
Main player in Extrageniculate Pathway. Highly-sensitive to moving visual stimuli
197
Regulates control of Saccades (high velocity eye movements)
Superior Colliculus
198
Point of connection of Optic Tract to Superior Colliculus; Superior Colliculus to LGN
Brachium of Superior Colliculus
199
Extrageniculate Pathway
Retina -> Superior Colliculus -> Pulvinar -> Extrastriate Cortex
Works parallel to Geniculocalcarine Tract. Assimilates different types of information to construct objects in visual space
200
Regulates eye's response to ambient light changes
Optic projection to Prectectum, then onward to Edinger-Westphal Nucleus
201
Edinger-Westphal Nucleus
Input from Pretectum. Regulates preganglionic parasympathetic fibers projection to eye.
1) Pupil Constriction
2) Lens Accomodation
3) Eye Convergence
202
Retinal projection to Hypothalamic
Goes to Suprachiasmatic Nucleus (Anterior Ventral Portion of Hypothalamus).
Involved in regulation of Circadian Rhythm and Hormonal Cycles
203
Progressive Encephalization
Evolutionary shift from retinal to primary cortical and then to higher-order visual processing
204
Binding Mechanism (Visual)
Combining multimodal sensation to create perception of external world
205
Cortical Blindness
Loss of conscious perception. Caused by lesion of Area 17 / V1
206
Blindsight
Ability to respond to visual stimuli even with Cortical Blindness. Thought to occur through Extrageniculate Pathway
207
Anton's Syndrome
a.k.a. Visual Anosognosia
Patient denies losing vision despite Cortical Blindness
208
Achromatopsia
Disorder of color perception. Different from color agnosia/anomia because perception happens but failure to identify
209
Cause: Achromatopsia
Fusiform gyrus lesion (V4)
210
Metamorphosia
Distortion of size and shape. Lesion of Inferior or lateral visual association cortex
211
Balint's Syndrome
Characterized by Simultagnosia, Optic Ataxia, and Ocular Apraxia.
Lesion: Bilateral lesion of Dorsolateral Parieto-Occipital Cortex (Dorsal Stream)
212
Simultagnosia
Perception of only a portion of visual field at a time; random shifting.
213
Optic Ataxia
Lack of coordination between visual input and hand movements. Inability to reach out and grab objects
214
Ocular Apraxia
Impaired gaze direction; difficulty initiating saccades
215
P-Type RGCs
(90% of RGCs) Small receptive field, sustained responses. Best suited for fine detail and color
216
M-Type RGCs
Large receptive field. Detection of motion
217
Non-M Non-P RGCs
Color-sensitive (???)
218
Relay Neurons in Lateral Geniculate Nucleus
Magnocellular LGN Neurons (correspond to M-Type RGCs)
Parvocellular LGN Neurons (P-Type RGCs)
Intralaminar LGN Neurons (Non-M Non-P RGCs)
Release glutamate at synapses
219
Stellate Cells (Visual)
Receive input from Lateral Geniculate Nucleus in Layer 4 of Primary Visual Cortex)
220
Blobs
Areas of high Cytochrome Oxidase concentration. Neurons in blobs have wavelength-sensitive repsonses to visual stimuli. Important in color discrimination
221
Channels for Information Processing in Primary Visual Cortex
1) M-Channel Neurons
2) Parvocellular, Interblob (P-IB) Channel Neurons
3) Blob Channel Neurons
222
M-Channel Neurons (Visual Processing)
Analyze motion.
Circular center-surround receptive fields; monocular; wavelength insensitive
223
Directionally Selective Cells
Allow for analysis of objects in motion
224
Simple Cells (Visual)
Orientation selective; respond to stimuli in specific angle in "on" zone
225
P-IB Channel Neurons
Analyze object shape/form. Contain Complex Cells
226
Complex Cells (Visual)
Highly orientation selective; No "on" and "off" zones; respond to stimulus anywhere in receptive field; small receptive field
227
Blob Channel Neurons
Analyze color
P-type and Non-M Non-P Type RGCs project; wavelength sensitive; circular receptive field (others are elongated); not orientation or direction selective
228
Hyper Column
Small cube of visual cortex containing...
1) complete set of orientationcolumns
2) input form both eyes (complete set of ocular dominance columns)
3) All three information processing channels
229
Parallel Activation Theory
Visual info processed in parallel areas of visual system. Perception involves binding of activity in areas processing specific aspects of a single visual object
230
Consequence of missing Critical Period in development of visual cortex
early childhood
LGN axon terminals fail to properly innervate Cortical Layer 4
231
Retinal Disparity
Mechanism for Near-Field Depth Perception (less than 30 m)
At close range, left and right retina images different; binocular neurons provide basis
232
Mechanisms of Far-Field Depth Perception
1) Size (of object)
2) Interposition
3) Linear Perspective
4) Light/Shadow
5) Motion Parallax (nearby objects appear to move faster than distant objects)
233
Fovea
Portion of retina with only cones; responsible for high visual acuity
234
Macula
Yellow, oval-shaped region surrounding fovea
235
Papilledema
Swelling of optic disc in response to increased ICP
236
Non-Papilledema Causes of Optic Disc Swelling
1) Long-term hypertension swells retinal vessels
| 2) Optic Neuritis
237
Optic Neuritis
Inflammation of the Optic Nerve. Presents with abnormal pupillary light reflex (Relative Afferent Pupillary Defect too). Common sign in Multiple Sclerosis (typically unilateral and transient)
238
Relative Afferent Pupillary Defect
One eye sluggish in comparison to unaffected eye during pupillary light reflex
239
Possible cause of Optic Atrophy
Chronic disc swelling
240
Arterio-Venous Nicking
(Fundus abnormality) Chronic hypertension stiffens and thickens arteries, leading to vein indentation and displacement.
241
Cotton Wool Spots
(Fundus abnormality) Microinfarcts result in Retinal Ganglion axonal damage. Axoplasmic material builds up in nerve fiber layer.
242
Hollenhorst Plaque
Cholsterol plaque in the retina (common in geriatric patients with carotid artery disease)
243
Monocular vision loss with "Cherry-red" spot at fovea
Central Retinal Artery Occlusion
244
Retinal Detachment
Merging of posterior neural retina and cell processes from Retinal Pigment Endothelial layer in embryonic development. These layers get separated.
Blindness in affected area. Associated with head trauma, cataract surgery (complication), and Shaken Baby Syndrome
245
Primary Types of Retinal Detachment
1) Rhegmatogenous
2) Tractional
3) Exudative
246
Rhegmatogenous Retinal Detatchment
(Most common form) Hole/tear in retina allows fluid to accumulate underneath. Risk increases with age (liquification of Vitreous)
247
Tractional Retinal Detachment
Scar tissue on the surface of retina may prompt detachment. Typically in patients with poorly-controlled diabetes
248
Exundative Retinal Detachment
Fluid accumulation beneath retina without hole or tear.
249
Scotoma
Abnormal blind spot caused by focal lesions in retina
250
Hemianopia
Loss of 1/2 of visual field along vertical median
251
Quadrantopia
Decreased vision/blindness in 1/4 of visual field
252
Commonality in lesion causing Homonymous Hemianopia/Quadrantanopia
Both are Retrochiasmal lesions
253
Visual issue present in Congenital Hydrocephalus (3rd ventricle)
Binasal Hemianopia
254
Internal Carotid Artery pushing up against optic fibers can cause what deficit
Binasal Hemianopia
255
Binasal Hemianopia
Lesioning of uncrossed temporal retinal fibers
256
Bitemporal Hemianopia
Lesion of the crossed nasal retinal fibers / optic chiasm
257
Four causes of Bitemporal Hemianopia
Pituitary Adenoma
Meningioma
Hypothalamic Glioma
BERRY ANEURYSM in ACA
258
Cause: Contralateral Superior Quadrantanopia
Lower Division of Geniculocalcarine Tract Disrupted at Meyer's Loop
Temporal lobe lesion, LGN innervation of Lingual Gyrus is disrupted
259
Cause: Contralateral Inferior Quadratanopia
Upper Division of Geniculocalcarine Tract disrupted.
Parietal lobe lesion in upper territory of MCA. LGN innervation of Cuneus Gyrus disrupted.
260
Motor Subsystems
1) Pyramidal Motor System
2) Extrapyramidal Motor System
3) Cerebellar Stuff
261
Functions: Extrapyramidal Motor System
1) Motor Programming (planing, initiating, maintaining vol. movements)
2) Habitual Behaviors (procedural learning)
3) Small role in cognition and emotion
262
Key Structures of the Extrapyramidal Motor System (name 5)
1) Caudate Nucleus
2) Putamen
3) Globus Pallidus
4) Subthalamic Nucleus
5) Substantia Nigra
263
Make up Lentiform Nucleus
Putamen and Globus Pallidus
264
Make up Neostriatum (Dorsal Striatum)
Caudate and Putamen
265
Make up Corpus Striatum
Caudate, Putamen, and Globus Pallidus
266
Division of Substantia Nigra featuring lots of melanin
Pars Compacta
267
Subdivisions of the Substantia Nigra
1) Pars Compacta (SNc)
| 2) Pars Reticularis (SNr)
268
Neostriatal Afferent Pathways
1) Cortico-Striatal Pathway [Excitatory/Glutamatergic]
2) Nigro-Striatal Pathway [Modulatory/Dopaminergic]
3) Thalamo-Striatal Pathway [Excitatory/Glutamatergic]
269
Neostriatal Efferent Pathways
Both Inhibitory and GABAergic!
1) Globus Pallidus -> Thalamus
2) Neostriatum -> SNr
270
Function: Medium Inhibitory Spiny Neurons
Inactive in both pathways (Direct/Indirect) when there is no movement
271
Function: GPi-Thalamic Inhibitory Projections
Prevent undesired movement and are tonically-active
272
How do you get movement in the Extrapyramidal Motor System?
Thalamic disinhibition
273
Direct ("Go") Pathway
Projects from Striatum directly to GPi or SNr, then onto Thalamus
274
D1 / D2 Receptors Role in Direct and Indirect Pathways
Direct - dopamine released onto D1 receptors is excitatory
| Indirect - dopamine is inhibitory on D2 receptors
275
Characteristic degeneration in Parkinson's Disease
Dopaminergic neurons projecting from the SNc to Neostriatum [Nigrostriatal Pathway]
276
Motor Symptoms of Parkinson's (5)
1) Resting Tremor
2) Cogwheel rigidity
3) Bradykinesia -> Akinesia (progression)
4) Postural Instability
5) Speech and Swallowing difficulties
277
Myoclonus
Involuntary muscle jerkes (agonist muscle)
278
Essential Tremor
other names: Familial, benign, or senile
(most common) Tremor of upper extremities, head, tongue, lips, vocal cords
279
Resting Tremor
Occurs when limbs relaxed, decreases/disappear during movement. Key feature of Parkinsons'. Typically upper extremities
280
Intention/Ataxic Tremor
Produced with purposeful movement toward a target. Worsens when nearing target
Associated with Cerebellar Disease
281
Postural Tremor
Occurs when limbs actively held in position; disappears at rest
Associated with MS
282
Genetic Defect in Autosomal Dominant Parkinson's Disease
Alpha-Synuclein Protein/Gene
283
Lewy Bodies
Alpha-synuclein aggregates form eosinophillic cytoplasmic inclusions in neuronal body
284
Lewy Neurites
Fibrils of insoluble alpha-synuclein polymers deposit in neuronal processes, astrocytes, and oligodendrocytes
285
Pathological abnormality in SNc Neurons in Parkinson's Disease
Abnormal iron accumulation
286
Adjunct therapies to L-Dopa in Parkinson's
Monoamine Oxidase (MAO) Inhibitors [Slow L-Dopa Breakdown]
Catechol-o-methyltransferase (COMT) Inhibitors [Slow dopamine breakdown]
287
On-Off Phenomenon (Parkinson's)
High dose of L-dopa leads to dyskinesia followed by freezing behavior when drug availability decreases
288
Class of Drugs which can induce Parkinson's-Like Symptoms
Anti-psychotics (rigidity and hypokinesia)
289
Wilson's Disease
Copper metabolism disease, causing progressive liver and basal ganglia degeneration. Similar but presents earlier in life than Parkinson's
290
Distinguishing features of Wilson's Disease from PD
1) Kayser-Flesicher Rings in Cornea (asymptomatic)
| 2) Choreocathetosis (involuntary twitching/writhing)
291
Huntington's Disease
Autosomal dominant progressive neurodegenerative disease. Heavily impacts Striatum.
Atrophy of caudate makes ventricles appear large; progressed disease show atrophy of cortex
292
Primary Target of Huntington's Disease
Enkephalin-containing Neurons of Indirect (motor) Pathway.
Decrease thalamic inhibition, increase excitation -> Hyperkinetic
293
Symptoms of Huntington's Disease
All four basal ganglia functions
```
Choreiform movement
Athetosis
Dementia
Tics
Dystonic Posturing
Psychiatric disturbances
```
294
Ballismus
Wild flinging movement of extremities. Basal ganglion lesion (Commonly: Subthalamic nucleus lesion). Hyperkinetic effect (reduced inhibition)
295
Hemiballismus
(Most Common). Unilateral (contralateral) flinging movements.
Cause: Unilateral lesion of Subthalamic Nucleus
296
Dystonia
Abnormaldistored posturing of limbs, trunk, or face due to sustained contraction of muscles
297
Treatment for Focal Dystonia and types its been successful for
BOTOX
Torticollis - Cervical Muscles
Blepharospasm - Orbicularis Oculi
Spasmodic Dysphonia - Vocal Muscles
298
Athetosis
Writhing, twisting of limbs, face or trunk
299
Chorea
Fluid or jerky movements of varying quality
300
Tics
Urge to perform sudden brief action; relief following performance. Can be motor and/or vocal
includes Gilles de la Tourette's Syndrome
301
Fiber Types: Cerebellar Peduncles
Superior - Afferent/Efferent
Middle - Only afferent
Inferior: Afferent/Efferent
302
Afferents in Superior Cerebellar Peduncle
Ventral Spinocerebellar Tract
Trigeminal Input
Tectocerebellar Input
Coeruleocerebellar Input
303
Efferents in Superior Cerebellar Peduncle
1) Regulate Rubrospinal Tract via Red Nucleus
| 2) Regulate Corticospinal UMNs via VL
304
Afferents in Middle Cerebellar Peduncle
Pontocerebellar fibers to Neocerebellum
305
Subdivision of Inferior Cerebellar Peduncle
Juxtarestiform Body (contains the efferents of the Inferior Ped)
306
Afferents in Inferior Cerebellar Peduncle
Spinocerebellar System (dorsal, cuneo, and rostral types)
Vestibular System
Afferent from Reticular Formation
Trigeminal System
307
Efferents in Inferior Cerebellar Peduncle (all in Juxtarestiform Body)
Fastigial Nucleus and Folcculonodular lobe.
All to UMNs of Vestibular/Reticular Systems
308
Major Cellular Layers in Cerebellum (Deep to Superficial)
1) Granule Cell Layer (Tightly packed layer of excitatory interneurons)
2) Purkinje Cell Layer (Purkinje Cell Bodies)
3) Molecular Cell Layer (Location of majority of synapses)
309
Contents of Molecular Cell Layer (Cerebellum)
Unmyelinated Granule Cells Axons
Purkinje Dendrites
Interneurons
310
Cerebellar Inputs
1) Mossy Fibers (Excitatory)
| 2) Climbing Fibers (Excitatory)
311
Mossy Fibers
Excitatory. Ascend through cerebellar white matter to synapse on Granule Cell denrites
312
Granule Cells
Send axons to Molecular Layer, bifurcate to form Parallel Fibers
313
Function: Parallel Fibers
Form excitatory synapses with Purkinje Cells
314
Climbing Fibers
Excitatory. Project exclusively from contralateral Inferior Olivary Nucleus.
Wrap around cell body and proximal dendritic tree of Purkinje Cell. Module Purkinje cell response to input from parallel fibers.
315
Only Cerebellar Output (from the layers)
Purkinje Cells
316
Cerebellar Inhibitory Interneurons
1) Basket / Stellate Cells
| 2) Golgi Cells
317
Basket Cells and Stellate Cells
Inhibitory interneurons which reside in molecular layer (Cerebellum). Synapse on Purkinje cells. Input from Parallel Fibers.
318
Function: Basket/Stellate Cells (Cerebellum)
Promote lateral inhibition of adjacent Purkinje Cells
319
Golgi Cells
Reside in Granule Cell Layer (Cerebellum), Dendrites project to Molecular Cell Layer. Receive input from Parallel fibers. Axons relay back in Granule Cell Layer.
320
Function: Golgi Cells
Feedback inhibition on Granule Cells
321
Purkinje Cell Ouput: Excitatory/Inhibitory
Inhibitory
322
Destination of Purkinje Cell Output
Deep Cerebellar Nuclei (exception: Vestibular Nuclei)
323
Deep Cerebellar Nuclei (Lateral to Medial)
1) Dentate Nuclei
2) Interposed Nuclei (Emboliform + Globose Nuclei)
3) Fastigial Nuclei
324
Dentate Nuclei
Project to:
1) Red Nucleus
2) VL (Thalamus)
3) Inferior Olivary Nucleus
325
Interposed Nuclei
Subcomponents: Emboliform + Globose Nuclei
Input: Intermediate part of Cerebellum
Output (via Superior Cerebellar Peduncle):
1) VL (Corticospinal Tract)
2) Red Nucleus (Rubrospinal Tract)
326
Fastigial Nuclei
```
Input:
1) Vermis
2) Flocculonodular Lobe
Output:
1) VL and Tectum (via Sup. Peduncle)
2) Vestibular System (via Inf. Peduncle)
```
327
Cerebellar Afferents
1) Corticopontine Fibers
2) Spinocerebellar Fibers (many subtracts)
3) Inferior Olivary Complex
328
Corticopontine Fibers
Sensory, motor and some visual info from cortex. Brought to ipsilateral Pons via Internal Capsule. Pass through Middle Cerebellar Peduncle into Cerebellum
329
Spinocerebellar Fibers (general)
Information about proprioception, touch, pressure and sensation.
Four Subtracts:
1) Dorsal Spinocerebellar Tract
2) Cuneocerebellar Tract
3) Ventral Spinocerebellar Tract
4) Rostral Spinocerebellar Tract
330
Dorsal Spinocerebellar Tract
Lower Limb + Trunk. Non-conscious proprioception
Ascends: Ipsilateral through Gracile Fasciulus
Synapses: Clarke's Nucleus
Enter: Inferior Cerebellar Peduncle
331
Cuneocerebellar Tract
Upper Limbs + Trunk. Non-conscious proprioception
Ascends: Cuneate Fasciculus
Synapses: Cuneate Nucleus
Enter: Inferior Cerebellar Peduncle
332
Ventral Spinocerebellar Tract
Coordination fo Posture/Lower Limb movement. Double-crosses to stay ipsilateral
Enter; Superior Cerebellar Peduncle
333
Rostral Spinocerebellar Tract
Coordination for Posture/Upper limb movement.
Enter: Inferior Cerebellar Peduncle
334
Cerebellar Afferents from Inferior Olivary Nuclear Complex
Extrapyramidal nuclei project to Cerebellum via olivary nuclei. Olivecerebellar Fibers arise from Medulla. Decussate before entering Inferior Cerebellar Peduncle.
Conveyed by Climbing Fibers to CONTRALATERAL Cerebellum
335
Cerebellar Afferent (Maybe) Playing Role in Essential Tremor
Inferior Olivary Nuclear Complex (Olivocerebellar Fibers)
336
Cerebellar Efferent Functional Areas
1) Lateral Cerebellar Hemisphere
2) Intermediate Part / Paramedian Hemisphere
3) Vermal/Median Zone
4) Flocculonodular Lobe
337
Efferent: Lateral Cerebellar Hemisphere
Movement planning information to contralateral VL Nucleus (Thalamus)
Efferents project from Dentate Nucleus through Superior Cerebellar Peduncle.
Some efferents also go to Parvocellular Red Nucleus (indirect corticospinal system)
338
Efferent: Intermediate Part / Paramedian Hemisphere (Cerebellum)
Coordination of ongoing movements of distal extremities, sent to contralateral VL (Lateral Corticospinal Tract) and Red Nucleus (Rubrospinal Tract)
Efferent project from Interposed Nucleus through Superior Cerebellar Peduncle
339
Efferent: Vermal / Median Zone
Proximal trunk movement information. Efferents project from Fastigial Nucleus.
* To VL and Tectum (via Superior Cerebellar Peduncle)
* To Vestibular Nuclei (via Juxtarestiform Body)
340
Efferent: Flocculonodular Lobe
Vestibulocerebelum influences reflexive equillibrium and balance.
Output to the Median Longitudinal Fascisulus (Ocular Control)
341
Consequence of Damage to Flocculonodular Lobe
Nystagmus and Vertigo
342
Most common Cerebellar Infarct
PICA Infarct
343
Cerebellar infarct which spares the brainstem
Superior Cerebellar Artery (SCA)
344
Cerebellar Symptoms: PICA Infarct
Headache, acute vertigo, vomiting, gait/limb ataxia, horizontal nystagmus
345
Cerebellar Symptoms: SCA Infarct
Gait/limb ataxia, dysarthria, horizontal nystagmus.
Less common: headache, vomiting, vertigo
346
Truncal Ataxia
Wide-based stance and unsteady, irregular "drunk-like" gait
347
Typical Cerebellar Signs (Don't worry about memorization)
```
Truncal Ataxia
Hypotonia
Ataxia
Intention Tremor
Dysmetria
Nystagmus
Dysdiadochokinesia
Asynergia/Dyssnergia
Cerebellar Dysarthria
Leaning towards side of lesion
```
348
Dysdiadochokinesia
Inability to perform rapid, alternating movements
349
Asynergia/Dyssnergia
Jerky, irregular, arrhythmic movement during planned motor activity
350
Cerebellar Dysarhtria
Slowed, slurred, speech, scanning speech (unpredictable stressors/pauses/etc in speech)
351
Cranial Nerve issue seen in Cerebellar Hemorrhage
CN VI palsy
352
Motor Issues: Cerebellar Vermis Lesion
Effect medial motor system (proximal trunk muscles)
Truncal ATaxia
Ocular Ataxia
Dysarthria
Nystagmus
353
False Localization (reasons) of Ataxia to Cerebellum
Lesion of peduncles and pons can also produce ataxia
354
Friedrich's Ataxia
Neruodegenerative disorder targeting dorsal and lateral columns. Autosomal recessive.
```
Ataxia
Areflexia
Impaired Fine Touch
Vibration issues
Conscious Proprioception effected
Progressive weakness w/ Babinski
```
355
Symptom Triad: Wernicke's Encephalopathy
1) Cognitive Dysfunction
2) Gait Ataxia
3) Nystagmus
356
Medulloblastoma
Malignant, invasive cancer of Posterior Fossa. ~20% of intracranial tumors in young children. Most commonly seen in the Vermis. Tumor may impair CSF flow if grows.
357
Unique Symptom: Medulloblastoma
Tinnitus (ringing)
358
Paraneoplasia
Autoimmune destruction of Purkinje Neurons. Can be secondary to cancer (don't quote me on that)
359
Mnemonic: Functions of the Hypothalamus
HEAL
Homeostasis (Feeding, Temperature, Sleep/wake cycle)
Endocrine (via Pituitary Gland)
Autonomic (regulation via connections to preganglionic neurons)
Limbic (behavioral, emotion, memory)
360
Location: Pituitary Gland
Inferior to Hypothalamus
361
Subdivisions of the Pituitary Gland
1) Anterior Lobe (Adenohypophysis)
| 2) Posterior Lobe (Neurohypophysis)
362
Anterior Lobe of Pituitary Gland (Adenohypophysis)
Contains Glandular Cells that secrete hormones into circulation. Regulated by Hypothalamic factors released into Vascular Polar System at Median Eminence.
Formed from ectodermal cells of developing pharynx (Rathke's Pouch).
363
Posterior Lobe of Pituitary Gland (Neurohypophysis)
Contains axon terminal of Hypothalamic neurons which release hormones directly into circulation. Originates from Prosencephalon embryologically.
364
Regions of the Hypothalamus (Anterior to Posterior)
1) Preoptic (small area above optic chiasm)
2) Anterior (from preoptic region to end of chiasm)
3) Tuberal (Tuber Cinerum and above)
4) Posterior (area above/posterior to mamillary bodies; including them)
365
Zones of the Hypothalamus (Medial to Lateral)
1) Periventricular
2) Medial
3) Lateral
366
Periventricular Zone of Hypothalamus
Thin layer just inside ependymal cell layer of 3rd Ventricle
367
Lateral Zone of Hypothalamus
Includes Medial Forebrain Bunle and fibers from Monoaminergic Nuclei in brainstem to cerebrum
368
Medial Forebrain Bundle
Axonal pathway connection basal forebrain, hypothalamus, and brainstem tegmentum
369
Functional Groups of Hypothalamic Nuclei (7)
1) Feeding and Satiety
2) Sleep and Circadian Rhythms
3) Regulating Factors of Anterior Pituitary Gland
4) Hormone Release from Posterior Pituitary
5) Autonomic Control Centers
6) Memory
7) Thermoregulation
370
(Hypothalamic Nuclei) Feeding and Satiety
```
Lateral Hypothalamic Area (stimulation inc. feeding)
Ventromedial Nucleus (satiety center; stimulation dec feeding)
```
371
(Hypothalamic Nuclei) Sleep and Circadian Rhythms
Ventrolateral Preoptic Area (VLPO)
Tuberomammilary Nucleus
Suprachiasmatic Nucleus
372
Ventrolateral Preoptic Area (VLPO)
(Hypothalamic nucleus) Regulates sleep. Derived from Telencephalon unlike the other nuclei which are diencephalon
Relases GABA and Galanin as inhibitory transmitters
373
Tuberomammilary Nucleus
(Hypothalamic nucleus) Histamine from its neurons project to cerebral cortex. Promotes wakefulness
374
Suprachiasmatic Nucleus
(Hypothalamic nucleus) Receives light input from retina. Master clock for maintaining circadian rhythms
375
(Hypothalamic Nuclei) Regulating Factors Affecting Anterior Pituitary Gland
All projects to Median Eminence where factors are released to control hormone release:
Arcuate Nucleus
Paraventricular Nucleus
Periventricular Area
Medial Preoptic Area
376
(Hypothalamic Nuclei) Regulate hormone release from Posterior Pituitary
Supraoptic Nucleus - released Vasopressin
| Paraventricular Nucleus - releases Oxytocin
377
Vasopressin
aka ADH
Stimulates water retention. Released by Supraoptic Nucleus
378
Oxytocin
Stimulates milk ejection, uterine contractions, maternal behavior and bonding. Released by Paraventricular Nucleus
379
(Hypothalamic Nuclei) Autonomic Control Centers
Descending fibers from these nuclei travel through Medial Forebrain Bundle to PAG and Reticular Formation.
Relay to Preganglionic PArasympathetic nuclei in brainsted/sacral spinal cord and Preganglionic sympathetics in the Intermediolateral column of Thoracolumbar spinal cord.
Paraventricular Nucleus
Lateral Nucleus
Dorsomedial Nucleus
Posterior Nucleus
380
(Hypothalamic Nuclei) Memory
Mamillary bodies receive input from Hippocampal Formation (via Fornix). Project to Anterior Thalamus (Mammillothalamic Tract). Ant Thalamus projects to cingulate gyrus, indirectly going back to hippocampus.
Important circuit for memory formation
381
Hypothalamic Nucleus Degenerated in Wernicke-Korsakoff Syndrome
Mamillary Bodies
382
(Hypothalamic Nuclei) Thermoregulation
Autonomic Functions: Sweating and Altered Blood Flow
Somatic Functions: Shivering and Panting
Anterior Hypothalamus cools, Posterior Hypothalamus heats up
383
Input Types to Hypothalamus
Visceral Sensory (via Medial Forebrain Bundle)
Blood Info
Optic Pathway
Prefrontal/Limbic Areas
384
Output Types from Hypothalamus
Regulation of Preganglionic Autonomics
Control Behavior
Endocrine Function
385
Corticotropin Releasing Hormone (CRH)
Released from Hypothalamus to Anterior Pituitary.
Targets: Preoptic, Supraoptic, Paraventricular Nuclei
386
Corticotropin (ACTH)
aka Adrenocorticotropic Hormone (ACTH)
Released by Anterior Pituitary into general circulation. Stimulates release of corticosteroids from Adrenal Cortex
387
Cortisol Negative Feedback Effect
Inhibits Hypothalamus and Anterior Pituitary
388
Pituitary Adenoma
Benign, slow-growing tumor of pituitary gland. 85% cause improper secretion.
*Large adenoma may compress optic chiasm -> Bitemporal Hemianopia*
389
Panhypopituitarism
Deficiency of all pituitary hormones. Occurs due to tumor, infarction, autoimmune disorders, or chemotherapy.
Requires hormone replacement therapy
390
Mnemonic: Functions of Limbic System
HOME
Homeostasis
Olfaction
Memory
Emotion
391
Cortical Structures of Limibic System
```
Parahippocampal Gyrus (incl. Entorhinal Cortex)
Cingulate Gyrus
Insular Cortex
Orbitofrontal Cortex
Prefrontal Association Cortex
Hippocampus
```
392
Subcortical/Diencephalic Nuclei of Limbic System
Amygdala
Ventral Striatal Structures
Thalamic Nuclei (Anterior and Mediodorsal Nucleus)
Hypothalamic Nuclei (Anterior, POsterior and Mamillary Nuclei)
393
Midbrain Structures of Limbic System
Ventral Tegmental Area (below substantia nigra)
394
Entorhinal Cortex
Area 28. Part of Parahippocampal Gyrus. Major relay for I/O between Association Cortex and Hippocampal Formation. Part of Papez Circuit
395
First cortical area to degenerate in Alzheimer's Disease
Entorhinal Cortex
396
Hippocampal Formation
Part of Parahippocampal Gyrus. Medial Temporal Lobe. Stores and processes spatial info. Formation of episodic memory.
Consists of: Subiculum, Hippocampus, and Dentate Gyrus
397
Dentate Gyrus
Role in memory disorders and possibly depression. Part of Hippocampal Formation. Undergoes neurogenesis throughout life.
398
Intrinsic Hippocampal Circuit
Association Cortex -> entorhinal Cortex -> Hippocampus -> 3 major targets
1) Medial and Lateral Nuclei
2) Lateral Septal Nucleus
3) Anterior Thalamic Nucleus
399
Alvear and Perforant Pathways
Part of Intrinsic Hippocampal Circuit. Carry fibers from Entorhinal Cortex to Hippocampus
400
Fornix
Carries axons out of Hippocampus in Intrinsic Hippocampal Circuit. Curves around ventricular system to Diencephalon and Septal Nuclei
401
Septal Nuclei
Function: Endogenous Reward Circuits
Input: Hippocampus, Amygdala, Hypothalamus, and Ventral Tegmental Area
Located in medial wall of anterior horn of Lateral Ventricles.
402
Location: Amygdala
Anterior Temporal Lobe
403
Function: Amygdala
Interpret and Recall emotional content and olfactory memories, visual inputs, and response. Influences "fight or flight", mood, and emotion.
404
Stria Terminalis
Major output from Amygdala. Connects it to Hypothalamus and Basal Forebrain
405
Amygdala Nuclei
1) Corticomedial Nucleus
2) Basolateral Nucleus
3) Central Nucleus
406
Amygdala Inputs
Highly-processed sensory info (temporal lobe, olfactory, and limbic areas)
Autonomic Input (Orbitorfrontal cortex, cingulate gyrus, hypothalamus, midbrain tegmentum)
407
Amygdala Outputs
Association Cortex and Autonomic Centers (via Stria Terminalis)
408
Symptoms: Amygdala Lesion
Docility
Aggression
Outbursts/Rage
Hyperphagia***
409
Limbic-Brainstem Nuclei Connections
Reciprocal. Associate limbic function with autonomic and behavior arousal processes
410
Function: Basal Ganglia / Limbic Channel
Circuit involved in emotional and motivational drive. Dysfunction leads to neurobehavioral and psychiatric disorders.
411
Medial Diencephalic Structures (Limbic)
Important for memory
Thalamus: Anterior Nuclei and Mediodorsal Nucleus
Hypothalamus: Mammillary Bodies
412
Medial Temporal Lobe Structures (Limbic)
Important for memory. Consists of Entorhinal Cortex and Hippocampal Formation. Reciprocal connections with Multimodal Association Cortex.
413
Bilateral lesion to either Medial Diencephalic Structures OR Medial Temporal Lobe Structures
Loss of declarative or explicit memory
414
Unilateral Lesion to MDS or MTLS (Dominant)
Verbal Memory Deficit
415
Unilateral Lesion to MDS or MTLS (Non-Dominant)
Visual-Spatial Memory Deficit
416
Kluver-Bucy Syndrome
Discovered by removal of Amygdala, Hippocampus, and Anterior Temporal Cortex (bilateral). Similar symptoms from Temporal Resections done for EPILEPSY and Viral Encephalitis
417
Amygdala Hyperactivation Related Disorders
Anxiety
Panic Attack
PTSD
Obsessive-Compulsive Disorder (OCD)
418
Infarct in Superior Portion of Basilar Artery
Significant memory loss.
PCA, which supplies important limbic regions, branches here. Makes it a bilateral infarct.
419
Possible Result of Contusions in Limbic Areas
Contusions more likely than concussion to cause permanent damage. Can lead to seizures
420
Hippocampal Sclerosis
Severe Medial Temporal Lobe lesion causes by seizures. Astrocytic scar formation. Memory loss can persist during seizure-free periods
421
Transient Global Amnesia
Sudden and temporary onset of Retrograde and Anterograde Amnesia. Coincides with extreme physical exertion or emotional stress
422
Degenerates in Progression to Wenicke-Korsakoff Syndrome
MDS Nuclei and Hippocampus. Brings on Amnesia. Confabulation
423
Confabulation
Patient provides random answers to questions without attempting to deceive
424
Categorical Types of Memory
1) Procedural Memory
| 2) Declarative Memory
425
Procedural Memory
Not directly available to conscious awareness. Skills, habits, experience dependent reflex modications.
426
Declarative Memory
Conscious awareness. Autobiographical memories and knowledge.
427
Type of memory impaired with Amnesia
Declarative Memory
428
Retrograde Amnesia
Loss of formed memories. Damage to storage areas
429
Anterograde Amnesia
Inability to form new memories. Damage to areas required for consolidation
430
Immediate Memory
Sum of all sensory input being procesed at cortical level. Function of relevant High-level sensory / Association Area of Cortex
431
Short-Term Memory
Conscious attention allows entrance and required to retain. May involve same cortical areas for immediate memory OR be transferred to Prefrontal Cortex
432
Central Executive Function (memory)
Regulates entry of info into Short-Term Memory
433
Long-Term Memory
Large, resistant to forgetting. Long-term memory stable but memories in process of consolidation vulnerable
434
Consolidation
Thought to occur via strengthening of synapses in Cortical Areas. Makes use of Papez Circuit.
435
Bilateral Damage to Papez Circuit
Causes Global Anterograde Amnesia
Least Severe: Just Hippocampus
Mild: Medial Temporal Lobe structure
Severe: Medial Diencephalic Structures
436
Type of Synapses Seeing LTP
Glutamate Synapses
437
Location of Glutamate Synapses in Brain
Spines of Pyramidal Neurons
438
Targets for Calcium Second Messenger in LTP
1) Protein Kinase C
2) Calcium Calmodulin Dependent Protein Kinase II (CaMK II)
3) Nitric Oxide Synthase
439
Mechanisms Enhancing Post-Synaptic Sensitivity in LTP
1) Phosphorylation of AMPA/KA Receptors
2) Exocytosis of more AMPA/KA Receptors
3) Increase calcium for vesicle release
440
Retrograde Messaging in LTP
Nitric Oxide, release mediated by Calcium in post-synaptic neuron. Enhances Pre-Synaptic Function
441
Reticular System integrates info from all senses except...
olfaction
442
Neurotransmitters most used in Reticular System
Neurons Serotonergic or Noradrenergic
443
Function: Reticular System
Most Important: Consciousness and Arousal
444
Principle Columns of Reticular System
1) Lateral Column
2) Medial Column
3) Median Column
445
Lateral Column of Reticular System
Contains Parvicellular Neurons that receive afferent fibers from neighboring brainstem regions
446
Medial Column of Reticular System
Magnocellular and Gigantocellular neurons that give rise to efferents
447
Median Column of Reticular System
5HT Neurons of the Raphe Nuclei. Involved in modulatory activity throughout Brain + Spinal Cord
448
Reticular Levels working together on Alertness/Consciousness
Diencephalon, Mesencephalon (Rostral Reticular Formation), and Rostral Pons
449
Reticular Levels Working together on Motor, Reflex, Autonomic Function. Also function with CN Nuclei
Caudal Pons (Caudal reticular formation) and Medulla
450
Reticular Nuclei: Telencephalon
Nucleus Basalis of Meynert
451
Reticular Nuclei: Diencephalon
Reticular Nucleus of the Thalamus
452
Reticular Nuclei: Midbrain
Periaqueductal Gray
Dorsal Raphe Nucleus
Ventral Tegmental Area
Substantia Nigra, Pars Compacta (SNc)
453
Reticular Nuclei: Pons
Nucleus Locus Coerulus
| Pedunculo-Pontin Nucleus / Laterodorsal Tegmental Nucleus
454
Reticular Nuclei: Medulla
Nucleus Raphe Magnus
Rostral Ventral Medullar
Nuclei of Medullary Reticular Formation
455
Nucleus Basalis of Meynert
(Reticular System) Selective Attention, alertness and memory processes. Heavily impacted by Alzheimer's.
Input: Ventral Tegmental Area (DA), Raphe Nuclei (5HT), Nucleus Locus Coeruleus (NE)
Output: Project widely to Cortex (bypass Thalamus) and Amygdala (ACh)
456
Reticular Nucleus of the Thalamus
(Reticular System) Gates activity of Thalamocortical Relays and ARAS. Only Thalamic nucleus with no projections outside of Thalamus.
457
Dorsal Raphe Nucleus
(Reticular System) Assists in regulation of consciousness, attention and mood. Widespread forebrain projections with no thalamic relay.
Primary site of 5HT Neurons in Reticular Formation
458
Ventral Tegmental Area
(Reticular System) Memory, attention, motivation.
Part of Mesolimibic DA Reward Pathway (prject to Nucleus Accumbens)
Part of Mesocortical DA Reward Pathway (Project to Cortex)
459
Physiology of Reward Seeking
Dopamine released before the reward is actually received
460
Nucleus Locus Coerulus (Blue Nucleus)
(Reticular System) Ascending/Descending projections to limbic structures, dorsal horn, and cortex.
NE Neurons Modulate: **ARAS**, arousal, selective attention, stress responses, pain modulation, and mood
461
Pedunculo-Pontine Nucleus / Laterodorsal Tegmental Nucleus
(Reticular System) Largest sites of ACh production in brain. Involved in wakefulness, REM Sleep, and ARAS. Widespread cortical projections via Thalamus
462
Reticular Nuclei which must be inhibited for sleep to occur
Pedunculo-Pontine Nucleus and Laterodorsal Tegmental Nucleus
463
Nucleus Raphe Magnus
(Reticular System) 5HT neurons involved in pain modulation. Receives projection from PAG and projects down to Dorsal Horn
464
Rostral Ventral Medulla
(Reticular System) Glutamatergic neurons with descending projections to Spinal Cord. Modulate ascending transmission of pain (similar to PAG)
465
Cardiovascular and respiratory regulation centers
Medullary Reticular Formation
466
Ascending Reticular Activating System (ARAS)
Responsible for consciousness, wakefulness, arousal, and attention. Filters out noise information.
PRIMES cortex to receive sensory input.
SHUNTS information that is life-threatening/frightening to Amygdala
467
Location for many ARAS Nuclei
Ponto-Mesencephalic-Diencephalic Regions of Reticular Formation
468
Main ARAS Pathways
1) Aminergic Nuclei -- activated during woke state
| 2) Cholinergic Nuclei -- wake state and REM sleep
469
Aminergic Nuclei of ARAS
Project Directly to Cortex
1) Nucleus Locus Coerulues (NE)
2) Raphe Nuclei (5HT)
3) Tuberomammillary Nucleus (Histamine)
470
Cholinergic Nuclei of ARAS
Project to Cortex via Thalamus
1) Pedunculo-Pontine Nucleus (ACh)
2) Laterodorsal Tegmental Nuclei (ACh)
471
Minimally Conscious State
Periods of responsiveness/wakefulness with minimal and variable awareness
Visual tracking, sleep/wake cycle, highly-variable EEG
472
Locked-In Syndrome
Lesion preventing corticospinal and corticobulbar motor output. Sensory function and consciousness are spared
473
Catatonia
Abnormality of movement from behavioral / mental problems
474
Pathology/Lesion: Akinetic Mutism / Abulia / Catatonia
Impaired Frontal Lobe and Dopaminergic function. Apathy and deficits in response initation
475
Vegetative State
Periods of wakefulness but no awareness. Persistent vegatative state is more than a month with no evidence of change
No visual tracking
Sleep/wake cycle present but variable
No volutional behavior but may arouse to pain
476
Coma
Prolonged loss of consciousness with severe impairment of Cortical and Diencephalic-Upper Brainstem Activating System Function.
Unresponsive to sensory input but primitive reflex may be present
477
Brain Death
Irreversible unconsciousness with complete loss of brain function and ability to breath
478
Causes of Coma (3)
1) Bilateral Lesion in upper brainstem affecting ARAS
2) Bilateral Compromise/Destruction Brain Hemisphere
3) Large bilateral Thalamus lesion
479
Major Dopamine Pathways in Brain
1) Nigrostriatal Pathway (Extrapyramidal System)
2) Meso-Limbic Projections
3) Meso-Cortical Projections
4) Tubero-Infundibular Projection
480
Meso-Limbic Projections
Major dopaminergic reward pathway.
Ventral Tegmental Area -> Nucleus Accumbens
481
Meso-Cortical Projections
Dopaminergic pathway for working memory and attentional aspects of motor initiation.
Ventral Tegmental Area -> Cortex (mainly Prefrontal)
482
Tubero-Infundibular Projection
Dopaminergic Pathway inhibiting synthesis and release of Prolactin.
Arcuate Nucleus -> Anterior Pituitary
483
"Typical" Anti-Psychotic
Alleviate positive symptoms of Schizophrenia. Exacerbate negative symptoms.
Possible irreversible side effect: Tardive Dyskinesia (involuntary, repetitive movements)
484
"Atypical" Anti-Psychotic
Cause fewewr Extrapyramidal side-effects than "Typical" type.
Complications: Weight gain, Type 2 Diabetes, Prolactinema (hormone secreting tumor)
485
Important Brain Serotonin Pathways
1) Dorsal Raphe Nucleus - modulates mood
| 2) Nucleus Raphe Magnus - modulates CNS Pain transmission
486
Purposes of Sleep (probable)
```
Energy conservation/replenishment
Consolidation
Tissue Restoration
Clear Brain Metabolites
Renormalization of Synaptic Strength/Number
```
487
Controlled by Circadian Rhythms
```
Sleep-Wake Cycle
Hormone Secretion
Blood Pressure
Body Temperature
Urine Production
```
488
Nucleus regulating activity of Pineal Gland
Suprachiasmatic Nucleus
489
Function: Pineal Gland
Secrete melatonin
490
Sleep Load
"Drive" to sleep
491
Brain Waves during Awake State
Beta Waves (high frequency, low amplitude)
492
Sleep Stage 1
Drowsy period.
Theta Waves (slightly lowered frequency, high amplitude)
493
Sleep Stage 2
Lower frequency, higher amp waves than Stage 1. Presence of Sleep Spindles and K-Complex
494
Sleep Spindles
Periodic bursts of activity (1-2 seconds) seen in Sleep Stage 2. Promotes consolidation of motor memory in young adults
495
K-Complex
EEG pattern during Stage 2 sleep every two minutes
496
Sleep Stage 3
Deepest level of Sleep. Slow Wave Sleep (SWS).
Delta Waves (low frequency, high amplitude)
497
EEG and Physiology: REM Sleep
EEG similar to wake state. Increase in BP, HR, and metabolism
498
Characteristic of REM SLeep
```
Dreaming
Visual Hallucinations
Increased Emotion
Lack of self-reflection
lack of volitional control
paralysis of large muscles
penile erection
```
499
REM Rebonund
REM deprivation makes you go straight to REM sleep at next opportunity
500
Activation of Thalamus (sleep)
Causes (test animal) to fall asleep when activated
501
Blocks sensory input during sleep
Thalamus
502
Secreted by Hypothalamus to Promote Waking
Orexin and Hypocretin
503
Central Apnea
Efferent signal to diaphragm insufficient for inspiration. Most common in early NREM sleep.
Ondine's Curse - severe form, breathing stops in sleep
504
Narcolepsy
Excessive daytime sleepiness. Inhibition of generation of REM sleep dysfunctional. Patients lose Orexin/Hypocretin-synthesizing neurons.
Lose muscle control during episodes (cataplexy)
505
REM Sleep Behavior Disorder (RBD)
Kick, punch, and act out aggressive dream scenarios. Mainly men over 50. Associated with inc. incidence of Parkinson's Disease
Brainstem disorder preventing muscle paralysis
506
Sleep/Aging
Sleep lighter and shorter. Need same amount
Less SWS and fewer Sleep Spindles, Pineal gland produces less melatonin. Fewer VLPO neurons.
507
Yerkes-Dodson Law
We function best at moderate level of arousal (stress)
508
Active Pathways During Stress
1) HPA Axis
| 2) Adrenal-Medullary System
509
Physiological Effect of Cortisol
Increase energy mobilization.
| Regulates immune system
510
Adrenal Medullary System
Hypothalamus -> Sympathetics -> Adrenal Medulla -> Release of Norepinephrine
511
Effects of Norepinephrine
Increased HR, Respiration, BP
512
General Adaption Syndrome (Stress)
Stage 1 - react to stress
Stage 2 - adaption to stress; sustained cortisol release
Stage 3 - Depletion
513
Dementia
Progressive memory impairment with at least one of these...
1) Aphasia
2) Agnosia
3) Apraxia
4) Executive Function Disturbance
514
Alzheimer's-Type Dementia
Progressive, irreversible, and uncurable. Plaques, tangle in brain. Early/Late Onset Breakpoint 65 yo. Typically die from infection or aspiration; caused by pneumonia, brain hemorrhage, or compromised BBB
515
Alzheimer's Global Atrophy
Most pronounced in...
Hippocampus, Temporal Lobe, and Frontal Lobe.
Narrowing of gyri, widening of sulci, and enlarged lateral/3rd ventricles
516
Most pronounced type of neurodegeneration in Alzheimer's Disease
Cholinergic Neurons
517
First area to show pronounced loss in Alzheimer's
Entorhinal Cortex (Area 28)
518
Cholinergic-Neuron heavy nucleus degenerating in Alzheimer's and heavily-impacted in all dementias
Nucleus Basails of Meynert
Impaired:
Selective Attention
Cortical Activation
Memory Processes
519
Hallmark Symptoms of Alzheimer's Disease
5 A's
```
Anomia
Aphasia
Apraxia
Agnosia
Amnesia
```
520
Anomia
Deficit in expressive language. Fluent, correct speech. Work hard to avoid forgotten word.
521
Idomotor Limb Apraxia
Most common form of Apraxia in Alzheimer's Disease
522
Alzheimer's Amnesia
Specific loss of...
Episodic Memory
Semantic Memory (what words mean)
Procedural Memory
523
"Sun Downing" or "Late-Day Confusion"
Severe late afternoon/evening mood disturbances observed in AD
524
Later stage Alzheimer's introduces some more severe symptoms...
Inability to respond to environment, control movement, communicate.
Paranoia
Cachexia/Dehydration (forget how to chew/swallow)
Death is typically due to pneumonia or cerebral hemorrhage
525
Pathophysiology List for Alzheimer's
```
Tau Hyperphosphorylation
Amyloid Beta accumulation
Granulovacuolar Degeneration
Cholinergic Degeneration
Glutamatergic Dysfunction
Decrease in Dendritic Shafts, Spines, and Synapse #
Gliosis
```
526
Tau Hyperphosphorylation
Happens within neocortex. Generates Neurofibrillary Tangles (NFTs)
527
Neurofibrillary Tangle Impact (structures) by Stage of AD
Early: Medial Temporal Lobe
Mid: Association Cortex
Late: Primary Cortical Areas
528
Senile Plaques
Plaques formed by Amyloid beta accumulation in Alzheimer's
529
Granulovacuolar Degeneration (GVD)
Fluid-filled space and granular debris that accumulates in neurons in AD
530
Glutamatergic Dysfunction in AD
Amyloid B is toxic to these neurons. Glutamate availability and NMDA receptors are affected
531
Gliosis in AD
Sporadic astrogliosis and localized microgliosis around the Senile Plaques.
532
Precursor to Amyloid B
Amyloid Precursor Protein (APP). Cleaved by Secretases
B and Y Secretases start to cleave in Alzheimer's, producing Amyloid B. Perhaps BBB / perfusion issue??
533
Post-Operative Cognitive Dysfunction
Presents similar to Alzheimer's but suddent onset and transient
534
Early Stage Treatment of AD
Acetylcholinesterase Inhibitors (first line). Mostly just slow decline
535
Acetylcholinesterases used in Early Stage AD Treatment
Donepezil (Aricept)
Galantamine (Razadyne)
Rivastigmine (Exelon)
536
Moderate-Severe AD Treatment
Continue first-line. Add Memantine (Namenda) -- noncompetitive NMDA Antagonist.
Reduces neurotoxicity in Glutamergic dysregulation to minimize neuron death. Minor improvements and slows accumulation of Tau Tangles.
537
Dependence
Need for continued drug use to avoid withdrawal
538
Addiction
Uncontrollable cravings, inability to control use, compulsive use, and use despite harm to self/others
539
Drug Use: Pathway driving Wanting/Drive to Reward
Ventral Tegmental Area (Wanting/Drive) -> Nucleus Accumbens (Reward)
540
Lasting change in chronic drug use in brain
Synapses strengthened and decreased sensitivity to Dopamine
541
Hijacked Brain Centers in Drug Use
Prefrontal / Orbitorfrontal Cortex
Basal Ganglia (Striatum)
Anterior Cingulate Cortex
Amygdala
542
Role of Drug Activation of Amygdala
Adds emotional context to memories
543
Epidemiology
Study of distribution/determinants of health-related states/events in specified populations, and the application of this study to control health problems
544
Major Components Studied in Epidemilogy
1) Frequency of Disease
2) Distribution
3) Determinants
545
Classical Epidemiology
Studies at risk population to prevent disease in total population
546
Incidence
New occurrences of disease, injury, or death during time period
547
Prevalence
Number of patients who have disease -- old and newly-diagnosed -- at a given time
548
Point Prevalence
Prevalence at a certain point in time
549
Period Prevalnce
How many people had disease at any time during the period
550
Screening
Search for unrecognized diseases or health condition by means of rapidly applied tests, procedures, or examinations in apparently healthy individuals.
551
Lead Time
Treatment time advantage gained by screening (period between earliest possible diagnosis and diagnosis point by traditional means)
552
Types of Screening
1) Mass Screening
2) High-Risk Screening
3) Multi-Phasic Screening
553
Validity
Ability of test to distinguish who has disease, and who does not
554
Sensitivity
Ability of test to identify correctly WHO HAVE the disease
555
Specificity
Ability of test to identify correctly who DO NOT HAVE the disease
556
Mass screening test: better sensitive or specific
Sensitive (no need to follow negatives)
557
Tests in Treatment Decisions: better sensitive or specifc
Specific. Don't want to treat false positive
558
Qualitative Studies
Ethnographic observations, open-ended semi-structured interviews, focus groups, and key informant interviews. Review results and identify paterns
559
Cross-Sectional Study
Survey of population at single point in time. Quick.
560
Disadvantages to Cross-Sectional Studies
1) HArd to draw cause-effect about risk factors
| 2) Neyman Bias
561
Neyman Bias
Chronic and milder cases of disease more likely to survive than more aggressive types. Issue with Cross-Sectional Studies
562
Cross-Sectional Ecological Studies
Relate frequency of characteristic and some outcome occuring in same geographic area
563
Types of Bias in Case-Control Studies (4)
1) Confounding Bias
2) Memory Bias (cases tend to remember exposure to risk factor better)
3) Selection Bias
4) Interviewer Bias
564
Selection Biases in Case-Control Studies
1) Sampling Bias
2) Incident-Prevalent Bias
3) Berkesonian Bias
565
Berkesonian Bias
Increases rates of hospitalization due to exposure AND outcome
