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

Answer: (D)

Transmission of nerve impulse through nerve fibre occurs unidirectionally because axon of one neuron linked to the dendrite of another neurone through synapse. Synaptic vesicles are filled with a neurotransmitter (e.g., Acetylcholine) released by axone endings not by dendrites.