Autonomic Pharmacology (cardiac output, blood flow distribution, digestion) (Chapter 6, Basic and Clinical Pharmacology, 13th edition, Lange publication)- 1. Sympathetic (thoracolumbar) division
- Most preganglionic Fibers are short and end in paravertebral chains. The other preganglionic fiber end in pre vertebral ganglia
- 2. Parasympathetic (carniosacral) division
- CN 3, 7, 9, 10
- 3rd, and 4th Sacral Spinal Nerve Roots
- Preganglionic fibers end mostly in the target organs, however, in following cases ganglia are located near target organ with separate ganglia
- Ciliary Ganglia
- Pterygopalatine ganglia
- Submandibular ganglia
- Otic ganglia
- Pelvic Ganglia
- 3. Enteric Nervous System (ENS)
- sometimes described as 3rd division of ANS
- extends from esophagus to distal colon
- both motor and sensory activities are seen
- receives preganglionic parasympathetic fibers, and postganglionic sympathetic fibers. These have modulatory effect.
- ENS functions in semi-autonomous manner. Uses ANS input for modulation of GI activity, and sends back sensory fibers back to the CNS.
- Includes
- Myenteric Plexus (The Plexus of Auerbach)
- Submucous Plexus (The Plexus of Meissner)
- Autonomic Receptors
- Cholinoreceptors (Muscarinic and Nicotinic)
- Adrenoreceptors
- Alpha 1
- Alpha 2
- Beta 1
- Beta 2
- Beta 3
- Dopamine Receptors
Cholinomimetic Drugs- Direct Acting Cholinominetic Agents
- directly bind to the autonomic receptors (Muscarinic, and Nicotinic)
- Types:
- Choline Esters (Acetylcholine, Methacholine, Cabachol, Bethanechol)
- Alkaloids (
- Indirect-acting Cholinomimetic Agents
- inhibits acetylcholinesterase, increasing endogenous Ach concentration
- thus are amplifiers of endogenous Ach
- Types
- Alcohols (Edrophonium)
- Carbamates and related agents (Neostigmine, Pyridostigmine, Physostigmine)
- Organophosphates (Echothiophate)
- Clinical Uses
- The Eye
- Glaucoma
- Acute-angle-closure glaucoma
- GI and Urinary Tract
- Post-operative Ileus
- Congenital Megacolon
- Urinary Retention
- Neuromuscular Junction
- Heart
- Antimuscuarinic Drug Intoxication
- Central Nervous System
- Toxicity
- Direct-Acting Muscarinic Stimulants
- Direct-Acting Nicotinic Stimulants
- Cholinersterase Inhibitors
|
|