Pharmacology

Question 1

What is the general function of muscarinic receptors? What type of stimulation do they receive?

Answer 1

cholinergic -> stimulate contraction of smooth muscle and increases gland secretion

Question 2

Where are M2 and M3 receptors located? How does each of the work?

Answer 2

M2 - heart, nerves, smooth muscle -> inhibit adenylyl cyclase
M3 - glands, smooth muscle, endothelium -> activate phospholipase C, IP3, and DAG

Question 3

What is the general function of alpha 1 adrenergic receptors? How does it work and what is the primary agonist?

Answer 3

• vasoconstriction and glandular secretion -> stimulates PLC, IP3, DAG, and intracellular Ca
• Epi main agonist

Question 4

What is the general function of beta 2 adrenergic receptors? How does it work and what is the primary agonist?

Answer 4

• relaxes smooth muscle, vasodilation, bronchodilation -> stimulates adenylyl cyclase
• Ep main agonist

Question 5

What catalyzes the synthesis of ACh? What 2 things combine to make ACh?

Answer 5

choline and Acetyl CoA make ACh using choline acetyltransferase (ChAT)

Question 6

What stimulates the fusion of ACh vesicles w/ the synaptic cleft?

Answer 6

Ca entering the neuron

Question 7

What influx occurs on the postsynaptic side of ACh binding to cholinergic receptors?

Answer 7

Na influx -> depolarization

Question 8

What terminates ACh signaling and what is ACh cleaved into?

Answer 8

Acetylcholinesterase cleaves ACh into acetate and choline (choline recycled)

Question 9

What is used to synthesize catecholamines?

Answer 9

tyrosine -> Dopa -> dopamine

Question 10

What signals the release of catecholamines in the adrenal medulla?

Answer 10

presynaptic fiber releasing ACh to bind to nicotinic receptors on chromaffin cells

Question 11

How do parasympathetics have a way to control smooth muscle of blood vessels? What triggers its release?

Answer 11

indirectly through NO released by endothelial cells after ACh binds to M3 receptors on endothelial cells

Question 12

Which type of receptor is most dominantly located on vascular smooth muscle?

Answer 12

alpha 1

Question 13

Name 5 reactions to the parasympathetic nervous system

Answer 13

• salivation, lacrimation
• pupil constriction
• decrease HR
• urination, dedication
• increased secretion and motility of GI tract

Question 14

Name 5 reactions to the sympathetic nervous system

Answer 14

• cutaneous vasodilation
• pupil dilation
• increase HR
• reduced desire to urinate
• decreased secretion and motility of GI tract

Question 15

Where do you generally find nicotinic receptors?

Answer 15

skeletal muscle and where presynapatic and postsynaptic fibers meet

Question 16

What affect does activation of mAChRs have on the detrusor M. of the bladder?

Answer 16

contraction of detrusor -> urination

Question 17

How does activation of the mAChRs cause trigone and sphincter relaxation if it is contracting the detrusor M.?

Answer 17

NO -> ACh binds to M3 receptors on endothelial cells which releases NO to relax the sphincters and allow urination

Question 18

What type of effect is a muscarinic antagonist going to have on the GI system?

Answer 18

decrease parasympathetic activity -> constipation and dry mouth

Question 19

What is a pheochromocytoma and where is it usually found?

Answer 19

adrenaline secreting tumor usually sitting in the adrenal medulla

Question 20

What is tested in the urine to dx a pheochromocytoma and where does this come from?

Answer 20

metanephrine is tested in the urine -> byproduct of catecholamine metabolism

Question 21

What receptors increase and decrease HR?

Answer 21

M2 - decrease HR

Beta 1 - increase HR

Question 22

What would happen if you gave a beta-blocker to someone w/ a pheochromocytoma?

Answer 22

unopposed alpha stimulation -> catecholamines still being produced and can only bind to alpha receptors -> increased vasoconstriction and possible death

Question 23

What is the location and function of alpha 2 receptors?

Answer 23

found presynaptically in the CNS; suppress further sympathetic activation when activated

Question 24

Which group of receptors are most connected to the parasympathetic nervous system?

Answer 24

muscarinic receptors

Question 25

Under what type of control are sweat glands? What type of receptor is responsible for sweat glands?

Answer 25

sympathetic -> muscarinic (not what you would normally think)

Question 26

What would occur first if you ingested an AChE inhibitor in each of the following methods: ingestion, percutaneous absorption, lipid-soluble AChE inhibitors?

Answer 26

• ingestion: GI sx -> salivation, defecation, emesis
• percutaneous: localized sweating and muscle fasciculations
• lipid-soluble: CNS involvement very rapid (crosses blood brain barrier)

Question 27

In what substances would you find AChE inhibitors?

Answer 27

organophosphates (insecticides)

Question 28

Name 3 antidotes for organophosphate exposure

Answer 28

atropine (inhibit mAChRs), oxime (uncouple interaction between AChE and AChE inhibitor, benzodiazepine (alleviate convulsions)

Question 29

What is myasthenia graves?

Answer 29

autoimmune disorder that decreases expression of nAChRs on skeletal muscle (causes muscle weakness)

Question 30

What class of drug is used to treat myasthenia graves? What will this do to muscarinic receptors?

Answer 30

AChE inhibitor; will increase ACh at nicotinic and muscarinic receptors (cause adverse effects)

Question 31

What can be given along with a AChE inhibitor to prevent adverse effects at muscarinic receptors?

Answer 31

muscarinic antagonist