Ch 7 (test 1) Flashcards
Describe the 6 steps that take place for transmission of impulses from nerve to sketetal muscle
1) AP reaches axon terminal
2) Voltage gated Ca channel opens and moves down concentration gradient to cell
3) Ca enters neuron
4) Vesicles move to membrane and release Ach
5) Ach binds to receptors, Na comes into cell
6) Propagation of AP
How can Ach be removed from the synaptic space
1) Acetylcholinesterase–breaks down Ach
2) Diffuse out
Ach gated Na channel lets Na move in or out of the cell
in
What sheath covers the whole muscle fiber, a bundle of muscle fibers and a single muscle fiber
epimysium
perimysium
endomysium
myofibril contains what filaments
actin and myosin filaments
inward projection of plasma membranes
transverse tubules
what is the triad of the reticulum made up of
1) plasma membrane
2) Sarcoplasmic Reticulum
3) Myofibrils
what does the sarcoplasmic reticulum store
Calcium
2 purposes of the transverse tubules
- increase surface area of membrane
- brings AP close to sarcoplasmic reticulum and myofibrils
the process by which transmission of an AP down a T tubule increases intramuscular Ca concentrations to initiate muscle contraction
Excitation contraction coupling
During excitation contraction coupling, the lack of an AP causes what
the closure of Ca release channel by the DHP receptor
another name for the Ca release channel
ryanodine receptor
Thin myofibril filament
actin
troponin
tropomyosin
thick myofibril
myosin
troponin binds to what
Calcium
