Synaptic transmission Flashcards
how many muscle cells can a pre-synaptic neuron innervate?
1 or more
muscle cell can get signal from how many pre-synaptic neurons?
only 1
contents of one vesicle is how many quanta of ACh?
one
each quanta increases membrane potential a little. what is this called?
miniature end plate potential
if you maintain depolarization in synaptic cleft for a long time (succinylcholine), what happens to threshold potential of adjacent tissue?
increases
what steps occur for contraction to take place?
- action potential travels down t tubules
- DHP receptor opens (changes shape)
- ^ causes ryanidine receptor to release Ca2+
- ^ Ca2+ binds to troponin, opening up tropomyosin, opening up myosin binding sites on actin
- CONTRACTION
function of titin?
provides elasticity and stabilizes myosin
in rigor mortis (death), what has happened to the myosin?
it is still attached to actin bc no ATP is available to detach it (results in rigor)
during relaxation of muscle, what pump is used?
Ca+/ATPase pump
what is central fatigue?
perception of fatigue possibly brought on by increasing levels of byproducts of contraction (hydrogen ion, lactic acid)
what is peripheral fatigue?
lack of energy in muscle, lactic acid will buildup
force of contraction is dependent on what?
starting length of sarcomere (max force generated near middle of length extremes)
what muscle conditions do you want to avoid in order to get peak contraction (very important for heart)?
for optimal contraction, you don’t want an already contracted muscle or a very stretched out muscle
*think of length - tension dependent force
what is tetanus?
overlap of twitches, complete relaxation isn’t achieved
greater the frequency of stimulation, the (greater/lesser) the potential force?
greater
