Dr . Nirajan Neupane MBBS IOM TUTH

Autonomic nervous system (ANS)

• Concerned with the motor innervations Involuntary structure i.e., smooth muscles , cardiac muscles & glands

• and fibers are General visceral efferent( GVE)

• Preganglionic neuron (B type fiber) : myelinated

• Postganglionic neuron(c type fiber) : mostly unmyelinated

Actions of sympathetic nervous system on different body parts

1. Cardiovascular system

-Increases heart rate ( HR), FOC -Vasocontriction ( except blood vessels of brain,heart, lungs & sk. muscles) -Increases BP

2. Respiratory system

-Increases RR, relaxes bronchial muscle ( bronchodilatation)

3. GI system -Decreases both the movement & secretion4. Exocrine Glands -Decreases secretions from all the glands except merocrine sweat gland ( in case of salivary gland viscosity increases) arrector pili muscle - erect5. Increases glucose production 6. Adrenal medulla : have lost their post ganglionic fibres -releases hormones

7. Pupil - dilates ( Mydriasis)

8.Urinary system

-relaxation of Detrussor muscle & constriction of urethral sphincter

9.Reproductive system - ejaculation of semen

- contraction of vagina/ uterus