Medical Pharmacology Practice Questions: Cholinergic Pharmacology

Cholinergic-receptor-mediated vasodilation -- changes in intracellular concentration of this ion is principally responsible:
1. sodium
2. potassium
3. chloride
4. calcium
5. magnesium
Cholinergic-mediated vasodilation involves liberation of this substance, a gas, from endothelial cells:
1. prostaglandins
2. leukotrienes
3. nitric oxide
4. calcium
Mechanism(s) of vasodilation mediated by the cholinergic system:
1. cholinergic activation promotes nitric oxide release from endothelial cells
2. acetylcholine inhibits norepinephrine release from postganglionic sympathetic fibers
3. both
4. neither
Parasympathetic system: negative chronotropic effect --
1. mediated by M2 muscarinic receptors
2. associated with increased diastolic depolarization (increased phase 4 depolarization)
3. both
4. neither
Major mechanism responsible for decreased AV nodal conduction following increased vagal tone:
1. decreased calcium currents in the AV node
2. secondary affected to reduced norepinephrine release
3. decreased sodium currents in the AV node
4. increased potassium conductance in the AV nodal fibers
5. all of the above
Associated with excessive vagal tone:
1. partial heart block
2. total heart block
3. other bradyarrhythmias
4. all the above
Concerning negative inotropism associated with increased vagal tone:
1. more prominent in atrial compared to ventricular muscle
2. due to a decrease in inward calcium currents
3. both
4. neither
Dominating autonomic tone in the ventricle:
1. sympathetic
2. parasympathetic
Mechanisms by which muscarinic stimulation reduces ventricular contractility:
1. reduces ventricular responds to norepinephrine
2. reduces norepinephrine release from adrenergic terminals
3. both
4. neither
Effects of muscarinic receptor activation and cardiac ionic currents:
1. decreases potassium currents in atrial muscle and in SA nodal MAb nodal tissue
2. increases in slow, inward calcium currents
3. decreased in diastolic depolarization (decrease in phase 4 depolarization)
4. A & C
5. B & C
Effect(s) of muscarinic agonists on the gastrointestinal and urinary tracts:
1. increased intestinal peristalsis
2. increased tone
3. increased contraction amplitude
4. increase ureteral peristalsis
5. all the above
Substances that increase nitric oxide production:
1. substance P
2. bradykinin
3. acetylcholine
4. A & B
5. A, B & C
Clinical uses of bethanecol:
1. management of postoperative abdominal distention
2. management of esophageal reflux
3. postoperative urinary bladder stimulant
4. treatment of reduced salivation secondary to radiation therapy
5. all the above
Opthalmological uses of cholinomimetics:
1. acetylcholine may be used as a miotic
2. treatment of glaucoma
3. used along with mydriatic agent in breaking iris-lens adhesions
4. A & B
5. A, B &C
Major contraindications -- muscarinic agonists
1. asthma
2. hyperthyroidism
3. peptic ulcer
4. coronary vascular disease
5. all the above