Question

Schwann cells and nodes of Ranvier are found in
A. Neurons
B. Chondroblasts
C. Osteoblasts
D. Gland cells

Answer 1

Hint: It is the basic working unit of the brain, which are specialized and are designed to transmit some impulses to other cells. These cells are divided into three parts; cell body, an axon, and dendrites. They have a glial cell that is separated by gaps known as nodes of Ranvier.

Complete answer:
Nodes of Ranvier are microscopic gaps found between myelinated axons. They help to speed up the propagation of action potentials along the axon via saltatory conduction. They are periodic gaps present on the axons of neurons and are insulated by the myelin sheath and it helps in the rapid conduction of nerve impulses. In the peripheral nervous system, Schwann cells synthesize myelin sheaths around the neuronal axon.

The myelin sheath consists of myelin. They are a type of glial cells that help in keeping myelinated and unmyelinated nerve fibres alive. The sheath made by Schwann cells is not continuous. They are derived from neural crest cells. Various neurotrophic factors help in the regulation of Schwann cells. A nerve cell transmits impulses in the form of chemical or electrical signals. A nerve cell possesses dendrites, cell body or soma, axon hillock, axon and the terminal buds. The terminal end of the neuron has vacuoles that consist of neurotransmitters.

Hence, the correct answer is option A.

Note: In vertebrates, the action potential travels along the myelin-coated axons which are regenerated at the nodes of Ranvier that lacks myelination and are identified by the tight junctions between the axons and the glial cells. Specific proteins are enriched in this region of the nodes.