Autonomic nervous system

1. Autonomic nervous system By AYOTUNDE BAMKEFA (case study)

2. Outline • Introduction • Function • Clinical Correlation

3. Introduction • The nervous system is a network of specialized cells that helps the body react to changes in it’s external and internal environment, • Divided structurally into CNS and PNS • Divided functionally into SNS and ANS

5. Autonomic Nervous System • is also know as the visceral nervous system or the visceral motor system. • It controls the unconscious body functions such as heart rate , digestion ,breathing patterns etc. • ANS is further divided into sympathetic and parasympathetic systems. • A Third special division of the ANS is the Enteric nervous system(at times classified under PNS)

6. The pathways of the first two divisions of the ANS vary by • The location of the presynaptic cell bodies • The nerves that conduct the presynaptic fibers from the CNS.

7. Sympathetic Division • Also known as Thoracolumbar Division • Fight or flight response • Presynaptic cell bodies come from one location ;ACh • Postsynaptic cell bodies are found in two places; paravertebral and prevertebral ganglia ; noradrenaline

9. Parasympathetic Division • Also known as Crainosacral outflow • Response that returns the body to it’s regular state • Presynaptic cell bodies are located in two locations ;ACh • Postsynaptic cell bodies are found in the head, visceral cavities of the trunk and erectile tissue of the external genitalia ;ACh, NO2

11. Enteric Nervous System • This is a complex autonomic ganglia found in the walls of the stomach and small intestine. • Collected into two ganglia: myenteric (Auerbach’s) and submucosal (Meissner’s ) plexuses. • Neurotransmitters : ACh, substance P, 5HT, enkephaline.

14. Funtion • When Changes occur in the body(visceral), either as a result of factors from the external or internal environment, the autonomic nervous system instigates compensatory measures. • Meaning it regulates the reactions of the body(smooth and modified cardiac muscles ,secretory cells). • The next slide shows how the sympathetic and parasympathetic nervous system work together .

17. Clinical Corelation • Dysautonomia • There is an imbalance between the sympathetic and parasympathetic systems. • Symptoms include frequent , vague but disturbing aches and pains. Faintness, fatigue and inertia, severe anxiety attacks, tachycardia, hypotension, poor exercise tolerance, gastrointestinal symptoms, sweating, dizziness, blurred vision, numbness, tingling, anxiety and depression.

18. It could occur on it’s own or it could manifest in disorders like Marfan’s syndrome, Ehlers- Danlos syndrome, multiply system atrophy(shy- drager syndrome), people with joint hypermobility etc • Causes : viral illness, brain injury, genetic factors, pregnancy Maneuvers to counter it :crossing of legs in front or behind, squatting position and tying shoes position. 2. Pure autonomic failure(Bradbury-Eggleston syndrome) • A form of Dysautonomia that occurs Mid – life or latter in life, more common in men than women

19. Symptoms : dizziness, fainting(caused by orthostatic hypotension) ,neck pain, visual disturbance , chest pain, fatigue, sexual dysfunction • Cause : loss of cell of the IML Column, loss of catecholamine uptake. • Drugs : vasopressors (e.g. fludrocortisone) and compression

20. References • http://www.scholarpedia.org/article/Autonomic_nervous_system • http://www.americanheart.org/presenter.jhtml?identifier=4463 • http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/PNS.html • http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/PNS.html • http://greenfield.fortunecity.com/rattler/46/autonomic.htm • Clinical Anatomy, Keith Moore • http://en.wikipedia.org/wiki/Pure_autonomic_failure