1.
Which of the following statements is most accurate regarding metoclopraminde when it is used in low doses?
Correct Answer
E. Stimulates gastric contractions and increases peristalsis in the small intestine
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.
2.
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?
Correct Answer
B. Incomplete closure of the lateral folds
Explanation
Abdominal viscera protrude into amniotic cavity through body wall defect
3.
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?
Correct Answer
C. Descending colon
Explanation
Preganglionic parasympathetics supplied by pelvic splanchnic nerves (S2-S4)
Ascending colon = Preganglionic parasympathetics supplied by vagus nerve
4.
Which of the following should be avoided in patients taking clopidogrel?
Correct Answer
B. Omeprazole
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.
5.
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?
Correct Answer
B. The more affected family members the higher the recurrence risk
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.
6.
Of the following functions, which is not associated with the tissue shown?
Correct Answer
D. Synthesis and secretion of pepsinogen
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
7.
Which of the following statements about antacids that contain aluminum and magnesium is the LEAST valid?
Correct Answer
C. Heal duodenal ulcers more rapidly than does esomeprazole
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.
8.
PPI therapy is linked to:
Correct Answer
B. Cancer in rodents but not humans
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.
9.
Elderly women who have collagenous colitis:
Correct Answer
B. Virtually never have a pathogenic organism that causes the colitis.
Explanation
the cause of this colitis is unknown.
10.
Which of the following statements about antacids that contain aluminum and magnesium is the LEAST valid?
Correct Answer
C. Heal duodenal ulcers more rapidly than does esomeprazole
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.
11.
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.
Correct Answer
D. The female sib of a male proband
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.
12.
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:
Correct Answer
D. IgM can substitute for IgA in mucosa and can be actively transported across epithelium and released as a complex containing secretory component/J chain /the IgM pentamer, to carry out the same functions as secretory IgA.
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.
13.
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?
Correct Answer
D. Symptomatic management
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
14.
Bismuth subcitrate (peptobismol) is:
Correct Answer
D. Can promote healing of peptic ulcers
Explanation
Bismuth subcitrate (peptobismol) can promote healing of peptic ulcers.