Peripheral Nervous System and Autonomic Nervous System

Cranial Nerves  12 pair  Located on undersurface of brain and brain stem  Conduct impulses between brain and structures in head, neck, thoracic and abdominal cavities  Table 9.2

Spinal Nerves  31 pair attached to spinal cord  Named according to vertebrae location  Conduct impulses between spinal cord and other parts of body  Dermatomes – skin map, fig. 9-22

Peripheral Never Disorders  Neuritis – inflammation of peripheral nerves  Neuralgia – nerve pain Sciatica –largest nerve in body Trigeminal neuralgia – 5 th cranial nerve, jaw pain Bell’s palsy – 7 th cranial nerve, paralysis of facial features Herpes zoster – shingles, affects single dermatome

Autonomic Nervous System  Regulates involuntary function of cardiac and smooth muscle and grandular epithelial tissue to maintain or restore homeostasis  Broken into 2 divisions Sympathetic Parasympathetic

Sympathetic Nervous System  Thoracic and upper lumbar region  Function: emergency system, stress and exercise, prepares body for strenuous work, Fight or Flight  Figure 9-24

Parasympathetic Nervous System  Sacral and brain stem  Usually affect only 1 organ at a time  Controls visceral function under normal conditions

Disorders of Autonomic System  Usually stress induced Heart disease, hypertension Digestive problems  Colitis – inflammation of colon  Gastric ulcers Reduced resistance to disease  Leads to increase risk of infection and cancer Neuroblastoma – malignant tumor of Sympathetic Nervous System