PHYSIOLOGY
MUSCLE CONTRACTION
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Sarcolemma becomes temporarily permeable to sodium.
|
|
|
The muscle contracts.
|
|
|
Calcium is pumped into the axon terminal.
|
|
|
Synaptic vesicles move to the end of the terminal.
|
Detailed explanation-1: -Neurotransmitter attaches to receptors on the sarcolemma. Sarcolemma becomes temporarily permeable to sodium (Na+) that rushes into the cell giving it a positive charge. Sodium rushing into the cell generates an action potential. Once started muscle contraction cannot be stopped.
Detailed explanation-2: -When acetylcholine binds to these two chains, the shape of the entire receptor changes slightly, opening the channel. This allows positively charged ions, such as sodium, potassium, and calcium, to cross the membrane.
Detailed explanation-3: -Acetylcholine causes f. the opening of ligand-gated cation channels. More specifically. this neurotransmitter will cause the opening of sodium channels, which will result in a large influx of sodium ions, causing a depolarization of the motor endplate, which will eventually lead to a muscle contraction.