The nervous system

The nervous system

1. It is divided into the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).

   • CNS: consists of the brain and the spinal cord. This is where all the complex processing of information is done and decisions are made.
   • PNS: consists of the ganglion and nerves. It brings information from the CNS and transmits this information to the muscles and glands.

2. The organisation of the human nervous sytem

   • Human nervous system
     • Peripheral central nervous sytem
       • Autonomic nervous system
         • Sympathetic nervous system
         • Parasympathetic nervous system
       • Somatic nervous system
     • Central nervous system
       • Brain
         • Central hemisphere
         • Cerebellum
         • Brain stem
       • Spinal cord

3. The brain is the center of awareness. It is divided into two hemispheres. The cortex is more developed in humans than in all other animals.

4. The spinal cord is an extension of the brain. It transports messages to and from the brain to the peripheral nervous system. It is also responsible for reflexes.

5. The parts of the brain are: the frontal lobe, the parietal lobe, the occipital lobe, the temporal lobe, the spinal cord and the cerebellum.

6. Somatic Nervous System (SNS): receives information from the senses and transmits it to the CNS. It also transmits information from the CNS to direct movement of muscles.

7. Autonomic Nervous System (ANS): responsible for vital functions such as heart beat, breathing, digestion. It transmits information to and from the internal body organs such as the liver and the lungs. It operates automatically, involuntarily.

8. The sympathetic nervous system stimulates function like digestion. It is involved in 'the fight or flight response'.

   • to make homeostasis.

9. The parasympathetic nervous system slows functions like digestion. It is involved in 'the fight or flight response'.

   • The two systems interact

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