Pharmacology - Problem Drill 11: Vasoactive Agents Question No. 1 of 10 1. Vascular smooth muscle contraction is triggered by a rise in. Question #01 (A) Luminal calcium (B) Extracellular calcium (C) Intracellular calcium (D) Extracellular sodium (E) Intracellular sodium Think of calcium in a different location. Think of calcium in a different location. C. Correct! Smooth muscle cell contraction is initiated by a rise in intracellular calcium, which activates myosin light chain kinase causing phosphorylation of myosin. Think of a different ion. Think of a different ion. Smooth muscle cell contraction is initiated by a rise in intracellular calcium, which activates myosin light chain kinase causing phosphorylation of myosin. The correct answer is (C).
Question No. 2 of 10 Instructions: (1) Read the problem and answer choices carefully (2) Work the problems on paper as needed (3) Pick the answer (4) Go back to review the core concept tutorial as needed. 2. causes release catecholamines. Question #02 (A) Enalapril (B) Amphetamine (C) Endothelins (D) Kinins (E) Nitric oxide Enalapril is a prodrug that is taken orally and converted in the body to the ACE Inhibitor enalaprilat. B. Correct! Amphetamine causes release catecholamines. Feedback on Each Answer Endothelin is a long-acting vasoconstrictor peptide. Kinins are formed by the catalytic activity of kallikreins on kininogens. Nitric oxide causes smooth muscle relaxation by increasing cgmp formation. Amphetamine causes release catecholamines. Its effects are similar to ephedrine, but it enters the central nervous system more readily where it produces significant alertness and appetite suppressant effects. The correct answer is (B).
Question No. 3 of 10 3. The combination of the epithelium with its basement membrane is called the. Question #03 (A) Tunica intermedia (B) Tunica interna (C) Tunica externa (D) Lumen (E) None of the above Surrounding the basement membrane is a layer of smooth muscle which also has an underlying layer of connective tissue, the combination of which is called the tunica intermedia. B. Correct! The combination of the epithelium with its basement membrane is called the tunica interna. The tunica externa helps in keeping the shape of the blood vessels intact through cycles of constriction and relaxation. The lumen is the interior of the blood vessel. One of the answers is correct. The combination of the epithelium with its basement membrane is called the tunica interna. Surrounding the basement membrane is a layer of smooth muscle which also has an underlying layer of connective tissue, he combination of which is called the tunica intermedia. Surrounding this layer is a tough layer of connective tissue called the tunica externa that helps keep the shape of blood vessels intact through cycles of constriction and relaxation. The correct answer is (B).
Question No. 4 of 10 4. determine(s) systolic wall stress. Question #04 (A) Endothelial cells (B) Arteriolar tone (C) Venous tone (D) Intracellular calcium (E) Endothelin Endothelial cells release various vasoactive substances, including the vasodilators prostacyclin and nitric oxide. B. Correct! Arteriolar tone determines systolic wall stress and venous tone the diastolic wall stress. Think of the other type of vascular tone. Intracellular calcium regulates smooth muscle contractions. Endothelin is a vasoactive peptide. Arteriolar tone determines systolic wall stress and venous tone the diastolic wall stress. Since the contraction and relaxation of the smooth muscle that comprises the arteries and veins occurs in several steps, different drugs can affect vascular tone by acting upon various stages of this cycle. The correct answer is (B).
Question No. 5 of 10 5. are also known as sympathomimetics, since the adrenoceptors are found primarily in the sympathetic system. Question #05 (A) Peptides (B) Adrenoceptors agonists (C) Nitric oxides (D) Vasodilators (E) Vasoconstrictors Most sympathomimetics are not peptides. B. Correct! Adrenoceptors agonists are also known as sympathomimetics, since the adrenoceptors are found primarily in the sympathetic system. Nitric oxide acts via cgmp to cause smooth muscle relaxation. Nitric oxide acts via cgmp to cause smooth muscle relaxation. Vasoconstrictors cause narrowing of blood vessel due to contraction of vascular smooth muscle. Adrenoceptors agonists are also known as sympathomimetics, since the adrenoceptors are found primarily in the sympathetic system. The correct answer is (B).
Question No. 6 of 10 6. is a mixed action sympathomimetic that is found naturally in Ma-Huang and has been used in Chinese medicine for centuries. Question #06 (A) Pseudoephedrine (B) Thromboxane (C) Ephedrine (D) Aspirin (E) Bradykinin Pseudoephedrine, an ephedrine enantiomer, is a derivative of ephedrine that is widely used as a decongestant. Thromboxane is a type of eicosanoid that is a potent vasoconstrictor. Thromboxane is produced by platelets, and plays a role in increasing platelet aggregation. C. Correct! Ephedrine is a mixed action sympathomimetic that is found naturally in Ma-Huang and has been used in Chinese medicine for centuries. Aspirin functions to inhibit the production of thromboxane by inhibiting cycloxygenase (COX) enzymatic activity within platelets, thereby inhibiting thromboxane production and inhibiting platelet aggregation. Bradykinin is a kinin, not a sympathomimetic. Ephedrine is a mixed action sympathomimetic that is found naturally in Ma-Huang and has been used in Chinese medicine for centuries. It is absorbed into the central nervous system where it acts as a mild Stimulant. It is a noncatechol phenylisopropylamine and therefore has a long duration of action and a High bioavailability. The correct answer is (C).
Question No. 7 of 10 7. causes an increase in blood pressure. Question #07 (A) Angiotensin II (B) Aldosterone (C) Renin (D) ACE Inhibitors (E) None of the above A. Correct! Angiotensin II causes an increase in blood pressure. Aldosterone causes the kidneys to increase their reabsorption of water and sodium, which increases body fluid volume and, in turn, increases blood pressure. Decreased pressure stimulates the production of renin which increases the production of angiotensin II. ACE Inibitors and Angiotensin Receptor Blockers work to block the effects of angiotensin II. There is one correct answer above. One type of vasoconstrictor is angiotensin II. Decreased pressure stimulates the production of renin which increases the production of angiotensin II. Angiotensin II causes an increase in blood pressure by direct constriction of resistance vessels and stimulation of aldosterone synthesis. Aldosterone in turn causes the kidneys to increase their reabsorption of water and sodium, which increases body fluid volume and, in turn, increases blood pressure. Too much activity of the renin-angiotensin system can lead to high blood pressure. The correct answer is (A).
Question No. 8 of 10 8. causes pallor, abdominal cramps and may precipitate cardiac ischemia. Question #08 (A) Vasopressin (B) Desmopressin (C) Endothelin (D) Neuropeptide Y (E) Urotensin A. Correct! Vasopressin causes pallor, abdominal cramps and may precipitate cardiac ischemia. Desmopressin is selective for V2 vasopressin receptors and therefore has fewer side effects than vasopressin. Endothelin produces vasoconstriction, bronchoconstriction and stimulation of aldosterone secretion. Neuropeptide Y produces increased feeding, hypothermia, respiratory depression, and vasoconstriction of cerebral blood vessels, positive chrontropic and inotropic actions on the heart as well as hypertension. Urotensin s vasoconstrictor effect depends upon the type of blood vessel and the species from which it was obtained and under some circumstances it may even cause vasodilatation. Vasopressin is a peptide hormone, which causes generalized vasoconstriction and is sometimes used to treat patients with bleeding esophageal varices and portal hypertension before more definitive treatment. It causes pallor, abdominal cramps and may precipitate cardiac ischemia. The correct answer is (A).
Question No. 9 of 10 9. are produced by the fungus Claviceps purpurea, which grows on grains, especially rye. Question #09 (A) Catecholamines (B) Atrial natriuretic peptide (C) The ergot alkaloids (D) Vasopressin (E) Dopamine Think of an alkaloid, not a catecholamine. Atrial natriuretic peptide is a type of natriuretic peptides found in the atria and other tissues of mammals. C. Correct! The ergot alkaloids are produced by the fungus Claviceps purpurea, which grows on grains, especially rye. Vasopressin is not produced by fungus. Dopamine is not produced by fungus. Ergot alkaloids are produced by the fungus Claviceps purpurea, which grows on grains, especially rye. Ergotamine and related compounds are typically vascoconstrictive, with some action at vascular alpha adrenergic receptors and serotonin receptors. Vascular tissue has differential sensitivity to ergot alkaloids, with cerebral arteriovenous vessels exhibiting heightened sensitivity to ergotamine and the related drug sumatriptan (Imitrex). This is the basis of using ergot alkaloids to treat vascular migraines. The correct answer is (C).
Question No. 10 of 10 10. is a tachykinin found in the central nervous system and gastrointestinal tract. Question #10 (A) Neurotensin (B) CGRP (C) Propranolol (D) Atenolol (E) Substance P Neurotensin is a tridecapeptide that is synthezised as part of a larger molecule present in the central nervous system, gastrointestinal tract and the circulation. CGRP is found in the thyroid gland as well as the central and peripheral nervous systems. In the systemic circulation it causes hypotension and tachycardia, while in the central nervous system it produces hypertension and suppression of feeding. Propranolol was the first beta-blocker shown to be effective in hypertension by decreasing cardiac output. Atenolol is a sympathomimeitc, not a peptide. E. Correct! Substance P is a tachykinin found in the central nervous system and gastrointestinal tract. It is a potent vasodilator that produces marked hypotension and also causes behavioral changes, anxiety, depression, nausea and vomiting. Substance P is a tachykinin found in the central nervous system and gastrointestinal tract. It is a potent vasodilator that produces marked hypotension and also causes behavioral changes, anxiety, depression, nausea and vomiting. Its vasodilator effect is exerted through the release of nitric oxide from the endothelium. In the venous, intestinal and bronchial smooth muscle it causes muscle contraction. The correct answer is (E).