Muscles

Front 1

skeletal muscles

Back 1

voluntary striated muscle, attached to one or more ones.

Front 2

striations

Back 2

light and dark transverse bands

Front 3

voluntary

Back 3

subject to conscious control

Front 4

myofiber/muscle fiber

Back 4

skeletal muscle cells

Front 5

sarcolemma

Back 5

plasma membrane

Front 6

sarcoplasm

Back 6

cytoplasm

Front 7

myofibrils

Back 7

long protein cords

Front 8

glycogen

Back 8

starchlike carbohydrate, provides energy for the cell

Front 9

myoglobin

Back 9

red pigment that stores O2 until needed

Front 10

sarcoplasmic reticulum

Back 10

smooth endoplasmic reticulum

Front 11

terminal cristenae

Back 11

end sacs which cross the muscle fiber from one side to the other

Front 12

transverse (T) tubules

Back 12

tubular infoldings which penetrate through the cell & emerge on the other side

Front 13

myofilaments

Back 13

bundle of parallel protein microfilaments

Front 14

thick filament

Back 14

made of a protein called myosin

Front 15

thin filament

Back 15

consist of 2 intertwined strands of proteins- fibrous (F) and globular(G) actins. tropomyosin, troponin

Front 16

elastic filament

Back 16

made of a springy protein called titin

Front 17

contractile proteins

Back 17

myosin and actin; do work of the shortening muscle fiber

Front 18

regulatory proteins

Back 18

tropomyosin and tropinin; act like a switch determining when the fiber can contract

Front 19

A bands

Back 19

dark bands formed by thick filaments that partly overlap the thin filaments

Front 20

I bands

Back 20

lighter bands composed of thin filaments only

Front 21

H bands

Back 21

light region of the A band where the thin filaments do not reach

Front 22

M line

Back 22

dark line in the middle of an H band, where thick filaments are linked through a transverde protein complex

Front 23

Z disc

Back 23

protein disc to which thin filaments and elastic filaments are anchored at each end of a sacromere, appears as narrow are line in the middle of the I band

Front 24

sacromere

Back 24

distance from one Z disc to the next; the contractile unit of a muscle fiber

Front 25

somatic motor fibers

Back 25

axons lead to the skeletal muscles

Front 26

motor unit

Back 26

where muscle fibers behaves as a single functional unit, all the muscle fibers are innervated by it

Front 27

synapse

Back 27

the point where a nerve fiber meets its target cell

Front 28

neuromuscular junction/motor end plate

Back 28

functional connection between the distal end o a nerve fiber and the middle of a muscle fiber

Front 29

synaptic knob

Back 29

dilated tip of a nerve fiber; contains synaptic vesicles

Front 30

synaptic vesicle

Back 30

secretory vesicle in synaptic knob contains acetylcholine

Front 31

acetylcholine (ACh)

Back 31

the neurotransmitter released by a somatic motor fiber that stimulates a skeletal muscle fiber

Front 32

ACh receptor

Back 32

a transmembrane protein in the sarcolemma of the neuromuscular junction that binds to ACh

Front 33

Acetylcholinesterase (AChE)

Back 33

an enzyme in the sarcolemma & basal lamina of the muscle fiber in the synaptic region; responsible for degrading ACh & stopping the stimulation of the muscle fiber

Front 34

action potential

Back 34

quick up & down voltage, from negative RMP to positive value & back to a negative value again ,

Front 35

rigor mortis

Back 35

hardening of the muscles and stiffening of the body that begins after death

Front 36

excitation

Back 36

process which action potentials in nerve fiber lead to action potential in muscle fibers

Front 37

contraction

Back 37

step in which muscle fiber develops tension

Front 38

sliding filament theory

Back 38

thin filaments slide over the thick ones & pull the Z discs behind them, causing each sarcomere as a whole to shorten

Front 39

excitation-contraction coupling

Back 39

link the potentials on the sarcolemma to activation of the myofilaments, preparing them to contract

Front 40

threshold

Back 40

minimum voltage necessary to generate an action potential in the muscle fiber & produce a contraction

Front 41

twitch

Back 41

quick cycle of contraction & relaxation

Front 42

treppe

Back 42

increasing tension with repetitive stimulation, staircase phenomenon

Front 43

isometric contraction

Back 43

contraction without a change in length

Front 44

isotonic contraction

Back 44

contraction with an internal tension builds to the point that it overcomes the resistance

Front 45

concentric contraction

Back 45

muscle shortens as it mains tensions

Front 46

eccentric contraction

Back 46

muscle lengthens as it mains tension