Autonomic Pharmacology Flashcards
Autonomic Nervous system (ANS)
Visceral motor (involuntary)
Conducts impulses from the CNS to cardiac muscles, smooth muscles and glands
What divisions are under ANS?
Sympathetic
Parasympathetic
Sympathetic division (adrenergic)
Mobilizes body systems during activity (fight or flight)
NT: Noradrenaline
Parasympathetic divison (cholinergic)
Conserves energy (rest and digest)
Promotoes housekeeping functions during rest
CT: acetyl choline
Neurohumoral transmission
Transmission of impulse by nerve and chemical substance across synapse and neuro effector junction
“Transmitting an impulse”
What substances are passed during neurohumoral transmission and to where?
Acetylcholine and noradrenaline secreted and pass communcation from pregang nerve to postgang nerve to effector organ
Neurotransmitter characteristics
- Substance concentration should be increased @ synapse
- Characterized pharmacologically
- Exogenous admin should produce identical reactions
- Synthesized, stored and released when nerve stimulated and metabolized after release
Sequence of physiological events
- Axonal conduction
- NT release (to synapse)
- Receptor events (binding)
- Catabolism of NT (remaining inactivated)
Axonal Conduction
- Resting: membrane potential @ -85 mv due to leaking K+
- Increase of Na+ into cell changing voltage to 0 mv –> depolarization
NT release
NT reaches terminal of nerve –> Ca++ entry to axon –> NT release from vesicles (storage)
Process called EXOCYTOSIS
Receptor events
NT released @ synaptic cleft –> transmittd substance interacts with the receptors on effetor cell –> excitation or inhibition
Catabolism of NT
Duration of action limited by enzymes
Noradrenaline catabolized inta and extraneuronally
Acetyl cholin hydrolyzed by AchE
