THE NERVOUS SYSTEM

1.     Nervous system:
      -    ensures the whole body responds appropriately
      -     to external conditions.

2.     Human nervous system can be divided into 2 parts:
      -     central nervous system (CNS)
      -     peripheral nervous system(PNS).
3.      CNS is:
      -     divided into somatic + autonomic nervous system.
      -     made up of brain + spinal cord,
4.      PNS is:
      -     made up of paired cranian + spinal nerves.












5.      Brain is:
      -     made up of grey matter (located in the outer cortex) + white matter (inside brain)
      -     divided into 3 regions: forebrain, midbrain, hindbrain.

6.      PNS has 2 sets of neurons: sensory + motor neurones.

7.      Motor neurones are divided into: somatic + autonomic nervous system.
8.     Divisions of the autonomic nervous system are distinguished by where the  nerves originate.
9.    Nerves of the sympathetic nervous system emerge from:
      -     upper + central spinal cord regions
      -     thoracic regions
      -     lumbar regions.
10.  Nerves of the parasympathetic nerves system originate from:
      -      cranial nerves
      -     sacral region of the spinal cord.
11.  Autonomic nervous system:
      -     controls the involuntary activities
      -     of the internal organs.












12.  Parasympathetic nervous system:
      -     maintains the normal functioning of the body
      -     in a non-threatening situation
      -     helps keep the body in a relaxed + unstressed condition.
13.  Sympathetic nervous system:
      -     brings about physiological responses
      -     to threatening situations.










14.  A neurone:
      -      nerve cell:
      -     which conveys information
      -     in the form of nerve impulses
      -     basic functional unit of the nervous system.
15.  There are 3 types of neurones:
      -      motor,
      -     sensory
      -     interneurones.

16.  Motor neurones - carry impulses - from the CNSà to effectors.
17.  Sensory neurones - carry impulses - from sensory receptors à to the CNS.
18.  Interneurones - relay impulses - between sensory + motor neurones.