Cerebral Cortex Lecture Flashcards

Question

Muscle Spindles

Answer 1

Intramural fibers | -sensory fibers that tell CNS what skeletal muscles are doing

Answer 2

1) Postcentral Gyrus=SENSORY CORTEX - middle cerebral artery supplies Upper Extremity and Face (lips, tongue, teeth, pharynx) - ANterior Cerebral artery supplies Lower Extremity and Head/neck 2) Precentral Gyrus= MOTOR CORTEX - Middle cerebral artery supplies Hand and Face (lips, tongue, swallowing) - Anterior Cerebral artery supplies Upper and Lower extremity (minus Face and Hands)

Answer 3

1) Inability to perform a a purposeful movement w/out paralysis 2) disorder of motor control - may occur after damage in parietal association cortex, premotor cortex, or supplementary motor cortex 3) May affect the muscles of speech - seperate disorder from aphasia

Answer 4

Primary Sensory Cortex (S1) Post central gyrus 3a-Propioception (aware of body parts in space) from muscle spindles 3b+1->-cutaneous afferent 2- Golgi tendon organ and joint afferent

Answer 5

Primary Somatosensory cortex - post central gyrus - Brodmanns area 1,2,3 - 3a=propioception from muscle spindles - 2-golgi tendon organs and joint afferents - 1+ 3b= cutaneous afferents

Answer 6

Primary Motor Cortex (M1) - Brodmans Area 4 - Precentral Gyrus (right Half)

Answer 7

Brodmanns ares 44 and 45 of Left Brain - inferior frontal gyrus - speaking and writing language

Answer 8

Lesions of Frontal inferior gyrus Broca’s area 44 and 45 of Left brain AKA expressive aphasia or nonfluent aphasia 1) Able to comprehend language but can't speak fluently (can't express themselves) - Not paralysis of vocal aparatus - difficulty writing (agraphia) but they can understand written language (read) 2) most common causes: - tumors/occlusion of- frontal M4 branches of middle cerebral artery 3) other Symptoms-contralateral motor signs and symptoms such as - weakness (paresis) of the lower part of face - weakness of the arm - motor weaknesses + aphasia=occlusion of branches from the proximal parts of the middle cerebral artery (M1) including lenticulostriate arteries 4) Full-blown brocas aphasia - doesn't affect just brocas area-> includes insular cortex and white matter 5) Severe Brocas aphasia - unable to speak=mutism - still understand speech, can swallow and breathe normally 6) Less severe case - limited speech is possible - short habitual phrases such as "Hi, fine, thank you, and yes or no are the first to come back 7) Mild Broca aphasia - damage only affects cortical area

Answer 9

To the Right of postcentral sulcus/gyrus Sensory association

Answer 10

Brodmanns areas: - 39=written - 40=connecting - 22=spoken (sometimes) Language center - left side of brain - comprehend spoken or written language

Answer 11

17, 18, 19 - more complex moving towards 19 (inner) from occipital pole - 17=light patterns

Answer 12

Higher order visual audio memories - middle temporal gyrus - memories and language

Answer 13

Brodmann areas-41 and 41 - Primary Auditory Cortex - process what is heard

Answer 14

Primary Gustatory Center - Located below central sulcus above Sylvian fissure - dysgeusia (gustatory illusions)

Answer 15

Parietal Eye field | -eye movement

Answer 16

1) Premotor cortex | 2) Supplemental motor cortex (M2)

Answer 17

Damage up area 19 of visual cortex - has to be bilateral - no color seen or able to imagine

Answer 18

- lesion along inferior temporal sulcus | - cannot perceive motion

Answer 19

Cingulate Sulcus | -medial view

Answer 20

Medial view - deep within central sulcus - receives input from S1 - has strong connection with amygdala and Hippocampus

Answer 21

Medial view - recognizing faces - parahippocampal gyrus - read emotions on someone’s face

Answer 22

Inferior Temporal Gyrus | -higher order visual memories

Answer 23

Inferior Temporal Gyrus | -higher order visual processing

Answer 24

Premotor Cortex - voluntary motor function that is dependent on sensory input - ex: reaching for object in space - involved in planning and executing movements - approx 30% of pyramidal fibers are from here - has strong projections to primary motor cortex (area 4) - receives input from the supplementary motor cortex Lesion: - causes apraxia=cannot perform purposeful movement in the absence of paralysis - pt has difficulty walking and performing other complex motor tasks

Answer 25

Aka (M2) - approximately 5% of pyramidal fibers - involved in planning movement (rather than executing movements) - activated when pt asked to flex multiple fingers in a SPECIFIC sequence (along with m1) - Mental reps (not actually doing reps)

Answer 26

Personal Geography - knowledge of where you are in enviroment - knowledge that your body parts are yours (angular gyrus involved-area 39) Lesion: - cannot learn a new enviroment - may deny a body part is yours or neglect it

Answer 27

1)aka contralateral neglect 2) damage to the right parietal association cortex (nondominant) -pts will be unaware of objects and events in the left half of his/her surrounds 3) Milder forms: -tendency to ignore things on the left side of the patients surroundings 4) Extreme cases -don’t even recognize the left side of his or her won body (ASOMATOGNOSIA) -ex: ignore left side when dressing 5) other symptoms: -losing the ability to function successfully within spatial surroundings -ex:unable to describe his/her route on the way home from work -unable to manipulate objects in space (contraction always apraxia) Ex: legos

Answer 28

1) Rhythm and feeling into speech - the way one says words - interpreting the emotional tone of the speech of another person 2) Lesion - cannot sing

Answer 29

Comprehending voice inflections (pitch/tone)

Answer 30

Right: - creative (mostly) - can-simple quantitative functions (summing small integers) - can understand simple language Left: - Language - Verbal - Analytical - quantitative - Linear (mostly)

Answer 31

1) Inability to acknowledge disease in oneself 2) ONLY RIGHT brain stroke-insular cortex and S1 and S2 + motor cortex= L side paralysis - pts tend to have anosognosia - Right side S1, S2 and insular cortex=centers for integration of body awareness 3) Left brain stroke-same area=no anosognosia - have issues with social interaction and personal decisions

Answer 32

Centers for integration of body awareness

Answer 33

Larger in females than males

Answer 34

AGENESIS OF CORPUS CALLOSUM - doesn’t develop at all - doesn’t hinder person much

Answer 35

-underdeveloped corpus callosum

Answer 36

- Smooth brain - no gyri or sulci developed - vary degrees of severity - live 1-2 years at most - caused by: genetic or viral infection during pregnancy

Answer 37

1) Each eye talks to both visual cortices | 2) Visual fields are lateralized, not eyes

Answer 38

Aka Wade Test 1) Inject a barbiturate (drug-shuts down activity) into R or L internal carotid Artery - determines which hemisphere is dominant for speech function - avoids neurosurgical procedures that might destroy language ability 2) Pt asked to count backwards will being injected - Hemisphere dominant for speech is affected= pt stops speaking and does not respond to a command to a command to continue 3) Test revealed that: - 96% of Right handed people are L brain dominant for speech - 70% of L handed people are L brain dominant for speech - 15% of L handed people control of speech in both hemispheres (injection didn’t supress speech fxn) - suppressing L hemisphere produces brief depression feeling - suppressing R hemisphere produces brief feeling of euphoria (buzz) - Functions related to MOOD may be lateralized in brain - Smage w/ R hemisphere-pathological indifference to their disability

Answer 39

1) Epileptics - provided hemisphere function - prevent seizures from spreading from one side of the brain to other=cut the corpus callosum and anterior commisure - each hemisphere can function independently - R-generally mute and cannot communicate about its experience verbally ; can do many things of L - Sensory analysis, memory, learning, and calculation performed by each hemisphere (R limited) 2) Split Brain patients - function normally - both hemispheres receive information from the world bc of the crossing pattern of visual input

Answer 40

1) Shown apple in right visual field - projects only to left hemisphere visual cortex - sees object 2) Shown apple in L visual field - pt denies seeing anything - if brain doesn’t know why you did something, it will manufacture a reason yo will believe is true

Answer 41

- reconstruction of fragmented parts - assembling wrong=false memory (feels right) - ego edits memories to make us remember them how we want to remember them

Answer 42

1) like macrophages-phagocytic - predominant cells involved in CNS inflammation 2) secrete IL-1B, TNF-a, prostaglandins, and neurotoxic molecules (glutamate, oxygen radicals) - secondary cause of neuronal damage following trauma or stroke

Answer 43

targets microglial in the CNS | -leads to neuronal damage and dementia

Answer 44

1) AKA receptive or fluent aphasia 2) defect of the comprehension rather than expression of language 3) Cause: - occlusion of temporal and parietal M4 branches of the middle cerebral artery - hemorrhage/tumors into thalamus extending laterally and caudally to invade the subcortical white matter 5) Severe wernickes aphasia - unable to understand what is said to them - unable to read (Alexia) - unable to write (agraphia) - fluent paraphasic speech (can talk normally) - unintelligible bc of frequent errors of word choice or made-up words 7) less severe cases - paraphasias occur: - literal paraphasia (incorrect but similar sounding word), - verbal paraphasia (word seems appropriate to the patient but is incorrect) 8) Much less aware of the extent of their disability vs patients with Broca's 9) Damage to basal nuclei-> associated with language disorders similar to wernickes

Answer 45

Associated with language disorders similar to wernickes

Answer 46

1) Disorder of sensory perception - not a loss of primary sensation (touch, vision, hearing) - Loss of the ability to interpret the sensation 2) only one sensory modality 3) difficulty in recognizing complex sensory stimuli 4) Forebrain lesion may cause variety

Answer 47

Inability to recognize a familiar object by sight

Answer 48

inability to recognize a common objects such as a coin, pencil, or key using sense of touch alone (tactile agnosia, asterognosis)

Answer 49

deficits to sense of smell

Answer 50

Deficit to sense of taste

Answer 51

Inability to recognize colors

Answer 52

- Involved in memory (declarative) - bilateral-in temporal lobes - strong connection with S2 (along with amygdala)

Answer 53

- responsible for base emotion (rage, anger, sexual) - limbic system - emotion valence driven by Amygdala - temporal lobe - strong connection with S2 (along with hippocampus)

Answer 54

1) NOt wired for written language | - only hearing and speaking language

Answer 55

Melding of 2 languages - 2 come together to 1 - basic grammatical structure

Answer 56

1) new language with grammatical complexity - arose from pidgin - comes from children

Answer 57

1) strong connection with Vision, language, and auditory areas 2) working with numbers - quantitative ability 3) interpretation of symbols (letters)

Answer 58

1) allows wercicke's and brocas to communicate - conduction aphasia - dominant hemisphere (L)

Answer 59

1) Anoia | - trouble remember proper names

Answer 60

Selfwareness

Answer 61

1) Doral Lateral prefrontal cortex | - working memory (temporary)

Answer 62

1) Left - language - verbal - analytical - quantitative - linear (mostly) 2) RIght - creative (mostly)

Answer 63

1) different parts of the cortex 2) Japanese language - Katakana-phoentic based - kanji -ideogram based

Answer 64

cannot comprehend written language

Answer 65

1) may be problem with angular gyrus 2) can read ideogram base language much better than phonetic based language 3) Intelligence is not altered

Answer 66

atypical modality crossing -taste something-hear sounds or see something that causes them to experience colors

Answer 67

MIII=deep in cingulate gyrus Completely mute - no emotion affect - sit still (not paralyzed) - just sits and stares When they come out: - will remember everything - from their perspective they were aware, just did not feel like doing anything

Answer 68

1) Integrates with limbic system 2) appropriate emotional response - emotion meets behavior (filter) 3) impulse - EtOH suppresses impulse control 4) Social interaction 5) project oneself into future 6) Lesion: - delusions, schizophrenia, paranoid

Answer 69

Anterior Cingulate gyrus Dorsal Lateral Prefrontal cortex (middle frontal gyrus) regulates attention and inattention

Answer 70

Ventromedial Area 1) Damage - reasoning and decision making in personal or social decisions

Answer 71

Dorsal Lateral Prefrontal Cortex -middle frontal gyrus Damage - impairment w/abstract reasoning and problem solving - attention issues - working memory

Answer 72

Frontal Eye field

Answer 73

1) Differs from one area to another in ways they are related to function 2) Heterotypical granular cortex - found in primary sensory cortex - layer 4-major input layer is thick - layer 5-major projection layer is narrow and indistinct 3) Heterotypical agranular cortex - found in primary motor cortex - layer 4- major input layer-invisible - layer 5-major projection layer-thick, merges w/Layer 2 4) Homotypical cortex - all 6 layers w/equal thickness - found in areas of the neocortex

Answer 74

Higher intellectual functions 4 functional categories 1) Sensory -except olfaction -receive thalamocortical (thalamus to cortex) fibers from diencephalic(thalamus + hypothalamus) relay nuclei related to each modality A) Primary somatosensory cortex (areas 1,2,3) -receive projections from ventral posterior (pain and temp) complex of thalamus -projects to area 5 (sensory association) B) Primary visual Cortex (Area 17) -receive projections from lateral geniculate nucleus -projects to 18 and 19 C) Primary Auditory Cortex (41 and 42) -receives projections from medial geniculate nucleus -projects to 22 2) Unimodal Association cortices: - adjacent to each primary sensory area 1) Visual Unimodal Association cortices (18, 19, 20, 21, 37) 2) Somatosensory Association cortex (area 5) 3) Auditory association cortex (area 22) 3) Motor 4) Multimodal Association cortex: - receives info from several sensory modalities and creates a wholistic picture of surroundings - important for comunicating using language, long range plans, imagine and invention

Answer 75

1) Controls Language 2) Majority-Left cerebral dominance - lesions 95% of cases 3) all right handed invidious and 1/2 of left handed: - L dominant

Answer 76

1) Disturbance of the compression and formulation of language - not a disorder of hearing, vision, or motor control - can affect verbal and nonverbal language 2) some language in Nondominate parietal lobe - lesion - difficulty understanding the PROSODY (voice inflections, emotional content that may alter the meaning of spoken sentence)

Answer 77

1) least common type of aphasia 2) Interuption of the Arcuate Fasciculus which allows wernickes and brocas to communicate 3) comprehension- normal expression-fluent -BUT THE patient has difficulty translating what someone has said to them in an appropriate reply

Answer 78

1) Occlusion of the left internal carotid artery or most proximal portion of middle cerebral artery (M1) produces damage that messes with both Brocas and wernickes area 2) Loss of language completely

Answer 79

1) Phineas gage - railroad worker - struck by rod beneath L eye and exited through the top of his head - destroying most of prefrontal cortex=CHANGING PERSONALITY Symptoms: w/bilateral damage to prefrontal cortex 1) Highly distractible or lack of consistency of purpose 2) Lack of foresight - can't anticipate or predict future events on basis of past or present conditions 3) Unusually stubborn - given advice-> disagree 4) lack ambition 5) Lack sense of responsibility 6) lack sense of social porpriety

Answer 80

1) Virus replicates in muscle tissue 2) Then transported retrograde - to cell bodies of neurons 3) Virus replicates in cel bodies - taken up by the terminals of adjacent cells - spreading infection through CNS - behavioral changes associated 4) Virus travels anterograde to salivary glands and shed virus in saliva

Answer 81

1) Tetanus toxin transported retrogradely - Axons (sites of infection)-> neuronal cell bodies - taken up by terminals of adjacent cells 2) Toxin is diluted as it passes cell to cell - can still produce neurological deficit

Answer 82

1) AKA orthograde 2) Cell body to terminals 3) Can be classified as Fast transport (100-400mm/day) -based on action of protein KINESIN= ATPase->moves macromolecule-containing vesicles and mitochondria along microtubules Slow transport(~1mm/day) - carries Structural and metabolic components - less understood

Answer 83

1) Terminals to Cell bodies 2) Driven by dynein 3) ONLY FAST NO SLOW 4) Allows neurons to respond to molecules - Ex: Growth factor taken up near axon terminal by PINOCYTOSIS OR RECEPTOR MEDIATED endocytosis 5) Also function in recycling of components of axon terminal

Answer 84

Enzyme horseradish peroxidase or fluorescent substance - injected into axon terminals - transported RETROGRADE (toward cell bodies)

Answer 85

Radioactively labeled amino acids or HRP - conjugated to WGA-HRP - injected into cell bodies - TRANSPORTED ANTEROGRADE

Answer 86

Anterograde (wallerian) degeneration | -can be seen with SILVER NITRATE STAIN

Answer 87

Results in CHROMATOLYSIS - changes in cell body; - cell body swells - nucleus->eccentric position - Nissl substance disperses

Answer 88

1) Nociceptors - Noxious (painful) stimuli 2) Thermorecptors - temperature changs in skin and viscera Both mediate pain -most common complaint in clinical medicine

Answer 89

1) 2 morphological categories: - electrical (electronic) - chemical-unidirectional; vast majority in mammalian CNS 2) Neurological diseases may alter the function of synapses

Answer 90

1) Parkinson Disesae 2) Bipolar Disorder 3) Alzheimer Disease 4) Myasthenia gravis

Answer 91

1) Disorder of NT metabolism 2) Affects dopamine-synthesizing neurons in the SUBSTANTIA NIGRA (area of brainstem) 3) Symptoms due to loss of Dopamine - Tremor - inablity to properly control movement 4) Therapy/tx: - L-dopa Supplements-> increases dopamine synthesisn but loses effectiveness overtime - Carbidopa-> ihhibits L-aromatic amino acid decarboxylase-> can't cross BBB-> decreases metabolism of L-dopa in peripheral thus more L-dopa available in CNS for dopamine synthesis - used with L-Dopa

Answer 92

1) Disorder of NT metabolism 2) affects several million American 3) Caused by imalances in the PHOSPHATIDYLINOSITOL (PI)-linked NT systems 4) Increase in PI turnover- triggered by Ach, Serotonin, NE and histamine receptors subcategories 5) Pathological imbalance of PI turnover may result in mood changes 6)TX: LITHIUM CARBONATE -stabliizes PI turnover, thus stabilizing mood

Answer 93

1) Disorder of NT metabolism 2) Affecs more than 1 million Americans 3) Definitive diagnosis only made postmortem by microscopic exam of brain tissue 4) Characterized by: - degeneration of neurons in basal forebrain nuclei - loss of synapses in the cerebral cortex and hippocampus - presence of neurofibrillary tangles and senile plaques 5) Terminals from Cholinergic (Ach-releasing) cells in basal forebrain nuclei to cortical cells are lost 6) Activity of Choline acetyltransferase (enzyme responsible for Ach synthesis) in cortex and hippocampus is extremely LOW 7) Other NT sysmtes affected - especially neuropeptides

Answer 94

1) Disorder of NT metabolism 2) Involves patients immune system protein antibodies to Nicotinic Ach receptors - ligand gated channel - found at synapse between primary motor neurons and skeletal muscle fibers 3) binding of antibodies to receptor results in: - destruction of neuromuscular junctions which causes muscle weakness

Answer 95

Type of GLIAL CELL 1) Protoplasmic astrocytes - located in gray matter - differ in shape 2) Fibrous astrocytes: - located in white matter - greater content of intermediate filaments 3) BOTH CAN BE A SOURCE OF TUMORS-astrocytomas 4) Tight junctions between astrocyte end feed reinforce BBB 5) Can be stained by GFAP 6) can breakdown glutamine to glutamate 7) Proliferation and/or hypertrophy of astrocytes fill in spaces of debris resulting from destruction of cells in CNS injury

Answer 96

1) arise from cells that make up the structure of the Brian, spinal cord, and its coverings

Answer 97

``` 1) location: adult- cerebrum children- cerebrum, cerebellum, Brain stem 2) most frequently encountered glial cell tumor 3) 4 types Grade I Astrocytoma Grade II Astrocytomas Grade III Astrocytoma Grade 4 astrocytoma -1&2 are slow growing astrocystomas ```

Answer 98

- uncommon tumor - grows slowly - usually arise from fibrillary astrocytes in white matter - occasionally protoplasmic astrocytes - may form tumors which contain fluid-filled cysts

Answer 99

1) Prominent processes filled with glial filaments 2) infiltrate between myelinated axons in white matter 3) Increasingly cluster around neurons in cortical gray matter 4) Commonly encountered in ADULTS - may take years before symptoms appear 5) If recurs after surgery-more aggressive->higher grade tumor

Answer 100

1) Aka anaplastic Astrocytoma 2) Enlarge nuclei w/increased density of chromatin - mitotic figures - uniform nucleus lost appearance - increased blood vessel density - RAPID GROWING MALIGNANT tumors

Answer 101

1) AKA glioblastoma multiforme (GBM) - highy malignant tumors 2) Spindled shape; - elongated nuclei - mitotic figures 3) can invade leptomeninges (arachnoid and Pia) 4) spread to contralateral hemispheres via corpus callosum 5) Complex neovascular structures and sharp borders between living and dead tumor tissue are common intrinsic features 6) "High grade" tumor is most common astrocytoma in: - middled aged and elderly adults 7) Survival time-only weeks

Answer 102

1) White Matter- Myelinate axons Gray matter- neuron "satellite" cells 2)OLIGODENDROGLIOMAS -slow growing tumor -adults=cerebrum -dark round concentric nuclei, w/clear cytoplasm (fried egg in egg white) -tumor cells form sheets 3) Located in lobes of brain (vs diencephalon or basal ganglia) 3) Hallmark- enlarge clusters around neurons (Satellitosis) and tumor cells beneath Pia mater

Answer 103

1) Arise from ependymal cells -line ventricles of the CNS 2) Seen most frequent in children <5 y.o 3) location: -Children/Adolescents-younger than 10 =4th ventricle -Adults= spinal cord-> cervical level** or in location of caudal equine 4) Less infiltrative than astrocytomas and more easily dissected 5) 5-6% of all glial neoplasms 6) most located in posterior cranial fossa (60-75%) 7) True Rosettes 8) Supratentorial lesion -hydrocephalus -seizure 9) Infratentorial Lesion -nausea and vomitting -headache -hydrocephalus -CN Signs

Answer 104

1) brain tumors that were Once regarded as arising from microglia 2) bone marrow derived=B-lymphocytes thymus derived cells=T lymphocytes 3) more frequent in patients who suffer from various states of acquired immunodeficiency (HIV or Immunodeficiency induced meds after organ transplant) -Epstein-Barr Virus may play a role 4) Tx successfully with medication or radiation (Some) 5) Reach CNS by breaching BBB -since Brain doesn't have any lymphatics

Answer 105

1) Cerebellum 2) Tumor that affects children - boys x2 3) Primitive Blue Cells(stem cells) 4) Neuroectodermal tumor - can differentiate 5) Most retain unstrained growth of embryonic cells w/o differentiation 6) Quickly spread along surface of brain and spinal cord - must be treated aggressively

Answer 106

1) Ex: Meningiioma and Schwannoma - covered by capsule that separate the tumor from surrounding brain - pushes against brain tissue vs extending fingerlike projections that invade white and grey matter

Answer 107

1) Arise from malignant cells that originate outside the nervous system 2) Lung Carncinoma - most common primary tumor to secondarily involve the brain 3) Breast Carcinoma - may spread to the dura or brain 4) Prostate Carcinoma - veins of BATSON's venous plexus-> spinal cord

Answer 108

1) Neurons are lost through disease or trauma are not replaced - EXCEPT olfactory epithelium and hippocampus 2) If axons are damaged but cell bodies remain intact: - regeneration and return of function can occur in some circumstances 3) Axonal regeneration: Best chance - periopheral nerve is compressed or crushed BUT NOT SEVERED

Answer 109

consists of: - 2 neurons - 1 synapse

Answer 110

1) Monosynaptic reflex arc - 2 neurons - 1 synapse 2) Input-> Sensory Fibers-> motor neuron in spinal cord - axon from motor neuron conducts a signal from the spinal cord to the appropriate skeletal muscle=contracts 3) Involuntary Reflex 4) Ex: Tendon reflex test

Answer 111

1) When trying to fine/localize a lesion: - CN signs are more helpful (Better localizing sign) than long-tract signs in trying to find the lesion 2) Deficits (motor or sensory) located on the same side of the head head and body signify lesions in the cerebral hemispheres 3) Crossed or alternating deficits - on one side of the head and on the opposite side of the body indicates a lesion in the brainstem (contralateral to brainstem 4) Deficits of only the body - lesion in the spinal cord

Answer 112

Localizes only to one cerebral hemisphere or to one side of the side of the brainstem Clinical exam does not tell us which region of the brain is injured (internal capusule, midbrain, pons,, medulla) or whether to lesions is in the upper portions of the cervical spinal cord

Answer 113

1) localized to the midbrain | - damaged the oculomotor nerve and the corticospinal fibers supplying the UE as they transverse this area

Answer 114

1) Signs - different from the normal structure/function - observed and evaluated by physician 2) Symptoms - different from the normal structure/funciton - experienced by the patient

Answer 115

1) Computed Tomography 2) X-ray imaging that measure tissue density - higher the atomic number the greater ability to attenuate or stop the x-rays 3) Use Hounsfield Units (HU) - aka CT numbers 4) Provides fast and accurate method of detecting RECETN SUBARACHNOID HEMORRHAGES - subarachnoid hemorrhage appears hyper dense (white) - subarachnoid space and cisterns appear hypodense (black) 5) Neoplams - areas of inflammation - can be detected w/enhanced CT bc contrast agents leak from vessels into cellular spaces

Answer 116

1) Area 5 and 7 2) strong connection to contralateral areas 5 and 7 - hemispheres communicate about motor coordination 3) Receives sensory input from the post central gyrus (1,2,3)=feedback mechanism for fine motor adjustments - 5-> input from somatosensory and vestibular system; active when reaching for objects - 7->input from visual cortex related to objects in space (hand eye coordination) 4) Make up 1/3 of the corticospinal tracts - pyramidal fibers 5) Lesions: - can't use both hands in coordinated way to accomplish fine motor tasks

Answer 117

1) Premotor cortex 2) Supplementary motor cortex (M2) 3) M1 are 4 and 6

Answer 118

1) Can't propagate action potential 2) provide neurons w/structions support and maintain environment for neuron fxn 3) Type of Glial Cells - Astrocytes - oligodendrocytes - microglia

Answer 119

1) Gs coupled 2) Stimulates activity of adenylyl cyclase ATP-> cAMP 3) endogenous ligand for this receptor=catecholamine epinephrine

Answer 120

1) used clinically in CARDIOpulmonary resuscitation during cardiac asystole and to treat anaphylactic reactions

Answer 121

1) interferes with the binding of NE to postsynaptic 2) prescribed to manage: - agina pectoris - hypertension - congestive heart failure

Answer 122

1) NT 2) Regulates the sympathetic division of the ANS in the peripheral nervous system -binds to a- and b- adrenergic receptors 3) Greatest source of NE in mammalian CNS =locus ceruleus

Answer 123

1) AKA a-methyltyrosine AKA metyrosine 2) Competitive inhibitor of Tyrosine Hydroxylase 3) Pts who suffer symptoms from excess production of catecholamines from pheochromacytomas

Answer 124

1) derived from tyrosine pathway 2) includes: - epinephrine - norepinephrine - Dopamine

Answer 125

1) Plant Alkaloid 2) Earliest therapeutic agents for tx of hypertensive cardiovascular disease 3) may give Parkinson like symptoms 4) Inhibits Dopamine and Norepinephrine 5) Rarely used today to treat hypertension

Answer 126

1) A-methyldopa 2) effective antihypertensive drug during pregnancy 3) reduces the accumulation of dopamine and norepinephrine in synaptic vesicles

Answer 127

1) Reserpine Like 2) Causes: - excessive reduced heart rate, nasal congestion, and orthostatic hypotension

Answer 128

1) Reserpine like 2) present in many herbal preparations and beverages - thought to be aphrodisiac 3) promotes erectile dysfunction

Answer 129

1) Cocaine and Amphetamines 2) enhance motor performance, relieve fatigue, and enhance synaptic concentrations of monoamines (tyrosine pathway) 3) Cocaine - inhibit membrane monoamine transporters - ruduces reabsorption of monoamines out of synaptic cleft 4) AMphetamine - inhibit MAO-A (Periphery) and MAO-B (Braine)

Answer 130

``` 1) AKA Parnate and (Phenelzine aka Nardil) 2) nonselective inhibits -block both MAO-A and MAO-B 3) treats major depressive disorders 4) Frequent side effects ```

Answer 131

1) AKA L-deprenyl, Eldepryl 2) selective inhibitor of MAO-B 3) Blocks mitochondrial degradation of Dopamine in CNS 4) management of Parkinson's

Answer 132

1) When CSF accumulates in ventricular spaces or around the brain - reabsorption failure - overproduction - obstruction of movement 2) usually caused by: - obstruction of CSF flow=enlargement of the ventricular space 3) Characterized by: - Increased in CSF volume - enlargement of one or more ventricles - increase in CSF pressure

Answer 133

1) Gial scarring (Gliosis) due to infection 2) Development defects of forebrain 3) rupture of amnionic sac in utero 4) forking of aqueduct

Answer 134

1) obstruction within ventricular system or subarachnoid space 2) Common INTRAVENTRICULAR SITES: - interventricular foramen - cerebral aqueduct - caudal portions of 4th ventricle - foramen of 4th ventricle 3) Common Extraventricular sites in subarachnoid space: - base of brain - tentorium cerebelli - tentorial notch - over the convexity of hemispheres - SSS

Answer 135

May be caused by: 1) tumor in midbrain - pineoblastoma or meningioma 2) occluded by cellular debris following: - intraventricular hemorrhage - bacterial or fungal infections - ependymal proliferation due to viral infections of CNS (mumps) ``` Major sequela (consequence)= Triventricular hydrocephalus -enlargement of 3rd and both lateral ventricles ``` Obstruction of foramina of Magendine and Lushka -enlargement of all parts of ventricular system

Answer 136

1) Movement of CSF through subarachnoid space into venous system is partially or totally blocked 2) Caused by: - Agenesis (congenital absence) of arachnoid villus - Villi partially blocked by RBC following subarachnoid hemorrhage or major CNS infection (leptomeningitis) and subsequent immune response - overproduction of CSF in patients w/papilloma of choroid plexus 3) will have: - High levels of proteins in CSF->500mg/dL (CNS tumors or inflammation) - High CSF pressure 4) RESULTS: - enlargement of all parts of ventricular system

Answer 137

1) Not true hydrocephalus - but atrophy of the brain resulting in ventricles that larger due to loss of white matter 2) No increase in intracranial pressure 3) no neurological deficits other than those related to brain atrophy

Answer 138

1) AKA pseudotumor cerebri 2) Most commonly seen in: - obese women of child bearing age - chronic renal failure patients 2) Could be related to VIT A toxicity 3) Increased in Intracranial pressure (>25 cm H2O) - w/little evidence of pressure increase on CT or MRI scans 4) Sympotoms: - headaches - visual deficits (up to blindness) due to papilledema (swelling of optic disc)

Answer 139

1) Unclear Cause 2) CSF elevated periodically=Elevated Intracranial Pressure periodically - may return to high-normal level - effects of increased pressure remain 3) usually elderly patients affected 4) Sympotoms: - diagnostic triad of urinary problems (frequency, urgency, incontience) - impaired Gait-steps on curb - dementia 5) Can look like a degenerate disease - Parkinsons - ALzheimers

Answer 140

1) Caused by: - hemorrhage into the brain (cerebral hemorrhage) the subsequently ruptures into ventricular space - Rupture of an intracranial aneurysm (3rd and 4th ventricle) - Severe head trauma 2) Blood in ventricles seen on CT - especially acute blood - white appearance

Answer 141

1) rare, <1% of intracranial tumors 2) most common b/w: birth- 10 y.o 3) Located: - 4th ventricle (50-60%) - lateral ventricles ``` 3)2 types choroid plexus papillomas -benign -more frequent -surgical removal ``` choroid plexus carcinomas - malignant - rare - 1) chemotherapy 2) Surgery 3) chemotherapy + radiation

Answer 142

1) CSF high conc: - chloride - magnesium - sodium 2) Similar conc to Blood plasma - creatinine 3) lower conc - potassium - calcium - glucose - proteins - albumin - uric acid

Answer 143

1) clear and colorless 2) very little protein (15-45 mg/dL) - little immunoglobulin - 1-5 leukocytes per millilter 3) Changes from normal values useful in diagnosis - indicative of pathological state

Answer 144

1) collect a sample of CSF for analysis and two measure CSF pressure 2) Needle inserted b/w third and fourth (or fourth and fifth) lumbar vertebrae into dural sac -spinal pressure measured -few milliliters of fluid withdrawn 3)-sample that is removed is quickly replaced Since average volume of CSF in adults is 120 mL/day -rate of production is 450-500 mL/day

Answer 145

1) 3 test tube test: determines where blood is from -subarachniod hemorrhage -traumatic tap (damage to vessel during procedure) 2) 3 successive tubes of CSF drawn -first=blood -2nd=little or non -3rd=none RESULTS In traumatic tap 3)) if all 3 tubes contain bloody CSF that is also xanthochromic =SUBARACHNOID HEMORRHAGE

Answer 146

1) neutrophils predominate - 1000-20,000/mL 2) Cloudy CSF

Answer 147

1) Lymphocytes | - 200-300 cells/mL

Answer 148

1) Lymphocytes - less than 50 cells/mL 2) ALSO need: - changes in the Immunoglobulin G content of CSF - slight increase in mononuclear cells

Answer 149

1) AKA pachymeninx 2) thick outer layer 3) does not contour brain 4) elongated fibroblasts and alot of collagen fibrils 5) Periosteal/endosteal - outer layer - attached to inner surface of the skull (periosteum) - Strong attachment along suture lines and cranial base - ends at foramen magnum of occipital bone - Fibroblast larger and less elongated 6) Meningeal - inner layer - Fibroblasts flattened, elongated, nuclei smaller, and cytoplasm darker 7) Dura Border cell layer - innermost part - Fibroblasts flattened, sinuous processes - no collagen present - attached to arachnoid membrane by: cell junctions-desmosomes and gap junctions

Answer 150

1) Supratentorial compartment - superior to tentorium cerebelli - bilateral (r and L)-seperated by Falx cerebri 2) Infratentorial compartment - single - inferior to tentorium cerebelli

Answer 151

1) intracranial event (hemorrhage, rapid tumor growth, traumatic brain injury) causes: - increase in intracranial pressure-> forcing brain over edge of dural reflection

Answer 152

1) Subfalcine or cingulate herniation 2) Central (transtentorial) herniation 3) Uncal herniation

Answer 153

1) Supratentorial Compartment 2) AKA cingulate herniation 3) lesion in one cerebral hemisphere expands toward midline - forces cingulate gyrus under Falx cerebri into opposite hemisphere 4) Deficits: - oclusion of anterior cerebral artery

Answer 154

1) Supratentorial Compartment 2) AKA transtentorial herniation 3) diencephalon is forced downward through tentorial incisure or notch 4) Neurologic emergency - 90% of patients-serious disability or death

Answer 155

1) Supratentorial Compartment 2) rapidly expanding lesion - usually hematoma - forces uncus over tentorium cerebelli - damages midbrain 3) common deficits: - decreased level of consciousness - dilation of the pupil and loss of eye movement reflecting damage to ipsilateral oculomotor nerve - Contralateral hemiplegia

Answer 156

1) Upward cerebellar herniation | 2) Tonsilar herniation

Answer 157

1) Infrantentorial 2) mass or pressure increases in posterior cranial fossa forces cerebellum upward through tentorial incisure 3) Damage to midbrain

Answer 158

1) infratentorial 2) tonsils of cerebellum are forced downward into/through foramen magnum - pressure on medulla - damage respiratory centers 3) DEATH

Answer 159

1) Usually Single tumor - benign - slow growing 2) Primary intracranial tumors but not primary tumors of the brain 3) Women 30/40-60 most common 3) Arise from Arachnoid Cap cells - arachniod cells associated with arachnoid vili 4) most found in the cranial Cavity (90%) - spinal cord (9%) - ectoptic meningiomas (1%)-outside CNS 5) located: in order of occurence - parasagittal (parasagittal meningioma) - Convexity (Convexity meningioma)-designed by lobe - Sphenoid ridge (Sphenoid Ridge meningioma) - Tuberculum Sellae or suprasellar 6) also found at: - attached to falx cerebri (falcine meningioma) - attached to tentorium cerebelli (Tentorial Meningoma) 3 types: 1) Meningotheliomatous (syncytial) - polygon shaped w/large central nucleus - arranged in sheets or whorls 2) Transitional - b/w syncytial and fibrous appearance - whorl formation - psomma body - small blood vessel 3) Fibroblastic - long spindle shaped cells w/elongated nuclei - whorl formation - psomma body

Answer 160

1) blood the strips the dura from the skull or opens the dura border cell layer 2) most common cause: - Head injury with or without skull fracture

Answer 161

1) Head injury 2) Periosteal dura from skull to form EPIDURAL Space 3) Damges middle and accessory meningeal arteries 4) Blood collects to form EPIDURAL/extradural HEMATOMA 5) Increased Intracranial Pressure 5) Lesions: -lenticular shaped -appear short and wide 6) Neurological Deficits: in order of occurence -headache -confusion and disorientation -Lethargy -state of unresponsiveness 7) "Tak and Die" -initially unconscious -lucid interval (wide awake and talking) -rapidly detoriatee =DEATH

Answer 162

1) Head injury 2) bleeding into meninges b/w dura and arachnoid= Subdural Space 3) Tears Bridging vein as they pass through subarachnoid space->dural venous sinus - Veenous blood 3) Results in Subdural Hematoma or DURAL BORDER hematoma - splits open dural border cell layer

Answer 163

1) usually arterial blood into subarachnoid space 2) most common cause: -trauma -large veins 3) most common cause of non-traumatic: -rupture of intracranial aneurysm -40-65 yrs old 4) 1/3 die before or soon after admission to doctor 1/3 have permanent and significant disability (cognitive and motor) 1/3 recover with minimal neurological affects 5) The occurrence of subarachnoid hemorrhage signaled: -headache as "explosive and awful" 6) Diagnostic; -bloody CSF via lumbar puncture -CT exam

Answer 164

1) Baterial or viral origin

Answer 165

1) located: -subarachnoid space -involves leptomeninges (pia and arachnoid) 2) Causes: -trauma -septecemia -metastasis from another site of infection in body 3) Classification -acute -subacute -depends on how reply disease progresses 4) Most Common Causitive Agents: -Streptococcus Pneumoniae -Neisseria Meningitides (75%) 5) Signs and symptoms: Acute: (days) -elevated temp -alternating chills and feveer -headache -depressed level of consciousness -ICP -hydrocephalus -cranial nerve palsies -nausea and vommiting -neck pain -nuchal rigidity -petechial rash -photosensitivity -postive kernig and Brudzinki sign w/ increased CSF pressure, cloudy CSF w/many WBC, Increased protein and bacteria=diagnositic Subacute: (weeks rather than days) - may be due to mycotic infections - onset is slow - headache - fever - irritablity - wakefulness at night 6) Prognosis: -excellent (90%) cure rate with early diagnosis and treatment -recover In weeks -can be lethal if not treated 70 Tx: -antibiotics

Answer 166

1) Commonly seen in younger patients (<25 yrs) 2) no antiviral meds available - suportive with focus on fever pian 3) caused by range of viral agents - enteroviruses - mumps - Epstein-Barr - herpes - Varicella-zoster (chicken pox) - measles - influenza 4) Pt becomes ill over a period of days and experiences: - fever - headaches of increasing intensity - nuchal rigidity - photosensitivy - somnolence (sleepy) - nasua and vomitting - confusion - altered level of consciousness ``` Less often: more serious sings and symptoms: -seizure -rigidity -cranial nerve palsies 5) Lumbar puncture -clear or cloudy CSF -hihg 25-500mm lymphocyte count -slightly elevated lymphocyte 6) prognosis -after 1 to 2 weeks the signs and symptoms moderate -pt recovers without permanent deficits not fatal ```

Answer 167

1) seen in patients w/immune deficiency such as aids

Answer 168

1) due to infection with amoebae | - contracted from freshwater sources

Answer 169

1) all cases of meningitis in which no bacterial infection can be demonstrated 2) usually due to viruses but can be due to bacterial infection that has already been partially treated -disappearance of bacteria from meninges OR -infection in a space to the meninges (sinusitis)=caused by endocarditis

Answer 170

1) 2x more likely in women 2) Benign Tumor 3) Acoustic Neuroma

Answer 171

1) Cobalamin 2) essential dietary nutrient found in meats 3) causes b12 deficiency: - perniscious (unexplained) anemia (major) - strick vegetarian diet - inability to reabsorb vitamin - autoimmune diseases 4) common in the US-elderly 5) Symptoms: - serious anemia - nerve damgae - spinal cord degeneration - MYELIN DAMAGE - paresthesia - seizuires - developmental regression - Dementia 6) Signs/Syndromes: Lhermitte's sign - AKA Babar Chair Phenomenon - classic finding's in MS - electrical sensation that runs down the back and into limbs - elicited by bending head forward

Answer 172

1) AKA beriberi 2) breakdown carbohydrates and decreases utilization of amino acids -CNS depends on for energy -if defective, the body will utilize ketone bodies A) beta-hydroxybutrate (main) -acetoacetic acid -Acetone (Fruity Breath) 3) Symptoms - tingling/buring sensation in extremities - motor issues (ataxia) - leg weakness - pain - vomitting - Polyneuritis=myelin damage in PNS and CNS ``` 4) Syndromes; Korsakoff Syndrome -chronic/irreversible -short term memory loss -alocholic dimentia -coomfabulation ``` Wernickee Encephalopathy - acute/reversible - ataxis - opthalmoparesis - confusion - motor/memory loss