Autonomic Pharmacology

Nota:

• it is involuntary control. Dual innervations and it reacts with both sympathetic and parasympathetic actions oppose to each other.

1. Autonomic Nervous Systems

   Nota:

   • It innervates visceral organs. It's action can be sympathetic or parasympathetic. Parasympathetic activity dominates rest and digest while the sympathetic ones is meant for fight or flight.
   1. Comparison

      Nota:

      • The autonomic system are connected with the CNS via 2 neurone arranged in series with peripheral ganglia It is involuntary and the sympathetic and parasympathetic  nerves that belong to sensory (afferent) and motor (efferent) overlaps. Properties of smooth muscles include intercellular bridges hence it can be amplified and depolarized.
      1. Sympathetic and Parasympathetic

         Nota:

         • Preganglionic fibres: short in sympathetic and long in parasympathetic Postganglionic Fibres: long in sympathetic and short in parasympathetic Transmitter at ganglion: ACh for both Transmitter at organs: At sympathetic, NE, NA and ACh and dopamine, For parasympathetic, only ACh
   2. Features

      Nota:

      • Parasympathetic ganglia are close to the organs. While the sympathetic nerves ganglia are close to the spinal column. All of the ANS neural system requires Acetylcholine to function, however, the sympathetic system that innervates the heart uses adrenaline and noradrenaline at the muscular neural junction. It produces about 85% Adrenaline and 15% noradrenaline.
   3. Antagonistic Control

      Nota:

      • Internal organs are under antagonistic control one branch is inhibitory and one is excitatory. With the exception of sweat glands and the smooth muscle in most blood vessels.
2. Cholinergic Transmission

   Nota:

   • Cholinergic referes to the neuron or axon that is capable of releasing neurotransmitter, ACh when a nerve impulse passes. System includes: The entire Parasympathetic nervous System. Preganglionic neurons of the sympathetic nervous systems Somatic motor neuron CNS
   1. ACh

      Nota:

      • Positively charged quaternary ammonium group. It also have an ester group and easily hydrolysed IT is not selective for receptor subtypes. It has at ganglia and neuromuscular junction, it stimulates nicotinic receptors. At parasympathetic junctions, it stimulates muscarinic receptors.
3. Adrenergic

   Nota:

   • Release adrenaline. Synthesized from Tyroxine