The Nervous System: An Overview

• The nervous system is a complex network of nerves and cells, known as neurons, that transmit signals between different parts of the body.
• It essentially functions as the body’s electrical wiring.
• It is divided into two main components:
  1. Central (CNS)
  2. Peripheral (PNS)
• This system is fundamental to everything the body does, from sensing heat and light to controlling muscle movements.

Central Nervous System (CNS)

• These comprises the brain and spinal cord, acting as the processing center for system.
• It interprets incoming sensory information and issues instructions.

1. Brain

   • The brain is the most complex organ in the body.
   • It controls various functions, including thought, memory, emotion, touch, motor skills, vision, breathing, temperature regulation, and hunger.

2. Spinal Cord

   • The spinal cord is a long, thin, tubular structure made of nervous tissue and support cells that extend from the brain.
   • It connects the brain with the rest of the body, transmitting signals for movement, sensation, and reflex actions.

Peripheral Nervous System (PNS)

• The peripheral nervous system consists of the nerves and ganglia outside the brain and spinal cord.
• It connects the CNS to the rest of the body.
• The PNS is divided into two main parts:

1. Somatic

   • Controls voluntary movements.
   • Composed of nerves that connect the brain and spinal cord to muscles and sensory receptors in the skin.

2. Autonomic 

   • Controls involuntary body functions.
   • It is further divided into two subdivisions:
     1. Sympathetic Division: Prepares the body for stressful or emergency situations (“fight or flight”).
     2. Parasympathetic Division: Controls body processes during normal conditions (rest and digestion).

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