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209 Cards in this Set
- Front
- Back
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Central Nervous System
(CNS) |
Brain and Spinal Cord
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Peripheral Nervous System
(PNS) |
Peripheral Nerves and Ganglia
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Afferent (sensory)
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To CNS from Peripheral receptors
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Efferent (motor)
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From CNS to muscles, organs, glands
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Sympathetic Nervous System (SNS)
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energy consuming mechanisms
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Parasympathetic Nervous System (PSNS)
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energy conserving mechanisms
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Nuclei
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cell bodies within CNS
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ganglion
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cell bodies within PNS
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pre-ganglionic neuron
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neurons from CNS make synaptic connections within ganglionic neuron interface
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post-ganglionic neuron
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located in ganglionic interface, axons travel to connect with muscles/glands
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Tract
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CNS version of a nerve; bundle of neuron axons in CNS
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Nerve
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bundle of neuron axons in PNS
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Autonomic Nervous System:
(SNS) |
"fight or flight"; norepinephrine
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Adrenergic receptor subtypes:
Alpha 1 |
increases: vasoconstriction, blood pressure/ flow speed, hepatic gluconeogenesis- blood sugar levels
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Beta 1
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increases: heart rate and force
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Alpha 2
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decreases: sympathetic output
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beta 2
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increases: broncho dialation, digestion
decreases: gi motility, insulin production> sugar |
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Autonomic Nervous System:
(PSNS) |
"rest and digest'; acetylcholine
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Cholinergic receptors
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decreases: heart rate/force of contraction/blood pressure
increases: bronchial constriction, gi activity/secreations, bladder contractions/urination |
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agonist
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activates receptor; mimicks hormone/NTS
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antagonist
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blocks receptor activation by hormone/NTS
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Nervous System Cell types:
neuroglia (glial cells) |
non-nervous tissue type, majority of cells in NS. protection, support, barriers, phagocytise, produces insulating materials/CSF, increases "interconnectivity", help repair, replace, regenerate
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Neuroglia cells of CNS;
Astrocytes |
(fibrous and protoplasmic)forms highly selective barrier- blood-brain barrier (BBB); neural networking
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Oligodentrocytes (CNS)
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produces mylein sheath around axons
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ependymocytes
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(ependymal cells)
associated with choroid plexus (brain)- produces cerebrospinal fluid (CSF) |
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microglia (brain macrophages)
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protect brain from infection/foreign substances (embryonic) "reserve mesenchymal glia cells"
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Neuroglia cells of PNS:
neurolemmocytes (shwaan cells) |
forms myelin sheath; helping axonic regeneration of nerve cell damage- wallerian degeneration
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neurons (nerve cells)
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from neuroblasts; make and release NTS, highly excitable, conductive, message-propagating cells
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neuron parts:
cell body |
contains nissl bodies, site for NTS production, anarobic
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dendrites
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sensory receptor sites for incoming messages; carry currents toward cell body
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axons (spikes)
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terminates as end-knobs, which stores NTS & releases it when end-knob is depolarized; conducts impulses away from cell body
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neurolemma
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cell membrane
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axolemma (neurolemma)
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neurolemma of axon; permits action potentials
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dendrolemma (neurolemma)
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neurolemma of dendrite; permits graded potentials
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myelin sheath
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phospholipid membrane wrapping around regions of the neuron; damage/repair, speeds up conduction by saltatory conduction
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neuromere (like sarcomere)
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"conducting units" of neuron
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neurofil nodes- Nodes of Ranvier
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unmyelinated spaces- associated with saltatory conduction
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lipofuscin
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yellowish "aging pigment"- aging of neurons; final end product
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Embryonic Nerve Growth Factors/Hormones
(ENGH) |
development of PNS, SNS, PSNS; increases hypertrophy, axonic growth/regeneration, ACH production & maintain homeostasis
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Class. of neurons
unipolar |
myelinated, sensory
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bipolar
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short distances; unmyelinated, sensory, central cell body with small axons
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multipolar
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myelinated motor- always efferent
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pyramidal cells
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primary motor cortex, in cerebrum- motor control of voluntary muscles
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extrapyramidal cells
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basil ganglia (motor neuron)- unconscious motor control
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purkinje cells
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motor cells of cerebellum
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horizontal cells
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" " that link purkinje cells
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interneurons (associative)
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btw other neurons
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regions of neurons;
pre-synaptic neuron |
release NTS into synapse (sending the signal)
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post-synaptic
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axoaxonal (neuron), neuromuscular, neuroglandular transmission; releases agent to breakdown NTS (receiving signal)
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acetylcholinesterase
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breaks down acetylcholine- choline & acetic acid, back into pre-synatic vesicle
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monoamine oxidase (MAO) A & B
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breaks down: monoamine NTS-dopamine, serotonin, NE, epinephrine, histamines (CNS); amino acids- GABA, glycine, glutamate aspartate; neuropeptides- substance P, enkaphalins, galanin, neuropeptide Y
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nerve cell physiology:
resting membrane potential |
-70mV: cell membrane @ rest
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depolarization
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inside of cell becoming more + (-60mV to +30mV); sodium ions entering cell
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threshold
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action potential develops:
-60mV |
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hyperpolarization
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inside of cell becomes more -
-80 to -90mV (less sensitive) |
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hypopolarization
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inside of cell becoming less negative
up from -70mV (more sensitive); potassium ions out of cell |
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excitation
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process leading to depolarization, may/may not lead to action potential, closer to threshold
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inhibition
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leading to hyperpolarization- action potential more difficult
from -70 to -75/-80mV |
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communication:
graded potential |
depolarization as far as ions can travel locally; unmyelinated
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action potential
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depolarization- all or nothing path away; impulse across great distance; myelinated
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continuous conduction
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slower; unmyelinated- chronic pain pathways, post ganglionic sympathetic neurons
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saltatory conduction
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5-7x faster; myelinated neurons, "jumping message" btw nodes of ranvier
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neurotransmitter
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substance that inhibits or stimulates postsynaptic cell
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nitric oxide (NO)
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regulates production/release of NTS; action of NTS depends on its presense or absense
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carbon monoxide
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same as NO- abiltiy to regulate same/similar activity in body
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NTS mechanisms:
ionotrophic |
inducing ion (electrolyte) flow into/out of neurolemma
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metabotrophic
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inducing intracellular changes in proteins, amino acids, etc
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excitatory/inhibitory
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enhance or inhibit transmission of action potentials- allow/prohibit to take place
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cholinergic nerve fibers
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parasympathetic/somatic- production of Ach; neutralized by Ache; ionotrophic
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adrenergic nerve fibers
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sympathetic; monoamines- NE dopamine, serotonin histamines, epinephrine
CNS and PNS |
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Acetylcholine (Ach)
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Acetylcholinesterase (Ache); excites; association PNS, somatic responses, cholinergic, neuro...connections; ionotrophic
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Norepinephrine (NE)
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Monoamine Oxidase (MAO); both (E&I); increases: heart beat, blood pressure; greater alpha, lesser beta; metabotrophic
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Dopamine
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MAO; both; low- increased renal artery blood flow, medium- increased heart rate, high- increased blood pressure; nigrostriatal- decreased muscle spasms, tubuloinfundibular- decreased lactation, mesolimbic- increased psychosis/schizophrenia; metabotrophic
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epinephrine
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MAO; both; increased: heart beat, blood pressure, sugar levels due to stress; greater beta, lesser alpha; metabotrophic
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serotonin
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MAO; excites; increases: brain/mood activator, decreases: gut motility; mediates inflammation; metabotrophic
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histamine
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MAO; excites; increases: inflammatory response; metabotrophic
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Gamma Amino Butyric Acid (GABA)
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MAO; inhibits; increases hyperpolarization of cell membranes; ionotrophic
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Glycine
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MAO; inhibits; decreases spastic muscle action; ionotrophic
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Glutamic & aspartic acid
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MAO; excites; decreases threshold to hypopolarize membranes; ionotrophic
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enkaphalins (endorphins)
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MAO; inhibits; brain opiates; increaes pleasure, decreases pain reception; metabotrophic
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substance P
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MAO; excites; increases pain reception & alertness; metabotrophic
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galanin
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MAO; excites; increases desire for fats/fatty foods; metabotrophic
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neuropeptide Y
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MAO; excites; increases desire for carbs; metabotrophic
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Alcohol
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CNS depressant; dopamine, other catecholamines; lack of fine motor control, balance, equalibrium; cirrhosis of liver, pancreatitis, seizures, etc
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amphetamines
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CNS excitation; NE; mimicks NE, blocks reabsorption of NE, increases NE release, decreases MAO release
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caffeine
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CNS excitation; NE, dopamine, Ach; modulates cyclic neucleotides (AMP & GMP), brain activity, alertness, vasodialation/constriction, bronchodilator, increases heart rate/blood pressure, decreases alzheimer manifestation
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nicotine
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SNS & PNS- ganglionic blockade- depressant; NE, dopamine, Ach; low-decreases sympatheic outflow (tension/heart rate/blood pressure) high- increased anxiety, arteriosclerosis, heart damage
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cocaine
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CNS euphoric; serotonin, NE, dopamine; short-term euphoria, psychosis, cardiac arrhythmia & more
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marijuana (THC)
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CNS depressant; endorphins, Ach, dopamine; impairs balance/equalibrium, affects judgment, depth perception, impacts on memory/timing
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lysergic acid diethylamide (LSD)
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CNS excitation; serotonin; increases psychosis- visual/auditory hallucinations
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anti-psychotic (neuroleptics): chlorpromazine (thorazine)
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CNS inhibitor; dopamine, NE, histamines, serotonin, Ach; decreases agression, anxiety, increases sedative, parkinsonian effects, anti-histamine/cholinergic, hypotensive
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Anti-anxiety- sedatives, hypnotic, sleep inducers: (benzodiazepine- valium, librium, ativan, xanax; non-benzodiazepine- buspar, ambien)
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CNS inhibitor; decreases catecholamines; sedative, sleep inducive, reduces anxiety
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anti-depressant: SSRI (zoloft, paxil, prozac); NE/dopamine agonists (wellbutrin, zyban); tricyclic (elavil); MAO inhibitors (selegeline)
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CNS excitation; increases serotonin levels, NE, dopamine & other catecholamines
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anti-hypertensive (inderal); non-specific beta receptor blockers
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PNS: increases PSNS, decreases SNS; NE, Ach, dopamine, epinephrine; decreases role of NE, dopamine, epi; increases role of Ach; decreases heart rate, increases bronchial constriction/insulin release to decrease sugar levels
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analgesics; opiates (morphine, heroin)
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CNS inhibitors; increases endorphins; decreases pain & respiratory drive
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anti-cholinergic (atrophine)
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PSNS inhibitor/SNS enhancer; decrease Ach, increase catecholamine; blocks Ach receptors; increases catecholamine effects to increase heart rate/force/blood pressure
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cholinesterase inhibitors (DDT, organophosphates, insecticides)
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PSNS enhancers; increases Ach; increase bradycardia (decrease heart rate & force) & spasmodic muscle action
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Neuromuscular blocking: strychnine
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PSNS; amino acids; blocks glycine receptors- uncontrolled muscle spasms leads to death
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curare
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PSNS; Ach; muscle paralysis (used in surgery)
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botulism toxin
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PSNS; Ach; decreases Ach releases- muscle relaxant, increased respiratiory failure
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autoimmune neuromuscular blocking disease: myasthenia gravis syndrome
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PSNS; Ach; anti-Ach-antibodies block Ach receptors
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lamberton-eaton syndrome
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PSNS; Ach; anti-Ach-antibodies block Ach release
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meninges (protective covering)
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dura mater: outermost membrane (buffer), arachnoid layer: central membrane, CSF flow btw dura & pia; pia mater: innermost layer-direct contact with brain and spinal cord
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meningitis
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bacterial/virual/fungal/TB-fever, lethargy, stiff neck, purple spots; prognosis: full recovery, some possible residual damage (mental/nerve/tiisue)
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encephalitis (inflammation of brain)
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bacteria/virus/fungus/protzoan- may lead to damage or death, usually rapidly fatal
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ventricles (cavities of the brain)
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produces cerebral spinal fluid
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lateral ventricles (I & II)
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1 in each cerebrum; separated by septum pellucidum; drain CSF into 3rd ventricle by interventricular foramen (foramen of monro)
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3rd ventricle
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in diencephalon- drain CSF into 4th ventricle thru cerebral aqueducts (in midbrain)
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4th ventricle
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btw pons & cerebullum- empties into medulla oblongata- which narrows & becomes the spinal cord
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Blood-brain-barrier (BBB)
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astrocytes form highly selective barrier- controls stuff into/out brain; restricts passage
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Cerebrospinal Fluid
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formed in choroid plexus w/ependymal cells
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Two folds of choroid plexus: Fold 1
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roof of 3rd ventricle & thru foramen of monro to floor of lateral ventricle
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Fold 2
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in roof of 4th ventricle
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production of CSF
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ependymal cells in choroid plexus form tight junctions over capillaries; CSF secreated into ventricles
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function of CSF
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protection, support, transportation, coolant, diagnostic tool
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CSF pathophysiology
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hydrocephaly- "water on the brain'- accumulation of CSF in the brain- strangulation of brain stem- resp. paralysis/death
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spinal cord regions
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terminates L2 vertebra; medulla oblongata; PSN
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cervical
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C1-C8; 8 cervical nerves; innervates head/neck/arms; from pons/medulla
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thoracic
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T1-T12; autonomic (SN); 12 nerves; innervates chest/thoracic/abdominal
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lumbar
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L1-L5; autonomic (SN); 5 nerves;innervates pelvic
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cervical/thoracic enlargement
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nerves to shoulder girdle/arms (vestigal activity)
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lumbar enlargement
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nerves to pelvis/legs (vestigal)
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Caudae Equinae (horse tail)
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fanning out spinal nerves- terminal end of spinal cord @ L2- lower abdomen/extremities (SN L3-L5 & PSN sacral)
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Spinal cord matter:
white matter |
white myelinated axons; interior
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gray matter
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grey unmyelinated axons; surface/cortex
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spinal cord reflexes
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rapid, unconscious responses to changes in internal/external environment- maintains homeostasis
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spinal cord utilization:
posterior |
dorsal root/ganglion- afferent (sensory)
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anterior
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ventral root; efferent (motor)
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reflex arcs
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2 neurons (at least): receptor site-sensory-motor-effector site
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types of relex arcs:
divergence |
1 neuron to many others- coordinate complex resp. to unilateral stimuli
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convergence
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from many different neurons to 1
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reverberating (recurrent)
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linear sequence: a-b-c-d; neuron c sends back to a to start over
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examples:
alert cycle |
loop in reticular activating system
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pain response
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pain sensation continues to protect after damaged
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spatial/temporal summation:
(parallel after-discharge |
parallel nerves stimulating common output;impulses reach output @ different space/time creating burst "after-discharge"
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reflex arcs as diagnostic tool:
patellar reflex (knee-jerk) |
stretching quad muscle/tendon-contraction of muscle; L3-4
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achilles (ankle jerk)
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stretching gastrocnemius muscle/tendon- contraction of muscle & involuntary plantar flexion of foot
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positive babinski (stroking sole of foot)
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big toes extends with or w/out toes fanning out- in kids under 18 mo
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negative babinski (plantar relfex)
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past 18 mo; curling toes down when sole of foot is stroked
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bicep reflex
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stretch bicep brachii muscle/tendon- contraction of muscle- C5-6
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tricep reflex
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stretch tricep brachii muscle/tendon- contraction of muscle- C7
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abdominal reflex
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stroke side causes same side deviation of umbilicus toward stimulus- due to contraction of rectus abdominus
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cremasteric reflex
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temp regulator; superior medial thigh (males)- contraction/relaxation of cremasteric muscle of groin; distance of testes to body & force of ejaculation
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anal (vagal) reflex
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stroke around anus- contraction of external sphincter- S4-5
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3 divisions of brain
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prosencephalon (forebrain), mesencephalon (midbrain), rhombencephalon (hindbrain)
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procencephalon (forebain) contains:
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telencephalon & diencephalon
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telencephalon
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cerebrum, cerebral nuclei, limbic system, corpus collosum
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diencephalon
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thalamus, hypothalamus, pineal gland, mammilary bodies
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Rhombencephalon (hindbrain) contains:
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metencephalon & myelencephalon
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metencephalon
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cerebellum & pons
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myelencephalon
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medulla oblongata
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brain stem includes:
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parts of- diencephalon, mesencephalon, rhombencephalon
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forebrain (new brain):
telencephalon |
cerebrum- center of intellect, memory, languages, vision, senses, emotion and "human consciousness"
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Lobe #1: Frontal
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primary motor cortex- (precentral gyrus)- controls somatic motor neurons of brain stem/spinal cord
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frontal
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motor association area- (premotor cortex)- coordination of learned movements
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frontal cont...
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prefrontal cortex- integrates info from sensory assoc. areas to entire cortex; anxiety, frustration, tension of future events
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lobe #2: parietal
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primary sensory cortex- (post-central gyrus)- touch, pressure, pain, vibration, taste and temp. receptors; somato-sensory assoc. area
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parietal
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Broca's area- speech and communication, speech center
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parietal cont...
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wernickes' area- language and math
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lobe #3: temporal
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auditory stimuli- interpretation of sound
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temporal
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olfactory cortex- olfactory stimuli- smells and taste
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lobe #4: occipital
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primary visual cortex- visual stimuli; visual assoc. area- monitors visual cortex & interprets results
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cerebral nuclei
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extra pyrimidal system- sensory info/motor commands outside of conscious awarenss
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limbic system
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in cerebrum, diencephalon & mesencephalon- motivational states, moods & behavior modification; feelings of anger, rage fear, anxiety, docility, pleasure, sex
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limbic system many areas:
amygdaloid body |
heart rate, "fight or flight", emtion to memory, olfaction (smell) w/ emotion & rest of limbic sys.
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hippocampus
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storage/retrival of long-term memories
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insula
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integrate/extrapolate humor, fear, feelings, etc
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mammilary bodies (of hypothalamus)
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feeding reflexes, thirst, body temp.
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anterior nucleus (of thalamus)
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info from mammilary bodies to rest of limbic system
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reticular formation
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heightened alertness/excitement or lethargy and sleep
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limbic lobe and fornix
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connects areas of limbic sys w/rest of brain
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corpus collosum
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cerebral hemispheres to communicate separately or together; "cross talk"
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diencephalon (forebrain):
thalamus |
sensory relay station-processes all incoming sensory stimuli
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hypothalamus
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master controller of endocrine sys-secreates ADH; paraventricular nucleus-oxytocin; tuber cinereum/median eminence- releasing hormones into anterior pituitary; infundibulum connects hypothalamus to pituitary
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pineal gland
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produces melatonin & serotonin
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melatonin
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@ nite- no processing light- regulates circadian rhythms; increases immunity of thymus gland
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serotonin
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during day; processing visual light; helps circadian rhythms
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mesencephalon (midbrain)
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btw thalamus & pons
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mesencephalon cont...
tectum (roof) |
2 sensory nuclei- corpora quadrigemina
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corpora quadrigemina:
superior colliculi |
reflex mvmt of eyes, head, neck- response to visual stimuli
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inferior colliculi
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reflex mvmt of eye, head, neck-response to auditory stimuli
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cranial nerve nuclei: III (occulomotor)
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innervates 4 of 6 eye muscles- medial, superior, inferior rectus & inferior oblique
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cranial nerve cont...
IV (4) trochlear |
innervates superior oblique of eye
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red nucleus
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unconscious muscle tone & posture
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substantia nigra
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dopaminergic neurons- allowing fine motor control
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cerebral penduncles
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desending motor fibers to pons/cerebellum; ascending sensory fibers to thalamus
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reticular activating sys (RAS)
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increases alertness & attentiveness
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rhombencephalon (hindbrain):
metencephalon- cerebellum |
2 lateral hemispheres connected by vermis forming arbor vitae
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cerebellum functions
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adjust posture muscles- maintain balance/equalibrium; fine-tuning mvmts- conscious & subconscious
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ataxia
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lack of balance- inhibition of cerebellum- drugs or stroke
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rhombencephalon (metencephalon):
pons varolli |
control of respiration- apneuistic & pneumotaxic areas
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cranial nerves:
V (5) trigeminal |
innervates jaw & allows facial sensation
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VI (6) abducens
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innervates lateral rectus eye muscle
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VII (7) facial
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innervates muscles of facial expression/ some taste sensation
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VIII (8) vestibulocochlear
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innervates inner ear- hearing and balance; shaes w/ pons in myelencephalon
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myelencephalon:
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medulla oblongata- connects brain to spinal cord; regulates autonomic NS
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cardiovascular center
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adjusts- heart rate, force and flow of blood thru peripheral tissues
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respiratory (medullary) rhythmicity center:
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set pace for resp. drive- apneuistic & pneumontaxic areas; inhibited by opioids
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chemotaxic receptor zone (CRZ)
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vomiting reflex
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IX (9) glossopharyngeal
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innervates pharynx, some taste & carotid reflex
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X (10) Vagus
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innervates entire GI tract- from pharnyx to 2/3 distal transverse colon
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XI (11) accessory
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innervates to traps & sternocleidomastoid
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XII (12) hypoglossal
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innervates tongue musculature nucleus gracilis & cutaneous- pass somatic sensory info to thalamus
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left motor cortex fibers
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cross to right
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right motor cortex fibers
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cross to left
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cerebral motor fibers
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cross
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cerebellar motor fibers
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do not cross
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somatic division of PNS
|
skeletal muscles (voluntary)
|
|
|
autonomic division of PNS
|
smooth/cardiac muscles or glands (involuntary)
|
