Question

Electrical impulse travels in a neuron from -
(a)Dendrite - axon - axonal end - cell body
(b)Cell body - dendrite - axon - axonal end
(c)Dendrite - cell body - axon - axonal end
(d)Axonal end - axon - cell body - dendrite

Answer 1

Hint Electrical impulse occurs on the neuron in the body due to a phenomenon that occurs across the plasma membrane of the cell. Neurotransmitters transfer from an axon to a dendrite through a synapse. The parts of a neuron on the order from top to bottom are the cell body, nucleus, axon, and axonal terminal.

Complete answer:
- An electrical impulse or nerve impulse is an electrical phenomenon that occurs due to a difference in electrical charge across the plasma membrane of the neuron.
- Neurons carry these impulses from one place to another by connecting receptors to the central nervous system. They also connect one part of the nervous system to another in the case of the brain and the spinal cord and effector organs such as muscles and glands.
- The structure of the neuron is as follows: It starts with the dendrite, which leads to the cell body, leading to the axon, and finally the axon terminal, which connects to the dendrite of the other neuron through a synapse. Hence, the electrical impulse travels from the dendrite, cell body, axon, to the axonal end.

Additional Information:
- A nerve impulse is also known as an action potential. It speeds along the axon in approx seven milliseconds.
- The axon is insulated with a myelin sheath which is a lipid layer and allows the electrical signal to travel much more rapidly.
- There are small gaps in the myelin sheaths known as nodes of Ranvier that expose the axon that help in faster transmission of a signal.

So, the correct answer is ‘Dendrite - cell body - axon - axonal end’.

Note: - When a neuron is not actively transmitting an electrical impulse, it remains in a resting state.
- When transmitting an impulse, the axon does not directly touch the dendrite. There is a small gap between the two cells, known as a synaptic cleft.