Block 6 GI histo Univ of Virginia w expl prt 2

1. Which of the following statements about antacids that contain aluminum and magnesium is the LEAST valid?

May slow gastric emptying

May cause mild alkalosis due to excess plasma bicarbonate

Heal duodenal ulcers more rapidly than does esomeprazole

Can cause constipation

May cause diarrhea in high doses

The statement that antacids containing aluminum and magnesium heal duodenal ulcers more rapidly than esomeprazole is the least valid. While antacids can provide temporary relief from symptoms of ulcers, they do not actually heal the ulcers. Esomeprazole, on the other hand, is a proton pump inhibitor that reduces stomach acid production and promotes ulcer healing. Therefore, the statement is incorrect.

Explanation

The statement that antacids containing aluminum and magnesium heal duodenal ulcers more rapidly than esomeprazole is the least valid. While antacids can provide temporary relief from symptoms of ulcers, they do not actually heal the ulcers. Esomeprazole, on the other hand, is a proton pump inhibitor that reduces stomach acid production and promotes ulcer healing. Therefore, the statement is incorrect.

2. A 19-year-old male is admitted to the hospital after a violent automobile collision. An MRI examination reveals that the spinal cord has been transected at the L4 level. Which of the following portions of the intestine will most predictably lose parasympathetic innervation from the central nervous system?

Ascending colon

Cecum

Descending colon

Ileum

Preganglionic parasympathetics supplied by pelvic splanchnic nerves (S2-S4)
Ascending colon = Preganglionic parasympathetics supplied by vagus nerve

Explanation

Preganglionic parasympathetics supplied by pelvic splanchnic nerves (S2-S4)
Ascending colon = Preganglionic parasympathetics supplied by vagus nerve

3. Bismuth subcitrate (peptobismol) is:

Organic stool softener; promotes colonic motility

Poorly absorbed; used for rapid effect before bowel surgery

Poorly absorbed opioid; slows transit of intestinal contents

Can promote healing of peptic ulcers

Promotes secretion of H2O into the colon; chronic use can produce "cathartic colon"

Bismuth subcitrate (peptobismol) can promote healing of peptic ulcers.

Explanation

Bismuth subcitrate (peptobismol) can promote healing of peptic ulcers.

4. Which of the following statements about antacids that contain aluminum and magnesium is the LEAST valid?

May slow gastric emptying

May cause mild alkalosis due to excess plasma bicarbonate

Heal duodenal ulcers more rapidly than does esomeprazole

Can cause constipation

May cause diarrhea in high doses

This statement is the least valid because antacids that contain aluminum and magnesium do not have the ability to heal duodenal ulcers more rapidly than esomeprazole. Antacids provide temporary relief from symptoms by neutralizing stomach acid, but they do not have the same healing properties as medications like esomeprazole, which reduce the production of stomach acid and allow the ulcers to heal over time.

Explanation

This statement is the least valid because antacids that contain aluminum and magnesium do not have the ability to heal duodenal ulcers more rapidly than esomeprazole. Antacids provide temporary relief from symptoms by neutralizing stomach acid, but they do not have the same healing properties as medications like esomeprazole, which reduce the production of stomach acid and allow the ulcers to heal over time.

5. Of the following functions, which is not associated with the tissue shown?

Secretion of mucus and polypeptide hormones

Production of chylomicrons and delivery to the lymph

Hydrolysis of peptides and absorption of amino acids

Synthesis and secretion of pepsinogen

This light micrograph shows the duodenum, the first portion of the large intestine. The duodenum can be identified by the prominant submucosal glands, called the Brunner’s glands. The jejunum and ileum do not have submucosal glands. Pepsinogen is synthesized and secreted by the glands of the stomach and not by the small intestine. Hence, this is an incorrect statement about the duodenum
Goblet cells in the epithelium covering the mucosa of the duodenum secrete mucus. Enteroendocrine cells in the epithelium of the mucosa secrete hormones

Explanation

This light micrograph shows the duodenum, the first portion of the large intestine. The duodenum can be identified by the prominant submucosal glands, called the Brunner’s glands. The jejunum and ileum do not have submucosal glands. Pepsinogen is synthesized and secreted by the glands of the stomach and not by the small intestine. Hence, this is an incorrect statement about the duodenum
Goblet cells in the epithelium covering the mucosa of the duodenum secrete mucus. Enteroendocrine cells in the epithelium of the mucosa secrete hormones

6. Which of the following statements is most accurate regarding metoclopraminde when it is used in low doses?

Decreases gastric acid secretion

Blocks cholinergic receptors in the stomach wall

Decreases the tone of the lower esophageal sphincter (LES)

Acts as an antagonist of 5-HT in myenteric plexuses

Stimulates gastric contractions and increases peristalsis in the small intestine

Metoclopramide, when used in low doses, stimulates gastric contractions and increases peristalsis in the small intestine. This means that it enhances the movement of food through the digestive system, promoting digestion and preventing issues such as delayed gastric emptying. The other statements are incorrect as metoclopramide does not decrease gastric acid secretion, block cholinergic receptors in the stomach wall, decrease the tone of the lower esophageal sphincter, or act as an antagonist of 5-HT in myenteric plexuses.

Explanation

Metoclopramide, when used in low doses, stimulates gastric contractions and increases peristalsis in the small intestine. This means that it enhances the movement of food through the digestive system, promoting digestion and preventing issues such as delayed gastric emptying. The other statements are incorrect as metoclopramide does not decrease gastric acid secretion, block cholinergic receptors in the stomach wall, decrease the tone of the lower esophageal sphincter, or act as an antagonist of 5-HT in myenteric plexuses.

7. One in 500 persons is born without the ability to make IgA, yet few have chronic mucosal infections over their lifetime. The most likely reason why these individuals are not persistently ill is best answered by which statement:

The prominent IgA isotype in mucosa (IgA2) is not affected in the deficiency

Secretary IgA, as the most plentiful immunoglobuin in the body, is diminished but not absent in the deficiency

In individuals born without the ability to make IgA, IgM can substitute for IgA in the mucosa. IgM can be actively transported across the epithelium and released as a complex containing secretory component/J chain/the IgM pentamer, allowing it to carry out the same functions as secretory IgA. This explains why these individuals are not persistently ill despite the deficiency in IgA production.

Explanation

In individuals born without the ability to make IgA, IgM can substitute for IgA in the mucosa. IgM can be actively transported across the epithelium and released as a complex containing secretory component/J chain/the IgM pentamer, allowing it to carry out the same functions as secretory IgA. This explains why these individuals are not persistently ill despite the deficiency in IgA production.

8. As part of a population study of neural tube defects you collect numerous pedigrees of families with an affected member. As part of the analysis, you determine the recurrence risk for various types of families and find the following: Number of Affected Children Recurrence risk 1 3% 2 12% 3 21% Which of the following characteristics of multifactorial inheritance describes this?

The more severe the phenotype the higher the recurrence risk

The more affected family members the higher the recurrence risk

The recurrence risk is highest in first degree relative

The recurrence risk is highest in families who have affected individuals of the less susceptible sex

This data concerns the number of affected children in the collected families and is consistent with the characteristic of multifactorial disorders that the recurrence risk increases with increasing numbers of affected individuals. Although the other statements are true, they are not addressed in this data.

Explanation

This data concerns the number of affected children in the collected families and is consistent with the characteristic of multifactorial disorders that the recurrence risk increases with increasing numbers of affected individuals. Although the other statements are true, they are not addressed in this data.

9. Which of the following should be avoided in patients taking clopidogrel?

Ranitidine

Omeprazole

Bismuth

Cimetidine

Al(OH)3

Omeprazole should be avoided in patients taking clopidogrel. Omeprazole is a proton pump inhibitor (PPI) that inhibits the enzyme CYP2C19, which is responsible for metabolizing clopidogrel into its active form. By inhibiting this enzyme, omeprazole reduces the effectiveness of clopidogrel, potentially leading to decreased antiplatelet activity and increased risk of cardiovascular events. Therefore, it is recommended to use alternative medications such as ranitidine or famotidine, which do not inhibit CYP2C19, in patients taking clopidogrel.

Explanation

Omeprazole should be avoided in patients taking clopidogrel. Omeprazole is a proton pump inhibitor (PPI) that inhibits the enzyme CYP2C19, which is responsible for metabolizing clopidogrel into its active form. By inhibiting this enzyme, omeprazole reduces the effectiveness of clopidogrel, potentially leading to decreased antiplatelet activity and increased risk of cardiovascular events. Therefore, it is recommended to use alternative medications such as ranitidine or famotidine, which do not inhibit CYP2C19, in patients taking clopidogrel.

10. You are conducting a study of idiopathic scoliosis (curvature of the spine). In its isolated form, scoliosis appears to be a multifactorial disorder. It is much more common in females than males. Select the individual described below who is at the highest risk for scoliosis. You may assume that there is no other family history.

The male sib of a male proband

The female sib of a female proband

The male sib of a female proband

The female sib of a male proband

Females are more easily affected with scoliosis. The threshold model for multifactorial inheritance would assume that families with male proband have a higher liability for having affected offspring; empiric data have confirmed this. Since females are more easily affected it is the female sib of a male proband who has the highest risk.

Explanation

Females are more easily affected with scoliosis. The threshold model for multifactorial inheritance would assume that families with male proband have a higher liability for having affected offspring; empiric data have confirmed this. Since females are more easily affected it is the female sib of a male proband who has the highest risk.

11. A 30-year-old woman is evaluated for a 9-month history of cramping periumbilical discomfort that is relieved by defecation; the discomfort is sometimes accompanied by bloating. The stool is often loose or watery. She has not had fever, chills, or weight loss. The patient is otherwise healthy and takes no medications; there is no family history of gastrointestinal disease. On physical examination, the patient is afebrile; the blood pressure is 105/70 mm Hg, the pulse rate is 72/min, the respiration rate is 14/min, and the BMI is 23. The abdomen is soft and not tender or distended; the stool is brown and negative for occult blood. Complete blood count and serum biochemistry studies, including liver studies, vitamin B₁₂, vitamin D, and thyroid-stimulating hormone, are normal. Which of the following is the most appropriate management for this patient?

Colonoscopy

CT enterography

Gluten-free diet

Symptomatic management

EGD

This patient meets symptom criteria for irritable bowel syndrome and has no alarm symptoms. Celiac screening may be done, but no additional workup should be done in this setting

Explanation

This patient meets symptom criteria for irritable bowel syndrome and has no alarm symptoms. Celiac screening may be done, but no additional workup should be done in this setting

12. Ultrasound examinations of a male fetus in the seventh month of gestation indicate a defect on his right side, lateral to the median plane, in which the viscera protrude into the amniotic cavity. Which of the following conditions will most likely explain these findings?

Failure of physiological herniation to return to the abdominal cavity

Incomplete closure of the lateral folds

Failure of the pleuroperitoneal folds to fuse with the septum transversum

Failure of the vitelline duct to degenerate

Non-rotation of the midgut

Abdominal viscera protrude into amniotic cavity through body wall defect

Explanation

Abdominal viscera protrude into amniotic cavity through body wall defect

13. Elderly women who have collagenous colitis:

Often have lower GI tract hemorrhage.

Virtually never have a pathogenic organism that causes the colitis.

Typically have symptoms that resolve over a two week period.

Have deposition of collagen in the muscularis propria (muscularis externa)

Usually have involvement of the proximal small intestine.

the cause of this colitis is unknown.

Explanation

the cause of this colitis is unknown.

14. PPI therapy is linked to:

Cancer in rodents and humans

Cancer in rodents but not humans

Prolonged QT syndrome

Cardiac arrhythmias

Gastroparesis

The correct answer is "cancer in rodents but not humans." This means that studies have shown a link between PPI therapy and the development of cancer in rodents, but there is no evidence to suggest that the same link exists in humans. It is important to note that this answer does not imply that PPI therapy is completely safe for humans, but rather that the specific link to cancer has only been observed in rodents.

Explanation

The correct answer is "cancer in rodents but not humans." This means that studies have shown a link between PPI therapy and the development of cancer in rodents, but there is no evidence to suggest that the same link exists in humans. It is important to note that this answer does not imply that PPI therapy is completely safe for humans, but rather that the specific link to cancer has only been observed in rodents.

Block 6 GI Histo Univ Of VirGInia W Expl Prt 2

1. Which of the following statements about antacids that contain aluminum and magnesium is the LEAST valid?

2.

What first name or nickname would you like us to use?

3. Bismuth subcitrate (peptobismol) is:

4. Which of the following statements about antacids that contain aluminum and magnesium is the LEAST valid?

5. Of the following functions, which is not associated with the tissue shown?

6. Which of the following statements is most accurate regarding metoclopraminde when it is used in low doses?

7. One in 500 persons is born without the ability to make IgA, yet few have chronic mucosal infections over their lifetime. The most likely reason why these individuals are not persistently ill is best answered by which statement:

9. Which of the following should be avoided in patients taking clopidogrel?

12. Ultrasound examinations of a male fetus in the seventh month of gestation indicate a defect on his right side, lateral to the median plane, in which the viscera protrude into the amniotic cavity. Which of the following conditions will most likely explain these findings?

13. Elderly women who have collagenous colitis:

14. PPI therapy is linked to: