Question

Which one of the following pairs of structures distinguishes a nerve cell from other types of cell?

• A. Flagellum and medullary sheath
• B. Nucleus and mitochondria
• C. Perikaryon and dendrites
• D. Vacuoles and fibres

Answer 1

The correct option is C Perikaryon and dendrites

Nerve cells have a cell body called the cyton or perikaryon. Dendrites and the axon arises from the perikaryon.

Dendrites are short, branched processes that receive impulses from an adjacent neuron and transfer them to the cyton (afferent processes) whereas the axon is a single, long process that conducts impulses from the cyton to an adjacent neuron (efferent process).

The cytoplasm of a neuron is called neuroplasm which contains a prominent cell nucleus and cell organelles such as the mitochondria. It also contains fine fibres called neurofibrils that play a role in transport of various substances within the neuroplasm.

The axons of some neurons are covered by a sheath called a medullary sheath or myelin sheath which prevents the leakage of impulses from the neuron.

Neurons are devoid of flagella and vacuoles.