Moto Muscle Flashcards
depolarization of the T tubule is directly linked to the opening of Ca2+ channels on the SR of
skeletal muscles only
what muscle types have calcium-induced calcium release?
cardiac and smooth muscle
at the muscle EPP, ACh causes the opening of what channels?
Na+ and K+ channels = depolarization to a value halfway between Ena and Ek
how can the end plate of a normally innervated skeletal muscle be distinguished form the rest of the cell membrane?
will initiate a contraction in response to the local application of acetylcholine
what is the only region in muscle that has receptor for ACh?
end plate region
what produces the end plate potential in skeletal muscle?
Na+ influx into the cell - results from the increase in Na+ permeability that occurs with ACh binding to the nicotinic receptors on the membrane of the motor end plate
does smooth muscle require an AP?
no
what does smooth muscle contract in response to?
any stimulus that increases the cytosolic Ca2+ concentration = Ca2+ channel openers, sub threshold depolarization, tissues factors, circulating hormones that stimulate the release of intracellular Ca2+ stores
smooth muscles last ____ and uses less ___ compared to skeletal muscle
longer
less energy
___ muscle contraction is heavily ___ dependent
Ca2+
when does production occur, with the application of what?
preload
during an isometric contraction, what is required to maintain active tension?
troponin bound Ca2+
during resting condition, are myosin and actin bound?
no - which allows for easy sliding of the thick and thin filaments past one another.
is ATP required to FORM the crosslink between actin and myosin?
No - its required to detach the two
what is the ryanodine receptor channel?
on SR, has to do with calcium
