Biology · Neural Control and Coordination · NEET
No. The human neural system has two parts: the central neural system (CNS) and the peripheral neural system (PNS). The CNS is only the brain and spinal cord. The PNS is separate - it is all the nerves of the body that are associated with the CNS. So the PNS connects TO the CNS but is not part of it.
The PNS nerve fibres are of two types. Afferent nerve fibres carry impulses from tissues and organs TO the CNS (sensory, going in). Efferent nerve fibres carry regulatory impulses FROM the CNS to the peripheral tissues and organs (motor, going out). Easy trick: Afferent = Arrive at CNS, Efferent = Exit the CNS.
The PNS is divided into two parts: the somatic neural system and the autonomic neural system. The somatic neural system relays impulses from the CNS to skeletal (voluntary) muscles. The autonomic neural system transmits impulses from the CNS to involuntary organs and smooth muscles.
The autonomic neural system is a division of the PNS, not the CNS. The autonomic neural system is further classified into the sympathetic neural system and the parasympathetic neural system. This is a common trap - students think 'autonomic' sounds central, but NCERT places it inside the PNS.
According to NCERT, the visceral nervous system is the part of the peripheral nervous system that comprises the whole complex of nerves, fibres, ganglia and plexuses. Through it, impulses travel from the CNS to the viscera (internal organs) and from the viscera back to the CNS.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
The PNS comprises all the nerves of the body that are associated with the CNS (the brain and spinal cord). Its nerve fibres are of two types: afferent fibres and efferent fibres.
The somatic neural system relays impulses from the CNS to skeletal muscles (voluntary movement). The autonomic neural system transmits impulses from the CNS to involuntary organs and smooth muscles of the body.
It is classified into the sympathetic neural system and the parasympathetic neural system, which usually act in opposite ways on the same organs.
NEET frequently asks classification-based questions (which part belongs to CNS vs PNS, afferent vs efferent). Knowing the exact NCERT tree - PNS to somatic and autonomic, autonomic to sympathetic and parasympathetic - lets you answer these one-mark questions instantly.
