Receptors

Question 1

Nicotinic receptors are located on cell bodies in ganglia of both PANS and SANS and in the adrenal medulla

Answer 1

Nn

Question 2

Nicotinic receptors are located on the skeletal muscle motor end plate innervated by somatic motor nerves

Answer 2

Nm

Question 3

Muscarinic receptors are located on all organs and tissues innervated by postganglionic nerves of the PNS and on thermoregulatory sweat glands innervated by the SNS.

Answer 3

M1-M3

Question 4

Systemically, alpha-1 agonist increase mean BP via vasoconstriction
• Increased BP may elicit a reflex bradycardia
• Cardiac output may be ↓ but also offset by ↑ venous return
• Drugs and uses: nasal decongestant and ophthalmologic uses(Mydriasis without cycloplegia), hypotensive states

Answer 4

Phenylephrine

Alpha 1 agonist

Question 5

α1:↑TPR,↑BP
• Potential reflex bradycardia
• No change in pulse pressure

Answer 5

A1 Agonist Phenylephrine

Question 6

Alpha-2 agonists stimulate prejunctional receptors in the CNS to decrease
sympathetic outflow. Their primary use is for mild to moderate HTN.
• Drugs and uses: (mild to moderate hyper- tension)

Answer 6

clonidine and methyldopa

Question 7

Systemically decrease mean BP via vasodilation (β2) and 
increase HR (β1)

• β1: ↑HR,↑SV,↑CO, and ↑ pulse pressure
• β2:↓TPR,↓BP

Answer 7

beta-agonists

– Isoproterenol (β1 = β2)
– Dobutamine (β1 > β2): congestive heart failure

Selective β2 agonists: salmeterol, albuterol, terbutaline (asthma); terbutaline(premature labor)

Question 8

Mixed acting Agonists

(α1, α2, β1)

α1:↑TPR,↑BP
• β1: ↑ HR↑SV↑CO↑ pulse pressure 
• Potential reflex
bradycardia
• No effect on β2

Answer 8

Norepinephrine

Question 9

(α1, α2, β1, β2)

β1:↑HR,↑SV,↑CO,
↑ pulse pressure

β2:↓TPR,↓BP

Answer 9

Epinephrine

Low-dose Epinephrine on HR and BP

Question 10

β1:↑HR,↑SV,↑CO
↑pulse pressure

β2:↓TPR,↓BP
α1:↑TPR,↑BP

Answer 10

Epinephrine

Medium Dose on Heart Rate and Blood Pressure

Question 11

α1:↑TPR,↑BP
Potential reflex
bradycardia

• β1:↑HR,↑SV,↑CO,
↑ pulse pressure
• β2:↓TPR,↓BP

Answer 11

Epinephrine

High Dose Epi/ Similar to NE

Question 12

↓ HR, ↓ SV, ↓ CO

↓ renin release

Answer 12

β1 Blockade

Question 13

May precipitate bronchospasm (in asthmatics) and vasospasm (in
patients with vasospastic disorders)
– ↓aqueous humor production
– Metabolic effects
o Blocks glycogenolysis, gluconeogenesis
o ↑ LDLs, TGs

Answer 13

β2 blockade

Question 14

Activation of M receptors causes contraction of ciliary muscle, which increases flow through the canal of Schlemm

Answer 14

Cholinomimetic

ie Pilocarpine

Question 15

Block actions of NE at ciliary epithelium * aqueous humor formation

Answer 15

Beta blockers

ie Timolol

Question 16

α1-antagonists

Answer 16

doxazosin, prazosin, terazosin

Question 17

α2 antagonists

Answer 17

mirtazapine

Question 18

Mixed α antagonists:

Answer 18

phenoxybenzamine, phentolamine

Question 19

β1 (cardioselective) antagonists

Answer 19

acebutolol, atenolol, metoprolol

“A-M”

Question 20

β1, β2 (nonselective)

Answer 20

pindolol, propranolol, timolol

“N-Z”

Question 21

α1 and β antagonists

Answer 21

carvedilol, labetalol

Question 22

α1 agonists

Answer 22

phenylephrine

Question 23

α2 agonists

Answer 23

clonidine, methyldopa

Question 24

β agonists:

Answer 24

isoproterenol, (β1 = β2), dobutamine (β1 > β2)

Question 25

β2 agonists

Answer 25

albuterol, terbutaline, salmeterol

Question 26

Mixed Adrenergic Rc Activators

Answer 26

dopamine (D1, β1, α1),
epinephrine (α1, α2, β1, β2),
norepinephrine (α1, α2, β1)

Question 27

Indirect-acting adrenergics

Answer 27

amphetamine, cocaine, ephedrine, tyramine

Question 28

Muscarinic blockers

Answer 28

atropine, benztropine, ipratropium, scopolamine

Question 29

Ganglionic blockers:

Answer 29

hexamethonium, mecamylamine

Question 30

Direct Cholinergic activators

Answer 30

bethanechol (M), methacholine (M and N), nicotine (N), pilocarpine (M), cevimeline (M)

Question 31

Reversible AChE inhibitors:

Answer 31

reversible—edrophonium, physostigmine, neostigmine, pyridostigmine, donepezil, rivastigmine

Question 32

irreversible AChE inhibitors

Answer 32

irreversible—malathion, parathion