Biology

The Human Brain

The brain of all vertebrates develops from three swellings at the anterior end of the neural canal of the embryo. From front to back these develop into the

• forebrain (also known as the prosencephalon)
• midbrain (mesencephalon)
• hindbrain (rhombencephalon)

The brain receives nerve impulses from

• the spinal cord and
• 12 pairs of cranial nerves
  • Some of the cranial nerves are "mixed", containing both sensory and motor axons
  • Some, e.g., the optic and olfactory nerves (numbers I and II) contain sensory axons only
  • Some, e.g. number III that controls eyeball muscles, contain motor axons only.

edit @ 19 Jan 2009 21:23:08 by Dhachdanai