Peripheral Nervous System

A. Sensory Receptors

B. Nerves Diagram

C. Regeneration of Nerve Fibers (cut or compressed axons)

  1. Separated ends seal off and swell
  2. Axon and myelin sheath (of injured site) disintegrates
  3. Schwann cells and macrophages migrate to site to phagocytize debris
  4. Neurilemma remains intact and schwann cells proliferate
  5. Axon "sprouts", guided by schwann cells, gap to original contact

D. Cranial Nerves (twelve pair) Diagram

Cranial Nerve I                    Olfactory  Smell
Cranial Nerve II                     Optic   Vision
Cranial Nerve III                  Oculomotor   Motor function (movement of eyelid and eyball) Sensory function (muscle sense)
Cranial Nerve IV                                  Trochlear  Motor function (movement of eyeball) Sensory function (muscle sense)
Cranial Nerve V  Trigeminal Motor function (chewing) Sensory function (touch, pain, and temperature)
Cranial Nerve VI                                   Abducens   Motor function (movement of eyeball) Sensory function (muscle sense)
Cranial Nerve VII Facial   Motor function (facial expression and secretion of saliva and tears) Sensory function (muscle sense )
Cranial Nerve VIII                          Vestibulocochlear Hearing and equilibrium
Cranial Nerve IX                          Glassopharyngeal  Motor function (secretion of saliva) Sensory function (taste)
Cranial Nerve X  Vagus  Motor function (smooth muscle contraction and relaxation and secretion of digestive fluids) Sensory function (muscle sense)
Cranial Nerve XI Accessory  Motor function (swallowing and head movements) Sensory function (muscle sense)
Cranial Nerve XII  Hypoglossal  Motor function (movement of tongue during speech and swallowing) Sensory function (muscle sense)

E. Spinal Nerves (31 pairs) Diagram

F. Reflex and Reflex Arc Diagram