Question

Unidirectional transmission of a nerve impulse through nerve fibre is due to the fact that,

• A. Nerve fibre is insulated by a medullary sheath.
• B. Sodium pump starts operating only at the cyton and then continues into the nerve fibre.
• C. Neurotransmitters are released by dendrites and not by axon endings.
• D. Neurotransmitters are released by the axon endings and not by dendrites.

Answer 1

The correct option is D Neurotransmitters are released by the axon endings and not by dendrites.

Unidirectional transmission of a nerve impulse through nerve fiber is due to the fact, that neurotransmitters are released by the axon endings and not by dendrites. The axonal terminals are specialized to release the electrical impulse of the presynaptic cell. Neurotransmitters are packaged into synaptic vesicles that cluster beneath the axon terminal membrane on the presynaptic side of a synapse. The axonal terminals are specialized to release the electrical impulse of the presynaptic cell. The terminals release transmitter substances into a gap called the synaptic cleft between the terminals and the dendrites of the next neuron. The information is received by the dendrite receptors of the postsynaptic cell that are connected to it. Neurons don't touch each other but communicate across the synapse. So, the correct answer is option D.