Nervous System

• Interneurons are located within the brain and spinal cord and connect different parts of the nervous system to process and integrate information.
• fast communication is achieved by means of electrical signals, also known as

  nerve impulses
• electrical signals are carried by specialized cells called

  neurons
• major components of the nervous system

  1. brain
  2. spinal cord
  3. nerves
• • enclosed and protected in the cranium
  • central processing center
  • receives info, makes decision, coordinates body response

  brain
• functions as communication gateway between brain, trunk, and limbs

  spinal cord
• • cordlike structures
  • conduct information similar to electricity-conducting wires

  nerves
• nerves are composed of

  axons of neurons
• axons are cells bodies which are clustered in knot-like structures called

  ganglia
• ganglia serve as

  relay centers
• what makes up the central nervous system

  brain and spinal cord
• what constitutes the peripheral nervous system

  nerves and ganglia
• 2 types of nerve fiber

  sensory and motor
• carry sensory information from sensory receptors to the central nervous system

  sensory nerve fibers
• conduct motor instructions from the central nervous system to effector organs - the muscles and glands

  motor nerves
• both contain motor and sensory nerves

  mixed nerves
• 2 major group of nerves

  cranial and spinal nerves
• also communicates with internal organs

  vagus nerve (cranial nerve 10)
• spinal nerves communicate with the brain via

  spinal cord
• all spinal nerves are mixed nerves

  true
• 2 divisions of peripheral nervous system

  somatic and visceral subdivisions
• somatic nervous system includes sensory nerves from the

  1. skin
  2. muscles
  3. bones
  4. joints
  5. motor nerves that innervate skeletal muscles
• somatic nervous system controls

  1. voluntary muscle contractions
  2. involuntary somatic reflexes
• visceral nervous system includes

  1. sensory division that detects changes in viscera - organs in thoracic and abdominal cavities
  2. motor division that controls cardiac muscle, smooth muscle of internal organs and glands
• visceral nervous system is also known as

  autonomic nervous system