Question

nervous system could be described as cns and pns or somatic and autom atic nervous system.

explain the terms and major organs that make these systems

Answer 1

Classification of nervous system:

The nervous system is divided into central nervous system and peripheral nervous system. The peripheral nervous system can be further divided into somatic nervous system and autonomic nervous system. The autonomic nervous system has two divisions-sympathetic and parasympathetic division.

Central nervous system:

The CNS lies along the central axis of the body. It consists of the brain and the spinal cord. It is the site of processing of the information. On the basis of the evaluation of the sensory information, the central nervous system responds accordingly and controls the body.

Peripheral nervous system:

The PNS lies along the peripheries of the body. It comprises of all the nerves of the body associated with the central nervous system (brain and spinal cord). The nerves are the components of the peripheral nervous system. The nerve fibres of the PNS are of two types: afferent fibres and efferent fibers.

The peripheral nervous system is divided into two divisions.

Somatic nervous system:

It relays impulses from the CNS to the skeletal (voluntary) muscles of the body. The somatic neural system consists of efferent fibres that transmit the regulatory impulses from the central nervous system to the concerned skeletal muscle of the body.

Autonomic nervous system:

It transmits the impulse from the central nervous system to the involuntary organs, smooth muscles of the alimentary canal, reproductive tract, blood vessels. The autonomic nervous system consists of efferent fibres that transmit the regulatory impulses from the CNS to the concerned involuntary organ, muscle, gland of the body.

The autonomic nervous system is further classified into two subtypes: Sympathetic nervous system, Parasympathetic nervous system.

The sympathetic and parasympathetic neural systems have antagonistic effects on the organs. This is because of the different nature of the neurotransmitters released by the axons of the sympathetic and parasympathetic neural system.