By Pharmacist Salwan Salem 8-11-2015

-Central nervous system (CNS)

- Peripheral nervous system (PNS)

*CNS: spinal cord and brain

*The PNS consists of:

sensory neurons running from stimulus receptors that inform the CNS of the stimuli

motor neurons running from the CNS to the muscles and glands - called effectors - that take action.

* PNS subdivided into :

Autonomic , and somatic

Autonomic NS :

- sympathatic neurons (thorasic and lumbar part of spinal cord)

- Parasympathatic neurons (cranial and sacral part of spinal cord)

1.Cardiovascular system :

-ve chronotropic effect

-ve inotropic effect

.Decrease SA and AV conductivity

.Increase IC Ca by phosphatidy inositol system

.Production of NO from arginine in endothelial cells

2. GIT:

Increase peristalsis , tone ,circulation , increase secretion , nausea and vomiting

3.Urinary tract :

Increase contraction of detrusor muscle of bladder

4. Eye miosis , and decrease IOP

5.Exocrine glands :

Increase secretion of lacrimal , salivary ,and digestive .

6.Respiratory system :

Bronchial constriction , tracheobronchial secretion

The Cranial Nerves

slowing down of the heartbeat

lowering of blood pressure

constriction of the pupils

increased blood flow to the skin and viscera

peristalsis of the GI tract

are neuron receptor that signal for muscular contractions . They are cholinergic receptors .

-NR found in :

1-NMJ

2-Autonomic ganglia

3-Adrenal medulla

4-ligand gated ion receptor

Nicotinic receptor agonist is nicotine .

NR Blocked by tubocurarine and doxacurium .

Types of MR:

M1 : in CNS , Gastric parietal cells

M2: heart

M3: exocrine gland , smooth muscle, bronchia ,bladder , sweat and salivary glands.

M4 and M5 : in CNS , but function not fully understood .

1.Cardiovascular system :

-ve chronotropic effect

-ve inotropic effect

.Decrease SA and AV conductivity

.Low dose … V.D and tachycardia

.Increase IC Ca by phosphatidy inositol system

Production of NO from arginine in endothelial cells

2. GIT:

Increase perstalsis , tone ,circulation , increase secretion , nausea and vomiting

3.Urinary tract :

Increase contraction of detrusor muscle of bladder

4. Eye miosis , and decrease IOP

5.Exocrine glands :

Increase secretion of lacrimal , salivary ,and digestive .

6.Respiratory system :

Bronchial constriction , tracheobronchial secretion

. Direct acting

. Indirect acting

A -Direct acting :

Cholinesters (esters of Ach ) carbacol , bethanicol .

Alkaloids

-rarely used

- S/E : produce miosis and decrease IOP

- Has profound effect on CVS and GIT due to ganglionic stimulating activity .

- Activate N receptors in adrenal medulla .

not Hydrolysed by AchE , while hydrolyzed by other esterases .

Used for treatment of bladder and GIT atony .

Alkaloids

Is Muscarinic agonist

Mainly used in opthalmology , caused miosis

S/E : sweating and salivation because enter CNS

Reversible AchE inhibitors and irreversible AchE inhibitors .

Reversible :

1- Physostigmine :

-Act on MR , N gang , and N NMJ

-uses : GIT , bladder atonty , and glucoma .

- S/E : bradycardia , convulsions .

2-Neostigmine

-Polar , so doesn’t pass BBB

-effect on skeletal muscle is greater than that of pysostigmine .

- used for Mysthemia Gravis , and antidote for tubocurarine .

3- Pyridostigmine :

-for long term management of M.G because of longer duration of action .

4- Edrophomium :

Used for diagnosis of M.G

-Has duration 10-12 min

- organophosphorous cpds / insectsides

- Isoflurophate

-Echothiophate

- clinically used for glucoma

Atropine

-causes : eye medryasis , and cycloplagia

-in low dose block M1R , cause bradycardia

-in high dose (>1 mg ) block M2R , cause tachycardia.

- dilate cutaneous vasculature

-No effect on arterial blood pressure .

-GIT: decrease motility and secretion

-urinary tract : reduce hyper motility of bladder

-secretions: decrease salivation , sweating , and lacrimal secretion .

-antispasmodic , antidote for anticholinergic , reduce secretion prior to surgery , and cause medriasis in ophthalmology.

-other anti Muscarinic :

Scopolamine : motion sickness

Pirenzepine : gastric ulcer reduce HCL

Ipratropium : bronchodilator used for asthma .

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