Question

In mammals, the autonomic system is composed of

• A. Sympathetic and parasympathetic nerves
• B. Cranial and spinal nerves
• C. Brain and spinal cord
• D. Medullated and non-medullated nerves

Answer 1

Answer: (A)

The nervous system is divided into two major divisions, central and peripheral nervous system.

The centrally located central nervous system includes brain and spinal cord. Peripheral nervous system includes all cranial and spinal nerves.

Peripheral nervous system is further divided into somatic and autonomous divisions. The autonomous nervous system has two divisions; sympathetic and parasympathetic divisions, which have opposite functions.

The nerve fibres are classified as myelinated and non myelinated fibres on the basis of presence or absence of myelin sheath. Myelinated fibres are present in the white matter of brain and spinal cord as well as in cranial and spinal nerves. Non-myelinated fibres are present in autonomous nerves system.