INTRODUCCION A LA FARMACOLOGIA DEL SISTEMA NERVIOSO AUTONOMO SNA

Pharmacology of the Autonomic Nervous System

This section discusses the pharmacology of the autonomic nervous system, including its components, neurotransmitters, receptors, and effects.

Components of the Autonomic Nervous System

• The autonomic nervous system regulates involuntary responses in smooth muscle and glandular tissue. It consists of the sympathetic and parasympathetic systems.

• Both systems comprise a pre-ganglionic neuron and a post-ganglionic neuron.

• Sympathetic neurons release catecholamines (adrenaline, noradrenaline, dopamine), while parasympathetic neurons release acetylcholine.

Neurotransmitters and Receptors

• Sympathetic system uses alpha and beta receptors; parasympathetic system uses nicotinic and muscarinic receptors.

• Different receptor subtypes exist within each system, influencing specific responses in various organs.

Effects of Catecholamines on Receptors

• Catecholamines act on adrenergic receptors causing specific responses like vasoconstriction or relaxation in different tissues.

• Adrenergic receptors can desensitize with prolonged activation, reducing their effectiveness over time.

Synthesis and Release of Acetylcholine

• Acetylcholine is synthesized by choline acetyltransferase from choline and acetyl coenzyme A in cholinergic neurons.

• Stored acetylcholine is released into the synaptic cleft upon calcium influx through voltage-dependent channels.

New Section

Explanation of muscarinic and nicotinic receptors, their types, locations, and effects.

Muscarinic Receptors

• Muscarinic receptors interact with proteins.

• There are five types of muscarinic receptors that trigger various responses.

• M1 receptor in the autonomic ganglion causes excitatory postsynaptic potential.

• M2 receptor in the heart slows down spontaneous depolarization.

New Section

Details on the effects of different subtypes of muscarinic receptors.

Effects of Muscarinic Receptor Subtypes

• M1 receptor in the autonomic ganglion leads to excitation and varied effects in the central nervous system.

• M2 receptor in the heart causes slowing of spontaneous depolarization and hyperpolarization.

New Section

Further exploration of muscarinic receptor subtypes and their effects.

More on Muscarinic Receptor Subtypes

• M3 receptor in smooth muscle induces contractions and gland stimulation.