Notes

isotonic contraction-maintains force velocity curve
isometric contraction- a contraction is a force not enough to lift something, holding a weight in place

concentric contraction- muscle shortens
eccentric contraction - muscle increases in length
bicep-tricep

series elastic component

tendons form the series elastic component

length-tension relationship
-cross bridge broken when maximum contraction is reached

starts by using plasma free fatty acid and plasma , then using muscle glycogen and it causes fatigue

V0sub2-maximum oxygen uptake, maximum rate of muscle contraction at a time, 12ml of O2/kg, to 84 ml of O2/kg

high altitude promotes the release of erthyoprothen produces more blood cells

lactate threshhold-point in maximum uptake where you see significant levels of lactate in blood, 50-70% of VO2 max

oxygen debt- lack of oxygen when muscle is depleted of oxygen, oxygen is needed to break down lactate

phosphocreatine- increase energy stored in muscles, phosphocreatine kinase transfer energy to kinase; excess level in Blood Stream indicates muscle damage( heart or muscle) used to diagnose muscular dystrophy. synthesized my liver and kidneys;

types of muscle fibers- slow twitch and fast twitch-based on myosin atpase, slow lasts longer

pahsic muscle-
postral muscle- maintain posture; muscle on spine; tend to have slow oxidatie fibers and have more myoglobin; look really red; red fiber

fast twitch are called white fibers-
type 2 a- fast oxidative
2b-fast; humans don't have 2b
2x-really fast

z-line contains the anchoring proteins: narrower z-line in fast twitch you want less titin less resistance;lots of glycogen in fast twitching

fast-twitch susceptible to fatigue

muscle fatigue- physiological occurrence : build up of lactic acid decreases the ph and reduced excitation coupling, or increase free phosphates, or decline in ATP, hinder K+ and Na+, decreased glycogen; body will reestablish storage, too much ADP decreases velocity of muscle contraction, K+ accumulation

central fatigue not actual fatigue to prevent over exertion of muscles

training increases fat stored in tissues; less fat stored in tissues;

endurance training- training your msucles to resist fatigue, increase lipase, myoglobin, less latic acid produced, decreases 2x and increases 2a

resistance training- lifting weight, muscle size, muscle absorb satellite cells that do divide, increase the amount of cappilaryies

damage is repaired by the absorbtion of more sattelite cells, older people end up losing satellite cells, TGF theta(prevent the division of sattelite cells) myostatin- prevent satellite cells from fusing with muscle,
titin-attached ti z-disc

nubulin

obscurin

motor nuerons are found w/i spinal cord also known as final common pathway(whatever signal goes), cell bodies of lower neuron found in gray mass, leave from ventral side(ventral roots) dorsal roots are sensory

mutation in superoxidismutase release free radicals causes ALS

golgi tendon organs- position of muscle/tension

muscle spindle apparatus- length
combine for coordination

spinlde appartus- have thin cells called infusal fibers, insert into tendons, parallel in direction to extra fusal, lack the contractual appartus, have mucleaf bag fivers, nuclear chain fibers(arranged in rows)

primary sensory endings- annual spiral,flower spray endings; stretches when muscle streaches, can also regulation the rate of contraction

coactivation- stimualte the intrafusal fibers at the same time so there is no rapid change in signal and overrides the antistrech information,

involuntary control- skeletal muscle is voluntary but involuntary regulated

monosympatic strach reflex- one neuron to be activated usully more than one though, very basic receptor that will jump the muscle: knee jerk reflex

golgi tendon organ- proprioception, have innervation from sensory neuron that is inhibitory, senses to much tension, negative reaction, which will then decrease the magnitude of the contraction

reciprocal innervation will contribute to the final signal sent to alpha motor neuron

flacid paralysis- reduced muscle tone caused by damage to lower motor nuerons

spastic paraylsis- increasd muscle tone dmage to upper motor nueons

babinsky sign
plantar reflex