Nervous System

Nervous System

1. Central Nervous System- brain and spinal cord

   • Spinal cord- within the spinal column that communicates with all sensory organs and muscles
     • Dorsal roots- enter the spinal cord, carrying sensory information
       • at the back, away from the stomach
       • Dorsal root ganglia- the cell body of the sensory neurons are in clusters of neurons outside the spinal cord
     • Ventral roots- exit the spinal cord, carrying motor information
       • at the front, towards the stomach

2. Peripheral Nervous System- connects the CNS to the rest of the body

   • Somatic Nervous System- consists of the axons conveying messages from the sensory organs to the CNS and from the muscles to the CNS
   • Autonomic Nervous System- controls the heart, intestines, and other organs. Prepares the body for vigorous activity. Consists of gnaglia just to the left and right of the spinal cords central regions.
     • Sympathetic Nervous System- prepares organs for 'flight or fight'.
       • increased breathing and heart rate, decreased digestive activity
     • Parasympathetic Nervous System- restores organs to nonemergancy status
       • decreased heart rate and breathing, increases digestive activity