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338 Cards in this Set
- Front
- Back
Muscle cells; elongated
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muscle fibers
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actin and myosin; contraction
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myofilaments
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myo- or mys-
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muscle
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sacro-
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flesh
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-striated
-voluntary -contracts rapidly but tires easily |
skeletal muscle
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-striated
-involuntary -intercalated disks |
cardiac muscle
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-nonstriated
-visceral -involuntary -slow and sustained contractions |
smooth muscle (all hollow organs)
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Functions of muscles
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-movement
-posture -stabilize joints -heat production |
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functional characteristics of muscle
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-excitability or irritability (responds to stimulus; ACh, hormone, pH)
-contractility -extensibility -elasticity (resumes resting length after contraction) |
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Connective tissue coverings of muscles
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-endomysium
-fascicle -epimysium -deep fascia |
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areolar, around each muscle fiber
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endomysium
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bundle of muscle cells covered by a perimysium (collagen)
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fascicle
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surrounds entire muscle (fibrous)
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epimysium
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above epimysium; around muslce and other structures
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deep fascia
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nerves and blood in muscles:
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-every fiber must be attached to a nerve ending
-continuous blood flow brings oxygen and removes wastes -each muscle served by an artery and one or more veins -vessels enter endomysium -capillaries are winding to allow for stretching |
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origin
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immoveable end
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moves toward origin when muscle contracts
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insertion
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fleshy attachments; epimysium fused to periosteum or perichondrium
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direct attachment
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connective tissue wrappings extend as a tendon or aponeurosis to attach muscle
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indirect attachments
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broad and flat while tendon is rope like
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aponeurosis
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the muscles microscopic plasma membrane
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sarcolemma
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produced by union of hundreds of embryonic cells; accounts for large size
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syncytium
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made up of more stored glycogen and contains myoglobin, a rid pigment that binds O2
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sarcoplasm
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-make up the majority of the muscle cell types (80% of cell volume)
-run parallel entire length of cell -tightly packed with other organelles squeezed together |
myofibrils
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compose the myofibrils in chains; functional units of muscles
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sarcomere
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what causes the striations in muscles?
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A and I bands
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-visible in relaxed muscle
-consists of myosin only |
H zone
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boundaries of a sarcomere
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Z discs
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-made of myosin
-dominate A bands |
thick filaments
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-made of actin
-only type in I bands |
thin filaments
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-makes up thick filaments
-has tail and two globular heads -polypeptide chains |
myosin
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heads of myosin that link to actin during contractions
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cross bridges
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each thick filament has __ myosin molecules
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200
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these proteins control actin-myosin binding for contractions
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troponin and tropomyosin
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-made of smooth ER
-surrounds myofibirl with terminal -cisternae (end sacs) at A-I junctions -stores and releases calcium in cells |
sarcoplasmic reticulum
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-continuous with extracellular space
-make up the T system -conduct impulses to every sarcomere in the muscle |
T-Tubules
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the thousands of T-Tubules of each muscle cell
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T system
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-propose in 1954 by Hugh Huxley
-calcium uncovers actin binding sites -thin filaments slide past thick filaments so actin and myosin overlap during the contraction of a muscle -H zones disappear and Z discs get closer |
Sliding filament theory
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the action of myosin heads pivoting as it binds; pulling thin filaments to the center
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power stroke
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cross bridge dettachment occurs as __ binds myosin head and loosens the bond
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ATP
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-hydrolysis of ATP provides energy to return mysoin to high-energy "cocked" position
-repeated over and over as sarcomere shortens |
cocking of myosin head
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-begins 3-4 hours after death with peak at 12 hours
-myosin heads cannot detach due to lack of ATP |
rigor mortis
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the motor neuron, axonal endings on muscle fiber; usually 1 per fiber
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neuromuscular junction
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space between synaptic knob and sarcolema; filled with a gel
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synaptic cleft
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membranous sacs in knob that contain acetylcholine
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synaptic vesicles
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area of sarcolemma that has junctional folds for increased surface area
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Motor end plate
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__ released in knob causes vesicles to release Ach; Ach binds to receptors etc.
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calcium
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a result of positive sodium ions entering to make inside less negative, Na+ gates open and K+
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depolarization
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a period where the muscle cannot be stimulated to produce another action potential
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refractory period
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once initiated, an action potential cannot be stopped and causes full contraction of the fiber; muscles contract completely or not at all
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all-or-none response
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what prevents the muscles from staying contracted?
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acetylcholinesterase (AChE)
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inadequate ACh receptors; destroyed as disease progresses
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myasthenia gravis
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the poison on poison arrow, binds ACh receptors so muscles can't respond
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curare
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time from stimulus until muscle contracts
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latent period
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steps to the sliding filament theory
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1. latent period
2. action potential down T tubules 3. sarcoplasmic reticulum releases calcium 4. calcium removes blocking action of tropomyosin 5. myosin cross bridges attach and shorten sarcomere 6. calcium pump takes calcium back SR for storage 7. tropomyosin again blocks actin active sites |
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a motor neuron and all muscle fibers it supplies
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motor unit
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__ motor units in areas of precise control
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smaller
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graphic recording of a contraction
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myogram
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response of muscle to a single brief threshold stimulus
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muscle twitch
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onset of contraction to peak tension development
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contraction period
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ca 2+ goes back into the SR
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period of relaxation
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two identical stimuli in rapid succession, second twitch will be stronger; muscle already partially contracted (not fully relaxed) and more calcium released; relaxation still occurs
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wave summation
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increase rate of stimulus until relaxation phase disappears; most common
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tetanus
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muscle loses ability to contract due to lack of ATP
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muscle fatigue
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how do our muscles produce different amount of tension?
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recruitment (multiple motor unit summation)
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-staircase efect reflecting increasing Ca 2+ activity
-more heat enhances enzyme activity -contractions increase in strength with each stimulus -bases for warming up in athletics |
treppe
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some motor units active due to spinal reflexes activated by stretch receptors in muscles and tendons
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muscle tone
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force exerted by contracting muscle on an object
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muscle tension
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resistance to movement exerted by an object
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Load
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what does isotonic mean?
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same tone/tension, the muscle changes length and moves load
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muscle shortens; picks up a book etc.
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concentric contractions
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-muscle lengthens
-coordination etc -calf muscle going uphill, quads in a a squat position -50% more forceful but use less O2 and energy, involve fewer fibers |
eccentric
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tension increases but muscle does not change length
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isometeric contractions
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you have 4-6 seconds worth of this; must be regenerated by ADP Phosphorylation
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stored ATP
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high-energy storage molecule
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creatine phosphate
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-CP+ADP------>creatine+ATP; reaction is reversible during inactivity
-catalyzed by creatine kinase -ATP and cp provide maxium power for 15-20 seconds |
ADP phosphorylation
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occurs in mitochondria, requires oxygen; involves several chemical reactions to make ATP
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aerobic respiration
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sum of reactions needed to make ATP; glucose+oxygen---->carbon dioxide+water+ATP
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oxidative phosphorylation
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oxidative phosphorylation (aerobic repiration) yields __ ATP per glucose, but its slow due to the number of steps
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36-38
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necessary when muscles work vigorously for extended periods because working muscles compress vessels and reduce oxygen suppy; glycolisis is used
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anaeroic glycolysis
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glucose-->2 pyruvic acid+2 ATP; occurs in both aerobic and anaerobic respiration
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glycolysis
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during glycolysis, pyruvic acid is converted to __ during anaerobic glycolysis
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latic acid
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in glycolysis, lactic acid is converted to __ by the liver
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pyruvic acid
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gycolysis only produces __% as much ATP as aerobic, but does it 2.5x faster
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5
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what type of events rely on ATP and CP stores?
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sprints, weight lifting, etc.
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sports almost completely fueled by anaerobic
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tennis, soccer
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activities that depend on aerobic respiration
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marathon running, prolonged activities
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the time a muscle can continue to contract using aerobic pathways
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aerobic endurance
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point of switch over to anaerobic respiration
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anaerobic threshold
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-the physiological inability of a muscle to contract
-glycogen and glucose exhausted -results from a relative deficit of ATP, not an absence of ATP when contractures would occur (continuous cross bridges) -lactic acid buildup causes low pH, potassium is lost and excess sodium enters if not enough ATP |
muscle fatigue
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-amount of oxygen that must be taken in following muscle activity to convert lactic acid to pyruvic acid, replace replace glycogen stores, synthesize ATP and CP, liver must convert lactic acid to glucose or glycogen
-difference between O2 needed for completely aerobic respiration that was actually used -in a 100 yd dash, you use 6 L of O2 but VO2 max would be 1.2 L; shortage of 4.8 L -athletes have a higher (10-45%) VO2 max |
oxygen debt
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__ of energy converted to useful work; remainder is given off as heat in muscles
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20-25%
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the force of contraction factors
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-number of muscle fivers contracting: more motor units, more tension
-muscle size: increased area, more tension and greater strength; exercise causes hypertrophy -series-elastic elements: muscle must attach to movable structures and tendons and coverings must be pulled taunt -degree of muscle stretch: optimum length-tension relationship in sarcomere when muscle slightly stretched and actin and myosin barely overlap-maximum sliding can occur |
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the greater the __, the longer the latent period and slower contraction result in shorter duration;
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load
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in isometric contractions where load exceeds force, velocity is __
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zero
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types of muscle fibers
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red slow-twitch, white fast-twitch, and intermediate fast-twitch fibers
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-slow-acting myosin ATPases
-myoglobin, mitochondria, rich capillary supply give it red color -primary energy fuel is fat if oxygen is available -fatigue resistant |
red slow-twitch fibers
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-little myoglobin, therefore pale, few mitochondria
-diameter twice that of red -fast-acting myosin ATPases -large glycogen reserves and depend on anaerobic respiration -fatiguable becasue lactic acid accumulates quickly -brief, intense contractions |
white fast-twitch fibers
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-red or pink with intermediate size
-fast-acting myosin ATPases -high in myoglobin, depend on oxygen and have rich capillary supply like red -somewhat fatigue resistant |
intermediate fast-twitch fibers
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most muscles have a mixture of fibers but in a __, the fibers are all the same type
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motor unit
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marathon runners have __% slow-twitch
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80
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sprinters have __% fast twitch
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60
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increases capillaries, mitochondria, myoglobin, especially in red slow-twitch fibers; hypertrophy of heart, better metabolism and neuromuscular coordination, increases GI movement, better gas exchange in the lungs
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aerobic exercise
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usually anaerobic, isometric with high resistance (weights)
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resistance exercise
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the muscle gets larger
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hypertrophy
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best kind of exercise for overall fitness
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cross-training
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disuse of muscles can lead to __, due to lack of neural stimulation.
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atrophy
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-spindle shaped, small cells with central nuclei; skeletal are 20x wider and thousands of times longer
-endomysium containing vessels and nerves between fibers; no coarser connective tissue sheaths -arranged in sheets or layers in vessels, or hollow organs\-longitudinal and circular layers present in most of above -no striations but thick and thin filaments are present -ratio of thick to thin filaments 1:16 compared to 1:2 in skeletal muscle -tropomyosin but no troponin comoplex |
smooth muscle (microscopic structure)
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alternating contractions of circular and longitudinal muscle
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peristalsis
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bulbus swellings of innervating nerve fibers
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varicosities
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specialized conections between muscle cells that allow AP transmition from cell to cell
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gap junction
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set the pace for contraction some are self-excitory
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pacemaker cells
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mechanism of smooth muscle contraction
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-actin and myosin interact by sliding filament mechanism
-calcium triggers contraction -ATP provides energy for sliding process |
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have slow, sustained contractions that take 30x longer then other muscles types and is very efficient
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smooth muscle
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regulation of smooth muscle contraction
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unlike skeletal; different neurotransmitters have different effects (bronchioles, vessels, etc.)
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-stress-relaxation response: allows hollow organs to fill slowly before contractions are stimulated
-length and tension changes: smooth muscle can create equal tension even when stretched to twice or reduced by 1/2 (total of 150%) while skeletal muscle can only tolerate a 60% change (+ or - 30%) -hyperplasia: division and multiplication of cells (ie uterus) |
special features of smooth muscle
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-contracts rythmically and as a unit
-gap junctions between cells -spontaneous action potentials possible |
single unit (visceral) smooth muscle
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smooth muscles types (occur in digestive and urinary tract)
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single-unit (visceral) and multiunit smooth muscle
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-airways and large arteries, arrector pili, muscles that control pupil size
-independent muscle fibers -rich nerve supply |
multiunit smooth muscle
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disorders and effects of aging on muscles
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-muscular dystrophy
-cramps -strains -age |
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-brought on by a sex linked recesive trait
-muscles destroyed and enlarge du to an increase in fat and connective tissue carried by females and passed on to sons -boys diagnosed at 2-6 years of age and die in their 20's from respiratory failure |
muscular dystrophy
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caused by decreased blood sugar, sodium, calcium, or dehydration
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cramps
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excess stretching, possible tearing due to overuse; inflamation occurs
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strain
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increase in connective tissue, results in a decrease in muscle mass and strength (50% by the age of 80)
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ages effect on muscles
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rigid structure that moves on a fixed fulcrum (joint) when force is applied; possible to move heavier load farther and faster than otherwise possible
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lever
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applied force used to move the resistance or load; muscle contraction
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effort
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work at a mechanical disadvantage; load close to fulcrum and effort applied far from fulcrum
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power levers
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work at a mechanical disadvantage; load far from fulcrum and effort near fulcrum (pitching a ball)
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speed levers
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fulcrum between effort and load; scissors, seesaw, crow bar
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first class lever
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load between effort and fulcrum wheelbarrow, standing on toes
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second class lever
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effort between load and fulcrum; speed, mechanical disadvantages; most skeletal muscles
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third class lever
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straplike or fusiform with an expanded belly most ability to shorten, but not as powerful
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parallel fascicle arrangement
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short fascicles that attach obliquely to a central tendon (uni-, bi-, and multipennate)
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pennate fascicle arrangement
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broad origin and fascicles converge toward single tendon
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convergent fascicle arrangement
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concentric rings of fascicles; sphincters or bicularis oris and occuli
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circular fascicle arrangement
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muscles can only shorten and usually __ moves toward __
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insertion, origin
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-agonists
-provide major force for movement |
prime movers
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-oppose/reverse a particular movement
-may regulate action of prime mover -found on opposite side of joint from prime mover |
antagonists
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aid agonists by promoting the same movement or reduce undesirable movements
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synergists
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the ways to name muscles
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-location
-shape -relative size -direction of fibers -number of origins -origin or insertion location -action of muscle |
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bone the muscle lies over, around mouth, medius, lateralis, profoundus (deep), superficialis
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examples of naming a muscle based on location
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deltoid is triangular, obicularis, latissimus (widest)
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examples of naming a muscle based on shape
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longus, brevis, maximus, major, minor, magnus, vastus
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examples of naming a muscle based on relative size
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rectus (straight), oblique
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examples of naming a muscle based on direction of fibers
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quadricepts, biceps, triceps
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examples of naming a muscle based on number of origins
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thyohiod, frontalis, supraspinatus
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examples of naming a muscle based on origin or insertion
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adductor, abductor, extensor, supinator, pronator
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examples of naming a muscle based on action of muscle
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__ and endocrine system regulates and maintains homeostasis through electrical signals
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nervous system
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functions of the nervous system
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-sensory: sensory receptors monitor internal and external changes or stimuli
-integration: processes and interprets sensory input -motor output: response by effecto organs (muscles and glands) |
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organization of the nervous system
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-central nervous system
-peripheral nervous system |
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-made up of the brain and spinal chord
-found in the dorsal body cavity -integrates and controls effectors |
central nervous system
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-made up of spinal and cranial nerves to and from the spinal cord and brain
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peripheral nervous system
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functional division of the peripheral nervous system
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-sensory (afferent): somatic and visceral afferents
-motor (efferent): to muscles and glands |
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the subdivisions of the motor (efferent) part of the peripheral nervous system
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-somatic nervous system: voluntary nervous system, skeletal muscle control
-autonomic nervous system (ANS): fibers regulating smooth and cardiac muscles and glands; involuntary nervous system (divided into sympathetic and parasympathetic divisions) |
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the nervous system consists of __ and __.
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neurons and supporting cells
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-smaller than neurons
-glia:neurons ratio=50:1 -make up half of the brains mass |
CNS neuroglia
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the types of CNS neuroglia cells
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-astrocytes
-microglia -ependymal cells -oligodendrocytes |
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-most abundant kind of neuroglia, star-shaped cells
-wrap around capillaries and neurons; form barriers between the two -antigen:presentors--->stimulates immune system |
astrocytes
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-have spiny processes
-macrophages |
microglia
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-squamous to columnar in shape, many ciliated to circulate CSF
-form barrier between CSF and tissue |
ependymal cells
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-cytoplasmic extensions around thicker neurons (in the CNS)
-produce myelin sheath (insulator) |
oligodendrocytes ("few branches")
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neuroglia cells of the PNS
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satellite cells and schwann cells
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surround cell bodies in ganglia and may control chemical environment of associated neurons
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satellite cells
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form myelin sheaths around larger fibers and act as phagocytes
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schwann cells
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characteristics of neurons
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-longevity: 100+ years
-amitotic: cannot reproduce -high metabolic rate: need a consistent supply of O2 and glucose |
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-often called the soma or perikaryon
-is biosynthetic: makes brain chemicals (neurontransmitters) -no centriols--->NO MITOSIS -have nissl bodies: rough ER -have elaborate golgi apparati |
the cell body
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clusters of cell bodies in the CNS
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nuclei
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clusters of cell bodies in the PNS
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ganglia
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bundles of neuron processes in the CNS
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tracts
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bundles of neuron processes in the PNS
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nerves
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-input regions with great surface area
-recieves impules from neighboring axons and delivers them to the cell body |
dendrites
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cone-shaped area of cell body leading to axon
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axon hillock
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long axons (lumbar to toes are 3-4 ft long)
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nerve fibers
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right angles from axon; may or may not be present
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axon collaterals
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end-branches (10,000 or more per axon); aka axonal terminal, synaptic knobs
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telodendria
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-one per neuron
-conducting components that generate and transmit nerve impulses -neurotransmitters in ending excite or inhibit -no nissl bodies and therefore degenerate rapidly if cut |
axon
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-larger in diameter, longer neurons usually myelinated
-myelin protects, insulates, and increaeses speed of transmission -only axons are myelinated, not dendrites |
myelinated fibers
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conduct up to 150x slower than myelinated fibers (1 m/s vs 150 m/s
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unmyelinated fibers
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sheath of schwann cell around myelin sheath that contains cytoplasm and nucleus
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neurilemma
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gaps between adjacent schwann cells
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nodes of ranvier
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impulse jumps from node of ranvier to node of ranvier
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saltatory conductoin
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myelinated fibers in the CNS
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white matter
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nerve cell bodies and unmyinated fibers in the CNS
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gray matter
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structural classification of neurons
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-multipolar
-bipolar -unipolar |
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-3 or more processes
-most common kind of structural neuron -CNS |
multipolar
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axon and dendrite (2 processes) on opposite sides of cell body; rare in adults except special senses as receptors (eye and nose)
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bipolar
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single process from cell body with T-like proximal and distal fibers
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unipolar
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functional neuron classification
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-sensory or afferent
-association or interneurons -motor or efferent |
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-cell bodies in sensory ganglia outside CNS
-only distal areas are receptors |
Sensory or afferant neurons
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-multipolar
-entirely in CNS -99% of the bodies neurons -integration or interpretaion |
association or interneurons
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-impulses away from CNS
-primarily multipolar -cell bodies in CNS -form junctions with effector cells |
motor or efferent neurons
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electricity measured in volts or milivolts between two points
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potential difference or potential
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in the plasma membrane of a neuron; each is selective.
two types: 1. passive or leakage 2. active or gated -chemically gated (transmitter-gated) -voltage-gated or voltage dependent due to changes in membrane potential |
ion channels
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-approximately -70mV across cell membrane
-membrane is polarized -due to high Na+ outside and K+ inside of the cells and the high concentration of ANIONIC PROTEINS inside of the cell -maintained by differential permeability of membrane and sodium-potassium pump |
resting membrane potential
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ejects 3 Na+ while transporting 2 K+ back into the cell
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Na+-K+ pump
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reduction in membrane potential; becomes less negative than resting potential
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depolarization
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membrane more negative or further from zero
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hyperpolarization
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-nerve and muscle cells communicate primarily by these
-called a nerve impulse in nervous tissue -voltage gated channels open -only occur in axons |
Action potentials
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AP generation (4 steps)
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1. resting state
2. depolarization (sodium permeability increases Na+ enters the cell) 3. repolarization (potassium gates open, decline in Na+ permiability) 4. undershoot (hyperpolarization) |
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positive ions in axoplam move toward area that is stillnegative (polarized)
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AP propagation
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-strong stimulus causes threshold to be reached more quickly while weak stimuli must be repeated to achieve teh necessary current flow
-AP happens completley or not at all |
all-or-none-response
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period where nerve is incapable of responding to another stimulus
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absolute refractory period
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sodium gates are closed, potassium gates open and repolarizatin is occurring; threshold is higher than resting cell
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relative refractory period
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factors affecting the speed of impluses
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-axon diameter: larger, faster due to decrease in resistance
-myelination: faster due to saltatory conduction |
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a disorder in which demyelination occurs
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MS
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somatic sensory and motor to skin, skeletal muscles and joints; large and myelinated; fast (15-150 m/s)
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group A fibers
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ANS motor, visceral sensory and smaller somatic sensory form skin (pain and small touch); lightly myelinated with intermediate diameter (3-15 m/s)
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group B fibers
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smallest diameter and unmyelinated; slow (1 m/s)
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group C fibers
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the transfer of information from one neuron to another or an effector cell
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synapse
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impulses toward teh synapse
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presynaptic neuron
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electrical signals away from the synapse
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postsynaptic neuron
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-bridge gaps (like gap junctions)
-protein channels allow current-carrying ions to flow from neuron to neuron -snchronize activity of interconnected neurons -more abundant in embryonic nerve tissue and most replaced by chemical |
electrical synapses
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open or close ion channels
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neurotransmitters
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-axonal terminal of presynaptic neuron with synaptic vesicles that store neurotransmitter
-receptor region on postsynaptic membrane that has neurotransmitter receptors -synaptic cleft |
chemical synapses
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separates the two; neurotransmitter must be released, diffuse and bind to receptors so that communication is UNIDIRECTIONAL
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synaptic cleft
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-AChE (acetylcholinesterase) or other enzyme
-reuptake into presynaptic terminal -diffusion away from synapse |
methods of neurotransmitter control
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time it takes for above synaptic steps to occur
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synaptic delay
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-ACh
-biogenic amines: 1. catecholamines (dopamine) 2. indolamines: serotonin and histamine -amino acids: GABA, glycine etc -peptides: endorphins -novel messengers: ATP, nitrous oxide |
different types of neurotransmitters
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psychoactive drugs like LSD bind to ___
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biogenic amine receptors
|
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alzheimers patients have a ___ deficiency
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ACh
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funcitonal classification of neurotranmittres
|
-excitatory: cause depolarization
-inhibitory: cause hyperpolarization |
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direct (open ion channels; ACh, AA) and indirect (intracellular second messengers)
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mechanism of action of neurotranmitters
|
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-system works in an all-or-nothing manner
-domino type-rapid and predictable -reflexes 1. rapid, automatic responses 2. 5 compenents |
serial procesing
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inputs follow many paths to different areas of the CNS; same stimulus promotes many responses (such as odors)
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parallel processing
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becomes the cerebrum
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telencephalon
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becomes teh thalamus, hypothalamus, and epithalamus
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diencephalon
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turns into the midbrain of teh brainstem
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mesencephalon
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becomes the brainstem, pons, and cerebellum
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metencephalon
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becomes the brainstem
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myelencephalon
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regions of the brain
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-cerebral hemispheres
-diencephalon (thalamus, hypothalamus, and epithalamus) -brainstem (mid brain, pons, medula) -cerebellum |
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83% of total brain mass
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cerebral hemisphere
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ridges on the surface seperated by grooves called sulci
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gyri
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deeper grooves separating brain regions (made up of longitudinal and transverse)
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fissures
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the fissure between hemispheres
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longitudinal
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fissure between cerbrum and cerebellum
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transverse fissure
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lobes of the brain
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-frontal
-parietal -occipital -temporal -insula |
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-seat of consciousnes, (preception, communication, memory, voluntary movements, etc.)
-gray matter consisting of cell bodies, dendrites, and unmyelinated axons, glia, and vessels --NO fiber tracts -2-4 mm thick but convolutions increase surface area so it creates 40% of brain mass |
cerebral cortex
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motor, sensory, and association, but no sensory or motor neurons
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the cerebral cortex
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generally control motor and sensory functions of opposite side
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the hemispheres of the cerebral cortex
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motor areas of the cerebral cortex
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-primary motor cortex
-premotor cortex -broca's area -frontal eye field |
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-in the frontal love of each side
-skeletal muscle control -pyramidal cells: large, skeletal muscle control -contralateral (right side controls left side of the body) |
primary motor cortex
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the theory that there is a left and right side of the brain and they function differently
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lateralization
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-controls learned repetative motor skills (dribbling, batting, piano)
-coordinates movements |
premotor cortex
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-present in only one hemisphere (usually the left)
-motor speech area that controls tongue, throat, and lips -also likely to be important in planning what you are about to say |
brochas area
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controls voluntary eye movements
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frontal eye field
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sensory areas of the cerebral cortex
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-primary somatosensory cortex
-somatosensory association areas -visual areas -auditory areas -olfactory cortex -gustatory cortex |
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-recieves information from somatic sensory receptors in skin and proprioceptors to identify body area stimulated
-contralateral (opposite sides) -more sensative ares have a higher amount of sensory corxtex devoted to them. |
primary somatosensory cortex
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integrates adn analyzes somatic sensory inputs (temperature, pressure, size, etc.)
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somatosensory association area's
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visual areas of the cerebral cortex
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-primary visual cortex
-visual association areas |
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largest cortical sensory area, from retinas
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primary visual cortex
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interprets and evaluates visual stimuli in light of past visual experiences so we recognize people, places, things
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visual association area
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auditory areas of the cerebral cortex
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-primary auditory cortex
-auditory association area |
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-determines pitch, rythem, and loudness from cochlea
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primary auditory cortex
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perception of sound such as speech, music, thunder, noise, etc.
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auditory association area
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odois, sense of smell
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olfactory cortex
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perceives taste
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gustatroy cortex
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association areas of the cerebral cortex
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-prefrontal cortex
-general interpretaion area -language areas -visceral association area |
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intellect and complex learning (cognition), personality
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prefrontal cortex
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only in one hemisphere, usually the left; storage of complex memory patterns associated with sensation
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general interpretation area
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conscious perception of visceral sensations (feeling full and needing to go to the bathroom)
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visceral association area
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__% of people are left brain dominant
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90
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nondominant hemisphere is usually involved in __
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intuition, emotion, art appreciation
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__% of population is right hemisphere dominent; many left handed, more males
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10
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__ may result in dexterity, ambidexterity, or things like dislexia due to cerebral confusion
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lack of cerebral dominance
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-provides communicaiton between cerebral areas, cerebrum, and lower CNS centers; primarily large mylinated fibers bundled into tracts
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cerebral white matter
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largest commisure superior to lateral ventricles
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corpus callosum
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-caudate nucleus, putamen, and globus palliidus
-receive inputs from cerebral cortex, other subcortical nuclei and on another -cognition -starting, stopping, and monitoring movements ordered by cortex (arm swinging while walking) -inhibits uncessary movements |
basal nuclei
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parkinsons, huntingtons disease tourettes, OCD
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disordrs of basal nuclei
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made up of the thalamus, hypothalamus, and epithalamus
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diencephalon
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-80% of the dienchephalon
-afferent impulses enter fro all senses and body parts to synapse at least once in teh thalamus; many nuclei -edits information and relays it into teh correct sensory cortex and association center |
thalamus
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made up of mammillary bodies and infundibulu
-is teh autonomic control center: blood pressure, heart rate, breathing, digestive motility -emotional response and behavior: connects with cortical assocition areas and lower brain stem; the heart of the limbic system -body temp regulation -hunger -thirst -sleep-wake cycles -endocrine control center |
hypothalamus
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on anteriour surface (bulges)-olfactory relay stations
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mammillary bodies
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connects pituitary gland and hypothalamus
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infundibulum
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contains the pineal gland and choriod plexus's
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epithalamus
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secretes melatonin, helps to regulate sleep-wake cycles, moods, also secretes seratonin
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pineal gland
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found in epithalamus, secretes CSF
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choriod plexus's
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made up of the midbrain, the pons, and the medulla oblongata
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brainstem
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-cerebral aquaduct: connects 3rd and 4th ventricle
-substantia nigra-black due to melanin, precursor of dopmine |
midbrain
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disease associated with the neurotranmitter dopmine
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parkinsons disease
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-conduction tracts (pons+bridge)
-serveral crainial nerve pairs originate here -pneumotaxic center: maintaing normal rythhm for breathing |
pons
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-pyramids: on ventral aspect; longitudinal ridges formed by tracts from motor cortex
decussation of pyramids: fibers cross over just above spinal cord-medulla junction creating contralateral brain affects -crainial nerves here |
medulla oblongata
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-cardiovascular center
1. cardiac center: force and rate of contractoin 2. vasomotor center: blood pressure via smooth muscles in vessels -repiratory centers: rate and depth of breathing with pons -other centers induce vomit, hiccup, swallowing, cough, and sneeing |
the functions of the brainstem
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pleatlike gyri; convoluted
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folia (found in cerebellum)
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treelike apperance within cross section (found in cerebellum)
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arbor vitae
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function of the cerebellum
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balance and coordination
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-found in cerebral hemispheres and diencephalon
-emotional or affective brain (feelings -smeels (links to memory) -explains how feelings can override logic |
limbic system
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-found in central core of medulla, pons, and midbrain
-Reticular activating system (RAS): determines consciousness of cerebral cortex; diregards about 99% of sensory stimulii as unimportant) |
Reticular formation
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measures neuronal electrical activity in the brain
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EEG
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waves our brain gives off when we are relaxed
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alpha waves
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waves given off when we're concentrating
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beta waves
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waves given off by most childrens brains
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theta waves
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waves given off in deep sleep or when brain damage occurs
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delta waves
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abnormal brain waves
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seizure
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low O2 use and total unresponsiveness to stimulii
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coma
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partial consciousness that you can be aroused from
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sleep
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first 30-40 minutes of sleep; 4 stages
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NREM (non rapid eye movement ) sleep
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stage 4 NREM; delta waves-hard to wake up
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slow-wave sleep
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revert through stages to stage 1; alpha waves appear and dream occurs
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REM sleep
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you have REM sleep every __ min, each a little longer from 5-50 minutes
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90
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the inability to sleep
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insomnia
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storage and retrieval of information
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memory
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stages of memory
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1. short term: working memory
2. long term memory: unlimited capacity but declines with age |
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-emotional state: norepinephrin involved
-rehearsal -association: link to old memories -automatic memory: not conscious |
ways to tranfer from from ST to LT memory
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memory based on names, dates, and numbers
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fact memory
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memory that is experience based
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nondeclaritive memory
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memory like brushing your teeth, playing a scale, dribbling the ball
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skill memory
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protections of the brain
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-menijies
-dural septa -CSF -blood brain barrier |
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-cover and protect CNS
-contain CSF -form skull partitions -made up of dura mater, arachnoid mater, and pia mater |
meijies
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-double layered, most external membrane of brain
-periosteal layer attached to inner skull surface -inner meningeal layer dural sinuses collect venous blood to internal jugular veins |
dura mater
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-subdural space: between dura and arachnoid
-subarachnoid space: between arachnoid and pia mater; filled with CSF -web-like -arachnoid vili: knobblike projections of arachnoid through dura |
arachnoid mater
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thin layer clinging to brains surface and spinal cord
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pia mater
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-falx cerebri: into longitudinal fissure between cerebral hemispheres; ttaches to critstia galli
-falx cerebelli: forms midline partition along vermis -tentorium cerebelli: into tranverse fissure |
dural septa
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-reduces brain weight by 97% and protects brain and spinal cord from trauma , nurishes
-less protien and more vitament C than plasma; ions differ made by the choroid plexuses: hang from roof of each ventricle and form CSF |
CSF
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-maintains stable environment for the brain
-blood-borne substances in brain capillaries sepearted from EC space and neurons primarily by: a. endothelian of capillar wall, tight junction , least permiable b. other mechanisms -is a selective barrier except to fat-soluble molecules (alcohol, nicotine, aspirn) difficult to treat diseases -absent in areas such as the vomiting center, hypothalamus (so that it can monitor whats going on in the blood) |
Blood brain barrier
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slight injury but no permanent damage to the brain
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concussion
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tissue destruction in brain
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contusion
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blow results in bleeding of brain
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subdural or subarachnoid hemorrhage
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swelling of the brain following injury, steriods also cause this
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cerebral edema
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cerebrovascular accidents or CVA's
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strokes
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deprivation of blood to any tissue
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ischemia
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__% of those with massive CVA die in first attack
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80
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incomplete strokes; reversible; cerebral ischemia
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transischemic attacks (TIA's)
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-results in dementia
-one half of nursing home patients (other 50% CVA's) -deficit of ACh and structural changes in the brain -genetic |
alzheimers disease
|
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-degeneration of dopmine-releasing neurons of substatia nigra in teh brain stem
-basal nuclei become overactive -tremors, forward-bent posture, shuffling gait, lack of expresssions -treatment includes L-dopa and artificail dopamine agaonists -fetal substantia nigra tissue transplants |
parkinsons disease
|
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-hereditary disease
-massive degeneration of teh basal nuclei and the cerebral cortex -jerky movements -opposite of parkinsons disease -treated with dopamine blockers -progressive and fatal within 15 years of onset |
huntingtons disease
|
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-sends information to and from the brain
-reflex center |
spinal cord
|
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fat and veins for padding in the spinal cord
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epidural space
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in the spinal cord, CSF is found in the __
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subarachnoid space
|
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contains the nerves that go to the arms
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cervical spinal chord enlargement
|
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contains nerves going to the legs
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lumbar spinal cord enlargement
|
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nerve roots at the exterior ends
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cauda equina
|
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infromation goes intro the spinal cord through the __ horns and leaves through the __
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dorsal, ventral
|
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destruction of anterior horn (motor neurons)
affects muscle control in one area of the body |
poliomyelitis
|
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damage to ventral root or anterior horn cells; lower motor neurons damaged
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flaccid paralysis
|
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upper motor neurons of primary motor cortex damaged with spinal motor intact, causing constant stimulation by spinal reflexes; muscles remain healthy but not voluntarily contractible
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spastic paralysis
|
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damage of the thorax-lumbar spinal cord
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paraplegia
|
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cervical spinal cord damage
|
quadriplegia
|
|
due to cord injury; paralysis permanent if function doesn't resume with in 48 hours
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spinal shock
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