Where are large amts. of Ach released at
Presynaptic vesicles when voltage gated calcium channels open in response to membrane depolarization
what receptors do AcH act on ?
nictonic( neuromuscular junction of skeletal muscle, within ganglion and CNS) and muscarinic( widely distributed within both peripheral and central nervous system)
How does Choline Inhbitors work?
Prevents enzyme from hydrolyzing acethlcholine( inactivating) AcH. This inhibition permits the buildup of acetylcholine and results in more intensive and prolonged activation of the receptor site
How does Pilocarpine work?
PIlocarpine constrics the ciliary muscle which permits drainage of the aqueous humor and thus relieves pressure due to a glaucoma condition
Cholinergic Blocking Agents
Cholinergic blocking agents prevents acetylcholine from stimulating the receptor site and thus act as antagonists. These compounds compete with acetylcholine for receptor sites. They do not themselves produce an excitant effect but rather limit the excitant effects of acetylcholine.
Effects of Cholinergic Blocking Agents
saliva, sweat, and gastric acid in the stomach are decreased; tone and movements of smooth muscles in the gastrointestinal tract and respiratory bronchioles are reduced at high doses- pupils are dilated; and paralysis of eye muscles changes the shape of the lens.