Question

Assertion :Transmission of the nerve impulse across a synapse is accomplished by neurotransmitters. Reason: Transmission across a synapse usually requires neurotransmitters, because there is small space, the synaptic cleft, that separates one neuron from another.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
• C. Assertion is correct but Reason is incorrect.
• D. Assertion is incorrect but Reason is correct.

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

The incoming signal is transmitted when one neuron releases a neurotransmitter into the synaptic cleft which is detected by the second neuron through the activation of receptors placed opposite to the release site. Neurotransmitters are the chemicals used to transmit signals to the other neurons or non-neuronal cells (e.g., skeletal muscle, myocardium, pineal glandular cells) that they innervate.The chemical binding of the neurotransmitter to the receptors causes a series of physiological changes in the second neuron which constitutes the signal. Usually, the release from the first neuron (called presynaptic) is caused by a series of intracellular events evoked by a depolarization of its membrane, and almost invariably when an action potential takes place.