CH 13

• Function of NS: Motor function-

  stimulates muscle cell contraction and gland secretion; Function of PNS

  Ex: smooth, skeletal and cardiac muscles
• Sensory Function

  detection of sensations in and outside of body; function of PNS

  Ex: special senses and visceral organs
• Integrative Function

  decision-making processes; Function of CNS

  -interpretation of sensory info

  -planning and monitoring movement

  -maintenance of homeostasis

  -higher mental functions such as language and learning
• Brain

  -Soft white, gray organ

  -indirectly or directly controls most of the body's functions

  -anatomically continuous with spinal cord; resides in the cranial cavity
• Brain has 4 divisions

  Each distinct type of input received and where output is sent

  -Cerebrum

  -Diencephalon

  -Cerebellum

  -Brainstem
• Cerebrum

  -performs higher mental functions

  -interpret sensory info

  -plan and initiate movement
• Diencephalon

  -processes, integrates, and relays info

  -maintain homeostasis

  -regulates biological rhythms
• Cerebellum


  monitor and coordinates movement
• Brainstem

  -maintain homeostasis

  -controls some reflexes

  -monitors movement

  -integrates and relays info
• Spinal Cord

  -long, tubular organ enclosed within protective vertebral cavity

  -blends with inferior portion of brainstem; ends between first and second lumbar vertebrae
• White matter

  -consists of myelinated axons for conduction of action potentials

  Brain: tracts and fibers

  Spinal cord: tracts
• Gray matter

  -consists of dendrites and unmyelinated axons

  Brain: cerebral cortex and basal nuclei

  Spinal Cord: horns
• Spinal white matter is superficial while it is deep in brain.
• 5 lobes found in each hemisphere of cerebrum

  -frontal

  -parietal

  -temporal

  -occipital

  -insula
• Gray matter: cerebral cortex


  functionally most complex part of cortex; covers underlying cerebral hemispheres

  • all neurons in cortex are interneurons
  • functions: revolve around conscious processes (planning movement, interpreting incoming sensory info, and complex higher functions)