The autonomic nervous system has two main divisions - the sympathetic and parasympathetic systems. It uses two major neurotransmitters - norepinephrine (NE) which is the primary transmitter at sympathetic postganglionic neurons, and acetylcholine (ACh) which is used by parasympathetic neurons. There are several steps involved in the synthesis, storage, release, action, and degradation of these neurotransmitters. Pharmacological targets for drugs include adrenoceptors and cholinergic receptors to modulate the effects of NE and ACh in the autonomic nervous system.
5. NE primary transmitter at sympathetic post
ganglionic neuron effector cell synapses
EXCEPTIONS
sympathetic fibers to sweat glands
Vasodilator sympathetic fibers to skeletal muscles
6.
7. Synthesis, Strorage and Release of
Amine and Amino Acid Transmitters
1. Precursor uptake
2. Transmitter synthesis
3. Transmitter storage
4. Degradation of surplus transmitter
5. Depolarization
6. Ca++ influx
7. Release of transmitter
8. Diffusion of transmitter
9. Binding of transmitter with receptor
10. Inactivation of transmitter
11. Reuptake – 1
12. Reuptake – 2
13. Interaction with presynaptic receptors
