NERVOUS SYSTEM

• Functions of Nervous System


  • Sensory input
  • Integration
  • Motor input
• Sensory input


  Gathering information to monitor changes occurring inside and outside the body
• Integration


  To process and interpret sensory input and decide if action is needed
• Motor output


  A response to integrated stimuli that activates muscles or glands
• Structural classification of Central Nervous System


  • Brain
  • Spinal cord
• Structural classification of Peripheral Nervous System


  • Cranial nerves
  • Spinal nerves
• Sensory division (afferent)


  Nerve fibers that carry information to the central nervous system
• Motor division (efferent)


  Nerve fibers that carry impulses away from the central nervous system
• Subdivisions of motor division

  • Somatic nervous system
  • Autonomic nervous system
• Subdivisions of autonomic nervous system


  • Sympathetic nervous system
  • Parasympathetic nervous system
• Somatic nervous system


  Controls voluntary muscles
• Autonomic nervous system


  Controls involuntary glands
• Sympathetic nervous system


  Also known as thoraco-lumbar division
• Parasympathetic nervous system


  Also known as cranio-sacral division
• Parasympathetic: Digestive system


  Increases peristalsis and secretion by digestive glands; relaxes sphincters
• Sympathetic: Digestive system


  Decreases activity of digestive system; constricts sphincters
• Parasympathetic: Liver


  No effect
• Sympathetic: Liver


  Causes glucose to be released to blood
• Parasympathetic: Lungs


  Constricts bronchioles
• Sympathetic: Lungs


  Dilates bronchioles
• Parasympathetic: Urinary bladder/urethra


  Relaxes sphincter
• Sympathetic: Urinary bladder/urethra


  Constricts sphincter
• Parasympathetic: Kidneys


  No effects
• Sympathetic: Kidneys


  Decreases urine output
• Parasympathetic: Heart


  Decreases rate, slows and steadies
• Sympathetic: Heart


  Increases rate, force of contraction
• Parasympathetic: Blood vessels


  No effect on most blood vessels
• Sympathetic: Blood vessels


  Constricts blood vessels in viscera; increases BP
• Parasympathetic: Salivary and lacrimal glands


  Stimulates; increases production of saliva and tears
• Sympathetic: Salivary and lacrimal glands


  Inhibits; results in dry mouth and dry eyes
• Parasympathetic: Eye (iris)


  Stimulates constrictor muscle; constricts
• Parasympathetic: Penis


  Causes erection
• Sympathetic: Penis


  Causes ejaculation
• Interneurons (association neurons)


  Found in neural pathways in the central nervous system; 99% of neurons in body; connect sensory and motor neurons
• Parasympathetic nervous system


  Relaxing and digesting system
• Sympathetic nervous system


  Fight or flight system
• Neuron (nerve cell)


  Functional unit
• Cell body (soma)


  The dark spots inside the nucleus
• Nissl substance


  Spots on cell body
• Mitochondria


  Releases adenosine triphosphate (ATP)