Question

_The endplate potential (EPP) at the frog neuromuscular junction occurs because ACh simultaneously increases the conductance of the postsynaptic membrane to Na and K

Answer 1

Complete question:

The endplate potential (EPP) at the frog neuromuscular junction occurs because ACh simultaneously increases the conductance of the postsynaptic membrane to Na and K

• True
• False

Answer:

TRUE

Explanation:

The Acetylcholine neurotransmitter is released from the presynaptic cell by the process of exocytosis.

Once the molecule is in the intercellular space, it moves forward the postsynaptic membrane to join its receptor in the motor plate.

Once the joining has occurred, the receptor acquires a channel shape allowing the ion transference that will make possible the modification of the action potential. Ions traffic will consist of the pass of sodium and calcium to the interior of the cell and potassium to the exterior. Quantitatively, the interchange Na-K is the most significant.

K+ follows a concentration gradient, while Na+ follows an electrochemical gradient. The interchange results in an increase of positive charges in the interior of the muscular cell.

Whenever there is a sufficient number of Acetylcholine receptors are active, the depolarization threshold of the motor endplate is exceeded. This activates an action potential that extends to the rest of the muscle membrane.