Digestive Hormones Overview

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Questions and Answers

A researcher is investigating the impact of targeted vagal afferent stimulation on gastric motility in a murine model. Given the diverse sensory modalities transduced by vagal afferents, which specific stimulus is MOST likely to elicit a measurable change in gastric emptying rate?

High-frequency stimulation of vagal afferents sensitive to changes in serous mucous osmolarity within the duodenal bulb.

Selective activation of vagal afferents responsive to circulating VLDLs, inducing a satiety response.

Low-intensity mechanical stimulation designed to selectively activate stretch receptors within the gastric fundus. (correct)

Pharmacological blockade of all cholecystokinin receptors, thereby sensitizing the preparation to subtle chemical stimuli.

A patient presents with selective damage to the superior cervical ganglion following a surgical procedure. Which of the following gastrointestinal consequences is MOST likely to manifest?

Reduced production of gastrin causing achlorhydria.

Uncontrolled peristalsis in the colon due to loss of sacral nerve modulation.

Xerostomia due to impaired sympathetic innervation of the salivary glands. (correct)

Diminished bicarbonate secretion in the duodenum, leading to impaired neutralization of gastric chyme.

Following a cholecystectomy, a patient reports persistent postprandial bloating and indigestion, particularly after consuming high-fat meals. Which of the following compensatory mechanisms is LEAST likely to mitigate these symptoms?

Upregulation of pancreatic lipase secretion in response to elevated chyme lipid content.

Increased production of mucin-rich mucous in the colon to emulsify dietary fat. (correct)

Increased hepatic synthesis of plasma proteins to enhance lipid transport.

Adaptation of the small intestinal enterocytes to enhance absorption of non-emulsified lipids.

A researcher is investigating the effects of a novel neuropeptide on digestive function. They observe that administration of the neuropeptide leads to decreased gastric emptying, increased pancreatic enzyme secretion, and reduced colonic motility. Which combination of digestive reflexes is MOST likely potentiated by this neuropeptide?

Potentiation of the enterogastric reflex alongside inhibition of the gastrocolic reflex. (C) Signup and view all the answers

In a patient with chronic pancreatitis leading to exocrine insufficiency, which of the following therapeutic interventions would MOST directly address the impaired activation of pancreatic zymogens within the duodenal lumen?

Prescription of exogenous pancreatic enzyme supplements containing pre-activated forms of trypsin, chymotrypsin, and carboxypeptidase. (A) Signup and view all the answers

A researcher is studying the impact of selective vagotomy on the expression of antimicrobial peptides within the small intestinal lumen. Considering the interplay between the nervous system and intestinal immunity, which of the following outcomes would be MOST plausible following complete vagal denervation?

Decreased expression of lysozyme and defensins, potentially increasing susceptibility to bacterial dysbiosis. (D) Signup and view all the answers

A patient with advanced liver cirrhosis exhibits both ascites (accumulation of fluid in the peritoneal cavity) and esophageal varices (dilated veins in the esophagus). Which of the following hepatic functions is MOST directly compromised in this patient, contributing to these clinical manifestations?

Impaired synthesis of plasma proteins, leading to decreased oncotic pressure and fluid extravasation. (D) Signup and view all the answers

A novel drug selectively inhibits the basolateral Na+/K+ ATPase in pancreatic ductal cells. Which of the following consequences would MOST directly impact overall digestive physiology?

Reduced secretion of bicarbonate-rich fluid, impairing neutralization of gastric acid in the duodenum. (B) Signup and view all the answers

A patient presents with hypersecretion of gastric acid and rapid gastric emptying. If pharmacological intervention aims to selectively inhibit the endocrine pathway responsible, which of the following would be the MOST appropriate target, considering the intricate feedback loops governing gastric function?

A somatostatin analog to directly inhibit parietal cell activity and indirectly enhance secretin release to further suppress gastric acid secretion. (A) Signup and view all the answers

Following a partial gastrectomy, a patient experiences accelerated gastric emptying and subsequent duodenal acidification. Which compensatory mechanism is LEAST likely to mitigate the resultant disruption of intestinal homeostasis?

Compensatory down-regulation of vasoactive intestinal peptide (VIP) release to limit vasodilation and fluid secretion into the intestinal lumen, thereby reducing chyme volume. (D) Signup and view all the answers

A researcher is investigating the interplay between the central nervous system (CNS) and the enteric nervous system (ENS) in the regulation of gastric motility. To selectively activate the parasympathetic pathway influencing peristalsis without directly affecting gastric secretions, which of the following experimental interventions would be MOST appropriate?

Vagal nerve stimulation proximal to the nodose ganglion, coupled with a muscarinic receptor antagonist at the level of the gastric glands. (A) Signup and view all the answers

In a patient with chronic pancreatitis and diminished exocrine function, which hormonal replacement strategy would MOST effectively address both the impaired digestion and potential metabolic sequelae?

Supplementation with secretin and CCK analogs to restore pancreatic bicarbonate and enzyme output, coupled with exogenous lipase and protease. (B) Signup and view all the answers

A novel gastrointestinal peptide is discovered that potently inhibits gastric emptying, stimulates insulin release, and enhances satiety. Which of the following mechanisms is LEAST likely to contribute to its overall physiological effect?

Potentiation of vasoactive intestinal peptide (VIP) release, increasing blood flow to the gastric mucosa and facilitating nutrient absorption. (A) Signup and view all the answers

A researcher aims to develop a drug that selectively enhances the protective functions of the duodenum against acidic chyme without affecting gastric motility or acid secretion. Which of the following would be the MOST promising target for drug development?

A selective agonist of secretin receptors on pancreatic ductal cells to enhance bicarbonate secretion without affecting gastric function. (C) Signup and view all the answers

A patient presents with a rare genetic defect resulting in non-functional G cells. Understanding the interconnectedness of digestive hormonal regulation, which of the following compensatory mechanisms would be LEAST likely to occur?

Downregulation of somatostatin secretion in the gastric mucosa, leading to unopposed stimulation of parietal cells by other secretagogues. (A) Signup and view all the answers

During intense physical exercise, sympathetic nervous system activity predominates, influencing gastrointestinal function. Which of the following hormonal responses is LEAST likely to occur in this scenario?

Increased CCK release in response to mobilized fatty acids entering the duodenum, stimulating gallbladder contraction and enzyme secretion. (A) Signup and view all the answers

Flashcards

Types of Sensory Information

Includes mechanical, thermal, osmotic, and chemical signals.

CNS Afferent Pathway

Sensory information is conveyed to the CNS via afferent fibers of the Vagus nerve.

Parasympathetic Gut Nerves

Glossopharyngeal (IX), Facial (VII), Vagus, and Sacral nerves provide parasympathetic outflow to the gut.