WK7-nicotinic receptors

What are the three main sub-types of nicotinic receptors

Muscle, ganglionic, and CNS types.

What type of channel are nicotinic receptors?

Ligand-gated ion channels.

What does nicotine mimic at nicotinic receptors?

The action of acetylcholine (ACh).

Are most nicotinic agonists selective or non-selective?

Non-selective (e.g., ACh, nicotine)

Which nicotinic agonist is selective for muscle nAChRs?

Suxamethonium (succinylcholine) (selective)

What are the two mechanisms for neuromuscular block?

Competitive inhibition (tubocurarine) (non-depolarising) and depolarising block (nicotine).

What type of block does tubocurarine produce?

non-depolarising (competitive inhibition) which overcome by increased ach

What is a key characteristic of a depolarising block?

Persistent stimulation leads to desensitization and Phase II block

Which depolarising agents act at the NMJ?

Nicotine, ACh (with cholinesterase inhibitors), suxamethonium.

Why is tubocurarine no longer used clinically?

Due to side effects like hypotension and histamine release.

Name foursynthetic non-depolarising agents used clinically

Pancuronium (LDOA), vecuronium(Intermmedite DOA), atracurium (intermmediate DOA) , mivacurium(SDOA)

What is the clinical use of suxamethonium?

used for brief neuromuscular block like Short-term paralysis for tracheal intubation.

What are the side effects of suxamethonium?

Prolonged paralysis in neonates, liver disease, or genetic variants lacking cholinesterase.