Question

Indicate the order of events for how an action potential will transmit across a chemical synapse.I. Synaptic vesicles fuse to the plasma membrane.II. Neurotransmitters are released into the synaptic cleft.III. Voltage-Gated Calcium channels open allowing an influx of calcium ions.IV. An action potential reaches the end of an axon.a. IV, III, I, II. b. III, I, II, IV. c. IV, II, I, III. d. IV, III, II, I.

Answer 1

Answer:

B

Explanation:

once neurotransmitters are released into the synaptic cleft, it binds to its receptors at the postsynaptic membrane. voltage gated calcium channels open and allows calcium to flow in, an action potential is generated immediately and reaches the end of the axon

Answer 2

Answer:

a. IV, III, I, II.

Explanation:

This is a  pathway of  transmission of action potential   across a synaptic gap of  pre-synaptic and postsynaptic neurons, or from pre-synaptic neuron and a muscles cells at a neuromuscular junction.

It is initiated with the  arrival  of action potential at the pre-synaptic neuron, which makes voltage gated Ca+ ions to open, vesicles migrates towards the tip of the pre-synaptic neurons, fused and empty  contents into the synaptic cleft, the neurotransmitter pass across the synaptic cleft to reach the post synaptic neuron.

 The  action potential  transmitted  across the synapse  can either be Inhibitory post synaptic or excitatory postsynaptic potential.

The neurotransmitter  released into the synapse  binds with the receptors on the postsynaptic neurons. And this enabled the Act.potential to  be propagated to the postsynaptic neuronal axon, to open  many Voltage-Gated Sodium channels for depolarization, and propagation of action potential.

The neurotransmitters can be exictatory or inhibitory. In either case they are broken down to components molecules, by enzymes after short period of binding with the postsynaptic potential. This is important  so that they do not exert too much  effects  on the post synaptic  receptors which  may affect the action  potential  in the effectors or  in the postsynaptic neurons functions.