Question

In a neuron, conversion of electrical signal to a chemical signal occurs at
A. Cell body
B. Axonal ends
C. Dendritic end
D. Axon

Answer 1

Hint: The neuron is the basic working unit of the brain, a specialized cell designed to transmit information to other nerve cells. Neurons are cells within the nervous system that transmit information to other nerve cells, muscle, or gland cells. Most neurons have a cell body, an axon, and dendrites. They are responsible for carrying information throughout the human body. Using electrical and chemical signals, they help coordinate all of the necessary functions of life.

Complete answer:
(A) Cell Body: The cell body, also called the soma, is the spherical part of the neuron that contains the nucleus. The cell body connects to the dendrites, which bring information to the neuron, and the axon, which sends information to other neurons. When information is received from another neuron, the dendrites pass the signal to the cell body. The cell body then may send the information to the axon, depending on the strength of the signal. The job of the cell body is to control all of the functions of the cell. It contains several important organelles that help it do this. So, "A" is not the correct answer.

(B) Axonal end: The swollen end of a telodendron is known as the axon terminal which joins the dendron or cell body of another neuron forming a synaptic connection. Axons make contact with other cells—usually other neurons but sometimes muscle or gland cells—at junctions called synapses. The axonal terminals are specialized to release the neurotransmitters 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. A nerve impulse travels in a form of electrical charge from a neuronal axon end to the synapse. Here, the electrical impulse is converted to the chemical impulse in the synaptic cleft. Thus, the impulse always flows from one axonal end of a neuron to another dendron head of a neuron. Therefore, conversion of electrical signal to a chemical signal occurs at the Axonal end. So, "B" is the correct answer.

(C) Dendritic end: Dendrites are tree-like extensions at the beginning of a neuron that help increase the surface area of the cell body. These tiny protrusions receive information from other neurons and transmit electrical stimulation to the soma. Dendrites are also covered with synapses. Most neurons have multiple dendrites, which extend out-ward from the cell body and are specialized to receive chemical signals from the axon termini of other neurons. Dendrites convert these signals into small electric impulses and transmit them inward, in the direction of the cell body. So, "C" is not the correct answer.
(D) Axon: Axon, also called nerve fibre, a portion of a nerve cell (neuron) that carries nerve impulses away from the cell body. A neuron typically has one axon that connects it with other neurons or with muscle or gland cells. Some axons may be quite long, reaching, for example, from the spinal cord down to a toe. These specialized projections called axons allow neurons to transmit electrical and chemical signals to other cells. Neurons can also receive these signals through root-like extensions known as dendrites. So, "D" is not the correct answer.

Hence, the correct answer is option (B).

Additional information:
About Components of the Neuron, neurons are made up of three major parts: a cell body, or soma, which contains the nucleus of the cell and keeps the cell alive; a branching treelike fibre known as the dendrite, which collects information from other cells and sends the information to the soma; and a long, segmented fibre known as the axon, which transmits information away from the cell body toward other neurons or to the muscles and glands.

Note: The dendrites receive neuron signals, and axons transmit them. Most neurons have a lot of dendrites and only have one axon. An axon can divide into many branches called telodendria At the end of each telodendron is an axon terminal. Axon terminals contain synaptic vesicles that store the neurotransmitter for release at the synapse.