PHYSIOLOGY
MUSCLE CONTRACTION
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Voltage-gated channels open, releasing sodium
|
|
|
Voltage-gated channels open, releasing acetylcholinesterase
|
|
|
Voltage-gated channels open, releasing acetylcholine
|
|
|
Voltage-gated channels open, releasing calcium
|
Detailed explanation-1: -When the action potential reaches the terminal, it activates voltage-dependent calcium channels, allowing calcium ions to flow into theterminal. In the resting state, neurotransmitters are stored in vesicles at the pre-synaptic terminal.
Detailed explanation-2: -When an action potential reaches the axon terminal it depolarizes the membrane and opens voltage-gated Na+ channels. Na+ ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated Ca2+ channels to open.
Detailed explanation-3: -[11] In unmyelinated axons, depolarization of the cell membrane must spread to the immediately adjacent region of the membrane, raising the potential passively until reaching the threshold voltage. Thus, the action potential propagates as a continuous wave of depolarization.