What I Don't Know

Question 1

Pee or no pee?

Answer 1

Increased pee:
Constrict detrusor smooth muscle, relax or stretch trigone muscle, relax bladder sphincter
M3 agonists, alpha-1 antagonists, beta-3 antagonists (don’t exist)

Decreased pee:
Relax detrusor smooth muscle, constrict trigone and bladder sphincter.
M3 antagonists (solifenacin, darifenacin), alpha-1 agonists (none used for decreased pee), beta-3 agonist (mirabegron).

Question 2

Paramomycin and streptomycin

Answer 2

Cooperative binding.

Question 3

Quinupristin and dalfopristin

Answer 3

Synergistic combination making synercid.

Question 4

Digoxin

Answer 4

Cause increase in inotropy, WITHOUT and increase in O2 consumption.

Question 5

M2 receptors

Answer 5

(1) Presynaptic ones inhibit Cav channels are pre-synaptic terminal.
(2) In SAN + AVN, they reduce heart rate via decreased Ca2+ channel phosphorylation and by triggering K(ACh).
(3) In atria, they reduce contractility via triggering K(ACh).

Question 6

Long acting anticholinesterases

Answer 6

Have very high lipid solubility and are rapidly absorbed through skin.

Question 7

nAChR structure

Answer 7

A functional nAChR is a pentamer consisting of a
combination of alpha, beta, gamma, delta, epsilon subunits with at least 2 alpha subunits present. Each subunit consists of four transmembrane (M1-M4) helices and the M2 helix from all five subunits form the pore. ACh binds to the interface between the alpha and neighbouring gamma delta subunits and minimally 2 molecules of ACh are required for
the activation of the channel leading to the opening its pore

Question 8

ANP

Answer 8

DIRECTLY-acting vasodilator.

AT2 receptor activation vasodilates INDIRECTLY via NO generation

Question 9

Bungarotoxin

Answer 9

BETA: Specific for cholinergic motor nerves and prevents ACh release.

ALPHA: Irreversibly binds and inhibits nAChRs at NMJ.

Question 10

Osmotic diuretics

Answer 10

Freely filtered at nephron and not reabsorbed at all.

Question 11

Loop vs Thiazide

Answer 11

Loop: VENOdilation to reduce preload. Venodilation happens BEFORE diuretic action. Blocks Na+-K+-2Cl- co-transport

Thiazide: VASOdilation which happens AFTER diuretic action. Blocking Na+-Cl- cotransport

Question 12

Amiodarone

Answer 12

USE-DEPENDENT inhibition of inward Na+ and Ca2+ currents.

Question 13

ACEI + diuretics

Answer 13

Diuretics lower ECV volume, causing more renin secretion, hence ACEI can act more.