Neuromuscular Blockers

Question 1

Describe the nicotinic acetylcholine receptor.

Answer 1

It is sodium ligand gated ion channel that is involved in the depolarisation of neurons. It is a pentamer composed of the subunits a (for which there are 9 subtypes) b (for which tere are 4 subtypes and d e and y. There are 3 types of nicotinic receptors in the body - the muscle type (a1)2b1dy, the brain type (a3)2(b4)3 and the CNS type (a7)5 (a4)2(b2)3. The 5 subunits form a pore which is blocked by two leuicines with strong negative charges these attract the positive ions so when aceyylvholine binds and pulls the two leucines apart the sodium then flows into the cell against its concentration gradient.

Question 2

Tubocurarine

Answer 2

Tubcurarine is a potent nicotinc receptor antagonist that is used a muscle relaxant in surgery to stop muscle spasms (has a specific order that it relaxes the muscles eyes >face>limbs>respiratory muscles).

Question 3

Pancuronium and Atricurium

Answer 3

Non-depolarising neuromuscular blockers used in trachel intubation

Question 4

Decamethonium

Answer 4

Partial agonist at acetylcholine nictonic receptor. Is a depolarising neuromuscular blocker whereby it stimulates the receptors so much they are desensitised so involves a period of muscle spasm followed by flaccid paralysis