Question

Select the correct match from the following options.

• A. Nissl's granules - Found in axon.
• B. Non-myelinated neurons of peripheral nervous system - Schwann cells present but do not secrete myelin sheath.
• C. Unipolar neuron - Possess 1 dendrite.
• D. Sodium - potassium pump - Transports 2K⁺ into the intracellular fluid.

Answer 1

Answer: (B)

Nissl's granules: Nissl's granules are large granular bodies found in the cyton of nerve cells. They are made of granular endoplasmic reticulum and ribosomes that occurs in nerve cell bodies and dendrites. They play an important role in protein synthesis.
Myelinated nerve fibres: The myelinated nerve fibres are enveloped with Schwann cells that form a myelin sheath around the axon. Nodes of Ranvier (gaps between two adjacent myelin sheaths) present.
Examples: Found in spinal and cranial nerves.
Non-myelinated nerve fibres: Unmyelinated nerve fibres are enveloped with Schwann cells that do not form a myelin sheath around the axon. Nodes of Ranvier is absent.
Examples: Commonly found in autonomous and somatic neural systems.
Unipolar neuron: These neurons possess 1 axon but no dendrite. Example - Neurons in the embryonic stage.
$N{a}^{+}-K^{+}$ pump: These ionic gradients across the resting membrane are maintained by the $N{a}^{+}-K^{+}$ pump which actively transports $3N{a}^{+}$ outwards for $2K^{+}$ into the cell.