Introduction to the ANS

Question 1

Why the ANS and pharmacology

Answer 1

1.We are interested in the receptors ,so that we can mimic ANS by creating drugs that can block the SNS / PSNS .Also predict adverse MOA

Question 2

SNS receptors

Answer 2

alpha 1 &2

beta 1&2

Question 3

PSNS end organ innovation

Answer 3

Cranial nerves 3,7,9,10

Organs innovated :
heart (SA and AV node) ,lungs(bronchioles > mucous production and bronchoconstriction ),stomach ,interstines ,bladder(Urinary tract > causes the sphincter to relax and bladder contraction to pee and for penile erection ) ,pancreases(GIT ,colon , enteric NS ,myenteric plexus > increase motility and secretion ) ,eyes (pupilary muscle , the circulatory muscle > to cntrol the amount of light entering the eye > miosis

Question 4

How is the PSNS mimicked ?

Answer 4

By inhibiting the action of acetylcholine esterase inhibitors

Question 5

Types of acetylcholine esterase inhibitors

Answer 5

1. Reversiable
   * neostigmine eg pyridostigmine and endrophonium
2. Irreversible
   * Malathion eg organophosphates pesticides

Question 6

Irreversible ACh-esterase inhibitors

Answer 6

Malathion is very potent and it is usually ingested by farm workers by mistake 
>Symptoms of malathion 
*salivation 
*bradycardia 
*sweating 
*bronchoconstriction 
*mucous production

Question 7

Uses of ACh-esterase inhibitors

Answer 7

Myasthenia gravis
This is disease in the skeletal muscles causing a reduction in the function of nicotinic receptors

treatment : neostigmine
diagnosis : edrophonium

2. Alzheimers disease
   result from reduction of ACh levels in the brain especially frontal cortex

Treatment ( by increaseing the level of Ach levels in the brain ): donepezil and rivastigmine Can be used for 18 months to 2 years

Question 8

PSNS blockers ( post ganglionic muscarinic receptors )- anti cholinergic side effects

Answer 8

Caused by atropine :
dry mouth 
tachycardia'
constipation 
blurred vision 
urine retention

Question 9

Use of PSNS blockers -atropine (muscuranic receptors) or hyoscine

Answer 9

*accidental ingestion of malathion
*bradycardia
*irritable bowel syndrome
diarrhea
*Broncho vasoconstriction
*pesticide toxicity