79 Questions
Which enzyme is responsible for the formation of histamine?
Histidine decarboxylase
What inhibits the release of histamine?
Epinephrine
What is the mechanism of action of H2 receptor antagonists?
Stimulation of H+/K+ ATPase activity
Which drug is known for reducing acid secretion by approximately 70%?
Ranitidine
What is essential for vesicle exocytosis and gastric acid secretion?
TRPML1
Which of the following is NOT a use for drugs affecting the gastrointestinal system?
Control of blood pressure
Which part of the gastrointestinal tract is responsible for increasing secretions and gut motility, and relaxation of sphincters?
Small intestine
Which of the following exocrine glands is NOT part of the gastrointestinal tract?
Liver
Which type of neurons project to the gut to decrease gut motility and contract sphincters?
Sympathetic neurons
Where do the vagal afferent neurons receive sensory information from the gut?
In the nodose and inferior jugular ganglia
Which class of drugs has a marked effect on nocturnal acid secretion but only a modest effect on meal-stimulated secretion?
H2-receptor antagonists
Which drug is more potent than Cimetidine, leading to less frequent dosing?
Ranitidine
Which type of antacids may cause rebound acid secretion if used chronically and may lead to hypercalcemia?
Calcium carbonate
Which class of drugs suppresses both meal-stimulated and nocturnal acid secretion?
Proton Pump Inhibitors (PPIs)
Which drug is used to prevent NSAID-induced ulcers but has side effects such as diarrhea and abdominal cramping?
Misoprostol
Which side effect is specifically associated with aluminum hydroxide in antacids?
Constipation
What is the specific effect of bismuth subsalicylate when exposed to gastric acid?
Forms a paste coating the ulcer
How does sucralfate function in the treatment of ulcers?
Requires low pH for activation
What is the optimum treatment for patients with peptic ulcer disease infected with H. pylori?
Quadruple therapy including metronidazole and tetracycline
What is the main concern for renal failure patients using antacids?
Systemic alkalosis from absorption of cations in antacids
What is the main clinical advantage of stimulating postpartum lactation?
Promotion of colonic evacuation
What is the main reason for the decreased use of Bathanechol in the treatment of GERD and gastroparesis?
Side effects
What is the main use of neostigmine in hospitalized patients?
Colonic evacuation
What is the primary effect of erythromycin on the gastrointestinal system?
Increase in GI motility
In which scenario should antibacterial drugs NOT be used in the treatment of diarrhea?
Bloody diarrhea
Which condition is a possible cause of chronic diarrhea?
Lactose intolerance
What is the primary effect of antimotility agents on the gastrointestinal system?
Increased peristalsis
What is the main mechanism of action of adsorbents in the treatment of severe diarrhea or dysentery?
Absorption of intestinal toxins
What is the primary clinical use of Bismuth subsalicylate in managing diarrhea?
Decrease in fluid secretion
What is the primary action of opioid agonists on the gastrointestinal system?
Increased propulsion and peristalsis
What is the primary stimulus for the production of hydrochloric acid (HCl) by parietal cells in the stomach?
Acetylcholine
Which of the following is NOT a mechanism to protect the gastric mucosa from damage by gastric acid?
Pepsin secretion
Which condition is characterized by gastrin-secreting pancreatic adenomas and leads to multiple ulcers and increased gastric acid and pepsin secretion?
Zollinger-Ellison syndrome
What is the first choice for acid suppression and is used for the prevention and treatment of gastroesophageal reflux disease, erosive esophagitis, active duodenal ulcer, and pathologic hypersecretory conditions?
Proton pump inhibitors (PPIs)
Which class of acid-suppressing drugs competes with K+ to inhibit the H+/K+–ATPase and inhibit gastric acid secretion into the stomach lumen?
K+-competitive acid blockers (P-CABs)
Which of the following laxatives works through an osmotic effect, increasing water and stretching the bowel?
Sodium phosphate
What is the mechanism of action of stool softeners like docusate sodium and docusate calcium?
Lowering surface tension of stool
Which condition is characterized by delayed gastric emptying and can be caused by diabetes mellitus?
Gastroparesis
What is the clinical use of prokinetic drugs like metoclopramide and domperidone?
Management of gastroesophageal reflux disease
What are the side effects of prokinetic drugs like metoclopramide and domperidone?
Extrapyramidal symptoms
Which H2 receptor antagonist is known for reducing acid secretion by approximately 70%?
Famotidine
What is the primary clinical advantage of stimulating postpartum lactation?
Inhibiting gastric acid secretion
What is the main concern for renal failure patients using antacids?
Hypercalcemia
Which type of neurons project to the gut to decrease gut motility and contract sphincters?
Sympathetic postganglionic neurons
What is the mechanism of action of stool softeners like docusate sodium and docusate calcium?
Increase water and stretching of the bowel through an osmotic effect
Which drug class is primarily used for the treatment of peptic ulcers and gastritis?
Proton pump inhibitors
What is the primary mechanism of action of drugs used for the treatment of GERD?
Inhibiting gastric acid secretion
Which drug is commonly used to reduce gastric acid secretion by inhibiting H+/K+–ATPase?
Cimetidine
What is the primary clinical use of Bismuth subsalicylate in managing gastrointestinal disorders?
Managing diarrhea
Which condition is characterized by delayed gastric emptying and can be caused by diabetes mellitus?
Gastroparesis
Which enzyme is responsible for the formation of histamine?
Histidine decarboxylase
What inhibits the release of histamine?
Epinephrine
What is essential for vesicle exocytosis and gastric acid secretion?
TRPML1
Which drug is more potent than Cimetidine, leading to less frequent dosing?
Famotidine
What is the mechanism of action of H2 receptor antagonists?
Inhibition of the H+/K+–ATPase proton pump
Which of the following is NOT a cause of peptic ulcers?
Inadequate mucus secretion
What is the specific effect of sodium bicarbonate in antacids?
It neutralizes gastric acid, producing CO2
Which of the following is an adverse effect of proton pump inhibitors (PPIs)?
Hypokalemia
What is the primary concern for renal failure patients using antacids?
Systemic alkalosis
What is the primary mechanism of action of K+-competitive acid blockers (P-CABs)?
Forming a covalent bond with H+/K+-ATPase
What is the optimum treatment for patients with peptic ulcer disease infected with H. pylori?
Quadruple therapy including sucralfate, metronidazole, tetracycline, and a PPI
Which condition is characterized by gastrin-secreting pancreatic adenomas?
Zollinger-Ellison syndrome
What is the specific function of bismuth subsalicylate in the treatment of peptic ulcers?
Forms a paste when exposed to gastric acid, coating the ulcer and protecting it from acids and pepsin
How do proton pump inhibitors (PPIs) suppress hydrogen ion secretion into the gastric lumen?
By forming a covalent bond with H+/K+-ATPase
What is the main effect of mucosal protective agents like sucralfate in the treatment of ulcers?
Promotes healing of duodenal ulcers
What is the primary effect of prokinetic drugs like metoclopramide and domperidone on the gastrointestinal system?
Stimulating GI motility and lower esophageal sphincter tone
What is the main cause of gastroparesis?
Nervous system disorders
How do bulk-forming laxatives work to soften feces?
By absorbing and retaining water
What is the mechanism of action of stool softeners like docusate sodium and docusate calcium?
Lowering surface tension of feces
What is the primary adverse effect associated with sodium saline cathartics?
Electrolyte imbalance
What is the primary mechanism of action of neostigmine in hospitalized patients?
Competitive acetylcholinesterase inhibition
What is the primary clinical use of Bismuth subsalicylate in managing diarrhea?
Adsorbing intestinal toxins or microorganisms
What is the primary stimulus for the production of hydrochloric acid (HCl) by parietal cells in the stomach?
Gastrin
Which drug class competes with K+ to inhibit the H+/K+–ATPase and inhibit gastric acid secretion into the stomach lumen?
H2 receptor antagonists
What is essential for vesicle exocytosis and gastric acid secretion?
Acetylcholine
Which type of neurons project to the gut to decrease gut motility and contract sphincters?
Parasympathetic neurons
What is the mechanism of action of stool softeners like docusate sodium and docusate calcium?
Increasing water and stretching the bowel
Which class of drugs suppresses both meal-stimulated and nocturnal acid secretion?
H2 receptor antagonists
What is the primary effect of erythromycin on the gastrointestinal system?
Increase GI motility
Study Notes
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Circular muscles behind bolus contract, muscles in front relax, propelling the bolus forward
-
Peristalsis is stimulated by an intraluminal bolus distention of the intestinal wall
-
Contact cathartics such as castor oil and bisacodyl increase intestinal motor activity and act on the small intestine
-
Bulk-forming laxatives absorb and retain water, softening feces and may reflexively stimulate peristalsis
-
Sodium saline cathartics work through an osmotic effect, increasing water and stretching the bowel, but can cause electrolyte imbalance and other side effects
-
Stool softeners keep feces soft to prevent discomfort and don't directly stimulate peristalsis
-
Prokinetic drugs increase gastric motility and can be beneficial for gastroesophageal reflux disease, gastric emptying, and constipation
-
Gastroparesis is a condition characterized by delayed gastric emptying, caused by various factors including diabetes and smooth muscle disorders
-
Prokinetic drugs like metoclopramide and domperidone act as D2 receptor antagonists, indirectly stimulating acetylcholine release and increasing GI motility and lower esophageal sphincter tone.
-
Cathartics can be contact (stimulant-irritant) like castor oil or bisacodyl or bulk-forming like psyllium, bran, or methylcellulose, or saline (osmotic) like magnesium hydroxide, sodium phosphate, or polyethylene glycol.
-
Stool softeners include docusate sodium or docusate calcium and mineral oil, and work by lowering surface tension or slowing down water reabsorption, respectively.
-
Side effects of laxatives include electrolyte imbalance, intestinal obstruction, lipid pneumonia, and potential foreign-body reactions.
-
Gastroparesis causes can include diabetes mellitus, smooth muscle disorders, nervous system disorders, and idiopathic causes.
-
Prokinetic drugs stimulate gastric motility and can be beneficial for gastroesophageal reflux disease, gastric emptying, and postoperative ileus or constipation.
-
Metoclopramide and domperidone are prokinetic drugs that act as D2 receptor antagonists, indirectly stimulating acetylcholine release and increasing GI motility and lower esophageal sphincter tone.
-
Prokinetic drugs have clinical uses in gastroparesis, gastroesophageal reflux disease, chronic dyspepsia, and as antiemetics.
-
Side effects of prokinetic drugs include extrapyramidal symptoms similar to those seen with typical antipsychotics.
-
Circular muscles behind bolus contract, muscles in front relax, propelling the bolus forward
-
Peristalsis is stimulated by an intraluminal bolus distention of the intestinal wall
-
Contact cathartics such as castor oil and bisacodyl increase intestinal motor activity and act on the small intestine
-
Bulk-forming laxatives absorb and retain water, softening feces and may reflexively stimulate peristalsis
-
Sodium saline cathartics work through an osmotic effect, increasing water and stretching the bowel, but can cause electrolyte imbalance and other side effects
-
Stool softeners keep feces soft to prevent discomfort and don't directly stimulate peristalsis
-
Prokinetic drugs increase gastric motility and can be beneficial for gastroesophageal reflux disease, gastric emptying, and constipation
-
Gastroparesis is a condition characterized by delayed gastric emptying, caused by various factors including diabetes and smooth muscle disorders
-
Prokinetic drugs like metoclopramide and domperidone act as D2 receptor antagonists, indirectly stimulating acetylcholine release and increasing GI motility and lower esophageal sphincter tone.
-
Cathartics can be contact (stimulant-irritant) like castor oil or bisacodyl or bulk-forming like psyllium, bran, or methylcellulose, or saline (osmotic) like magnesium hydroxide, sodium phosphate, or polyethylene glycol.
-
Stool softeners include docusate sodium or docusate calcium and mineral oil, and work by lowering surface tension or slowing down water reabsorption, respectively.
-
Side effects of laxatives include electrolyte imbalance, intestinal obstruction, lipid pneumonia, and potential foreign-body reactions.
-
Gastroparesis causes can include diabetes mellitus, smooth muscle disorders, nervous system disorders, and idiopathic causes.
-
Prokinetic drugs stimulate gastric motility and can be beneficial for gastroesophageal reflux disease, gastric emptying, and postoperative ileus or constipation.
-
Metoclopramide and domperidone are prokinetic drugs that act as D2 receptor antagonists, indirectly stimulating acetylcholine release and increasing GI motility and lower esophageal sphincter tone.
-
Prokinetic drugs have clinical uses in gastroparesis, gastroesophageal reflux disease, chronic dyspepsia, and as antiemetics.
-
Side effects of prokinetic drugs include extrapyramidal symptoms similar to those seen with typical antipsychotics.
Test your knowledge of intestinal peristalsis and bolus movement with this quiz. Explore the mechanisms involved in the propulsion of the bolus through the digestive system and the role of circular and longitudinal muscles.
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