Question

Of the following, which is the only structure that is in the PNS, as opposed to the CNS?

(a) a tract

(b) white matter

(c) a ganglion

(d) gray matter

(e) a neuron

Answer 1

Central Nervous system involves brain and spinal cord. Peripheral nervous system involves sensory receptors,sensory neurons and motor neurons.

An axon of a neuron is called nerve fibre. The bundles of nerve fibres found in the CNS are referred to as NERVE TRACTS. While the bundles of nerve fibres in PNS are called peripheral nerves. Peripheral nerves comprise 12 pairs of cranial nerves and 31 pairs of spinal nerves.

White matter and Gray matter are parts of Central nervous system. These are not found in PNS.

Ganglia are the collection of nerve cell bodies outside the CNS. They are part of PNS , not CNS. The collection of cell bodies inside CNS are called nuclei.

Neurons are found in both PNS and CNS. They are of two types: sensory neurons (carry impulses from the receptor organs to the CNS) AND motor neurons (transmit impulses from CNS to the muscles and glands).

Answer is Ganglion.