A Quick Quiz For Medical Entrance Exams Preparation

1. The mucosal immune system is present in six or more human organs but faces huge challenges in carrying out its functions. These include:

Denying entry of micro-organisms to the body, despite an abundance of intra-luminal bacteria and viruses nearby

Distinguishing harmless from pathological micro-organisms, in order to make an immune response only when appropriate

Protecting a vast surface area, estimated to be the size of two tennis courts in the gut alone

All of the above

The correct answer is "All of the above" because the given challenges are all faced by the mucosal immune system. It needs to prevent the entry of micro-organisms into the body, differentiate between harmless and harmful micro-organisms, and protect a large surface area. These challenges are crucial for the proper functioning of the mucosal immune system in maintaining the body's overall immune response.

Explanation

The correct answer is "All of the above" because the given challenges are all faced by the mucosal immune system. It needs to prevent the entry of micro-organisms into the body, differentiate between harmless and harmful micro-organisms, and protect a large surface area. These challenges are crucial for the proper functioning of the mucosal immune system in maintaining the body's overall immune response.

2. A hard mass (a fecolith) in the ostium of a 27-year-old patient's appendix had led to a local infection (appendicitis). The initial pain from the infection was dull and difficult to localize, but the patient placed his hand in the periumbilical area to indicate the general area of discomfort. The region of the umbilicus receives its sensory supply from with of the following spinal nerves?

T7

T8

T10

T12

L1

The region of the umbilicus receives its sensory supply from the T10 spinal nerve. This is known as the dermatome of T10. The patient's indication of discomfort in the periumbilical area suggests that the infection and inflammation caused by the fecolith in the appendix has affected the sensory nerves originating from the T10 spinal nerve, resulting in pain in that specific region.

Explanation

The region of the umbilicus receives its sensory supply from the T10 spinal nerve. This is known as the dermatome of T10. The patient's indication of discomfort in the periumbilical area suggests that the infection and inflammation caused by the fecolith in the appendix has affected the sensory nerves originating from the T10 spinal nerve, resulting in pain in that specific region.

3. A 55-year-old man is admitted to the hospital with severe abdominal pain. Gastroscopy and CT scan examinations revealed a perforating ulcer in the posterior wall of the stomach. Where would peritonitis most likely develop initially?

Hepatorenal recess

Omental bursa (lesser sac)

Right subphrenic space

Left infracolic gutter

Fluids from the perforated gastric ulcer will eventually collect in the Hepatorenal recess by draining through the omental foramen, but the initial location of these fluids will be in the lesser sac

Explanation

Fluids from the perforated gastric ulcer will eventually collect in the Hepatorenal recess by draining through the omental foramen, but the initial location of these fluids will be in the lesser sac

4. Misoprostil is contraindicated in:

GERD

Duodenal ulcers

Diabetics

Heroin addicts

Reproductive women

Misoprostil is contraindicated in reproductive women because it is a medication used to induce labor and terminate pregnancies. It is not recommended for use in women who are pregnant or may become pregnant, as it can cause uterine contractions and potentially lead to miscarriage or other complications. Therefore, reproductive women should avoid using misoprostil.

Explanation

Misoprostil is contraindicated in reproductive women because it is a medication used to induce labor and terminate pregnancies. It is not recommended for use in women who are pregnant or may become pregnant, as it can cause uterine contractions and potentially lead to miscarriage or other complications. Therefore, reproductive women should avoid using misoprostil.

5. During surgery, you must excise the anterior rectus sheath between the xiphoid process and the umbilicus. In this region, the sheath is derived from the aponeurosis of the

External abdominal oblique only

Internal abdominal oblique only

External and internal abdominal oblique

Internal oblique and tranversus abdominis

Transversus abdominis only

The aponeurosis of the internal oblique splits so that one half of it contributes to the anterior layer of the rectus sheath and the other half contributes to the posterior layer.

Explanation

The aponeurosis of the internal oblique splits so that one half of it contributes to the anterior layer of the rectus sheath and the other half contributes to the posterior layer.

6. 48 year old Caucasian female presents to a gastroenterologist with progressive dysphagia over 2 years. She reports problems with foods of all consistencies, as well as some liquids. She has heartburn symptoms and intermittent regurgitation of undigested food, and has lost 15 pounds over the past 6 months. She takes no medications and has no other medical problems. Upper endoscopy is performed and is normal. Barium swallow is below: Assuming esophageal motility studies confirm the diagnosis, which of the following would be the most appropriate treatment option in this patient?

Nitroglycerin

Calcium channel blocker

Surgical myotomy of the lower esophageal sphincter

Botulinum toxin injection into the upper esophageal sphincter

A and B

The patient's symptoms, including progressive dysphagia, heartburn, regurgitation, and weight loss, are consistent with achalasia, a disorder characterized by impaired esophageal motility and dysfunction of the lower esophageal sphincter (LES). The normal upper endoscopy suggests that there are no structural abnormalities causing the symptoms. Surgical myotomy of the LES, which involves cutting the muscle fibers of the LES to relieve the obstruction, is the most appropriate treatment option for achalasia. Nitroglycerin and calcium channel blockers are not effective in treating achalasia. Botulinum toxin injection into the upper esophageal sphincter is used for a different condition called cricopharyngeal dysfunction, which is not mentioned in the patient's presentation. Therefore, the correct answer is surgical myotomy of the lower esophageal sphincter.

Explanation

The patient's symptoms, including progressive dysphagia, heartburn, regurgitation, and weight loss, are consistent with achalasia, a disorder characterized by impaired esophageal motility and dysfunction of the lower esophageal sphincter (LES). The normal upper endoscopy suggests that there are no structural abnormalities causing the symptoms. Surgical myotomy of the LES, which involves cutting the muscle fibers of the LES to relieve the obstruction, is the most appropriate treatment option for achalasia. Nitroglycerin and calcium channel blockers are not effective in treating achalasia. Botulinum toxin injection into the upper esophageal sphincter is used for a different condition called cricopharyngeal dysfunction, which is not mentioned in the patient's presentation. Therefore, the correct answer is surgical myotomy of the lower esophageal sphincter.

7. The fluorescent nucleotide analog bromodeoxyuridine (BrdU) has been used widely to label cells engaged in DNA synthesis and thereby identify regions in tissues where cell proliferation is occurring. If you apply BrdU labeling to the gastrointestinal tract and sample tissues at increasing times for examination by fluorescence microscopy, which one of the following outcomes might you expect to observe?

No labeling in the esophageal mucosal epithelium because it doesn’t undergo turnover

Labeling of chief cells at the base of gastric glands in the stomach but not labeling of surface mucous cells

Labeling in Peyer’s patches but not in the mucosal epithelium of the ileum

Labeling only on villi in the colon

All mucosal epithelia in the GI tract undergo turnover
Stem cells in the Small intestine are concentrated toward the base of mucosal glands (crypts). As cells mature, they progressively move upward toward the tips of villi. Thus labeling is observed first in crypts and then on villi.

Explanation

All mucosal epithelia in the GI tract undergo turnover
Stem cells in the Small intestine are concentrated toward the base of mucosal glands (crypts). As cells mature, they progressively move upward toward the tips of villi. Thus labeling is observed first in crypts and then on villi.

8. A 68 year-old man is evaluated for chronic epigastric discomfort, heartburn, and diarrhea of 4 years' duration. His weight has been stable during this time period. The patient has no significant medical history and takes no medications. On physical examination, there is mild epigastric tenderness but no rebound or guarding. Rectal examination reveals brown stool that is hemoccult positive. Laboratory studies reveal a hemoglobin of 12.4 g/dL with a mean corpuscular volume of 73. Test for serum Helicobacter pylori antibody is negative. EGD shows prominent gastric folds, mild linear erosions, and multiple ulcers in the first and second portions of the duodenum. Which of the following is the most appropriate next step in the evaluation of this patient?

CT scan of the abdomen and pelvis

Abdominal ultrasound

Measurement of serum gastrin

Flexible sigmoidoscopy

The patient presents with dyspepsia, diarrhea and microcytic anemia. He does not have typical risk factors for peptic ulcer disease (Hp, NSAIDs). Ulceration beyond the duodenal bulb is unusual and should trigger thoughts of Zollinger-Ellison syndrome, particularly in this clinical scenario. A serum gastrin level is the correct initial test for evaluation of ZE syndrome.

Explanation

The patient presents with dyspepsia, diarrhea and microcytic anemia. He does not have typical risk factors for peptic ulcer disease (Hp, NSAIDs). Ulceration beyond the duodenal bulb is unusual and should trigger thoughts of Zollinger-Ellison syndrome, particularly in this clinical scenario. A serum gastrin level is the correct initial test for evaluation of ZE syndrome.

9. Which of the following statements best describes gastroesophageal reflux disease (GERD)?

Of all GI disorders GERD has the most economic impact

Elderly patients tend to have more serious manifestations of GERD

Esophageal adenocarcinoma can be associated with GERD

President Clinton's hoarseness was likely due to GERD

All of the above

All of the statements provided accurately describe different aspects of gastroesophageal reflux disease (GERD). The first statement highlights the economic impact of GERD compared to other gastrointestinal disorders. The second statement indicates that elderly patients often experience more severe symptoms of GERD. The third statement suggests a potential association between GERD and esophageal adenocarcinoma. Lastly, the fourth statement implies that GERD could have been the cause of President Clinton's hoarseness. Therefore, all of the statements are correct in describing GERD.

Explanation

All of the statements provided accurately describe different aspects of gastroesophageal reflux disease (GERD). The first statement highlights the economic impact of GERD compared to other gastrointestinal disorders. The second statement indicates that elderly patients often experience more severe symptoms of GERD. The third statement suggests a potential association between GERD and esophageal adenocarcinoma. Lastly, the fourth statement implies that GERD could have been the cause of President Clinton's hoarseness. Therefore, all of the statements are correct in describing GERD.

10. A 48 year old female presents to your office with 9 days of bloody diarrhea. Her symptoms started with diarrhea nausea vomiting and fever to 38.7 C. She has no history of inflammatory bowel disease. One of her coworkers also developed nausea and diarrhea around the same time her symptoms began. You send stool cultures which come back positive for salmonella. If you were to take biopsies of the colonic mucosa, you are most likely to see an increase in which of the following cells:

T-lymphocytes

Dendritic cells

Macrophages

Neutrophils

Plasma cells

T-lymphocytes refer to GI immunology camtasia.

Neutrophils are increased in acute inflammation

Explanation

T-lymphocytes refer to GI immunology camtasia.

Neutrophils are increased in acute inflammation

11. The same patient was referred to a gastroenterologist after persistence of symptoms despite therapy with a PPI. His esophageal biopsies confirmed the diagnosis of EoE. Family history revealed his father had struggled with dysphagia for years as a young man that spontaneously resolved. The patient's mother and sister both have eczema and asthma. The patient had a history of milk protein allergy as an infant. At this point the pediatrician should:

Start the patient on a strict diet eliminating all dairy and beef

Consider referral to a Pediatric Allergist for evaluation for possible environmental and food exposures that may be contributing to EoE

Start the patient on 2mg/kg/day of methylprednisolone x 2 months with slow taper

Roughly 50-80% of patients with EoE will have either a personal history or strong family history of atopy (allergic rhinitis, eczema, asthma). Both human and animal data suggest a strong association with a Th2 profile and the majority of patients will improve on am allergen free diet. Roughly 2/3 of patients with EoE will have a positive skin prick test to at least one food allergen. The most common antigens include cow milk, egg, peanut, soy and wheat. At present, most patients will benefit from an allergy evaluation as removal of skin prick "positive" antigens will lead to clinical improvement of roughly 75% of patients.

Explanation

Roughly 50-80% of patients with EoE will have either a personal history or strong family history of atopy (allergic rhinitis, eczema, asthma). Both human and animal data suggest a strong association with a Th2 profile and the majority of patients will improve on am allergen free diet. Roughly 2/3 of patients with EoE will have a positive skin prick test to at least one food allergen. The most common antigens include cow milk, egg, peanut, soy and wheat. At present, most patients will benefit from an allergy evaluation as removal of skin prick "positive" antigens will lead to clinical improvement of roughly 75% of patients.

12. A 24 year old nurse presents with 8 weeks of progressive bloody diarrhea. Stool studies are negative for enteric pathogens. She undergoes colonoscopy, which shows active inflammation throughout the colon. Biopsies were obtained. In biopsy specimens from the colon, the most important finding that distinguishes Crohn's disease from ulcerative colitis is:

Crypt abcesses

Lymphoid aggregates

Eosinophils

Granulomas

Ulceration

Explanation: both ulcerative colitis and Crohn’s disease can have crypt abscesses, lymphoid aggregates, eosinophils, and ulceration. Granulomas are found in Crohn’s, not ulcerative colitis..

Explanation

Explanation: both ulcerative colitis and Crohn’s disease can have crypt abscesses, lymphoid aggregates, eosinophils, and ulceration. Granulomas are found in Crohn’s, not ulcerative colitis..

13. All of the following are true of the cells marked by the arrows EXCEPT:

They can be found in the esophagus, stomach, small intestine, and large intestine.

They facilitate the peristalsis of the gut

They are derived from the stem cells that are located in crypts of Lieberkuhn

They are very active in protein synthesis

They are absent in the distal colon in Hirschsprung’s disease

The arrows are pointing to ganglionic neurons from the myenteric (Auerbach ‘s) plexus, part of the enteric nervous system that is located between the two layers of muscle cells making up the muscularis externa of the gut wall (note the two layers of smooth msucle in this image). Only cell types in the epithelium of the mucosa of the small and large intestine are derived from the stem cells located in the crypts of Liberkuhn.

Explanation

The arrows are pointing to ganglionic neurons from the myenteric (Auerbach ‘s) plexus, part of the enteric nervous system that is located between the two layers of muscle cells making up the muscularis externa of the gut wall (note the two layers of smooth msucle in this image). Only cell types in the epithelium of the mucosa of the small and large intestine are derived from the stem cells located in the crypts of Liberkuhn.

14. Which of the following is a complication of chronic reflux esophagitis?

Squamous metaplasia

Esophageal varices

Malt lymphoma

Dysplasia

Hiatal hernia

Dysplasia is correct because it precedes adenocarcinoma.

Explanation

Dysplasia is correct because it precedes adenocarcinoma.

15. A three week old male presents to your clinic with projectile vomiting and weight loss. Following surgery, the baby makes a complete recovery. A family history reveals that the baby's maternal uncle also had a pyloric stenosis. No other cases in the family were noted. What is the most likely mode of inheritance in this family?

Autosomal dominant

Autosomal recessive

X-linked recessive

Multifactorial

Multifactorial This is a typical pattern of a multifactorial disorder – there may be some other affected family members, but there will not be a typical single gene inheritance pattern.

Explanation

Multifactorial This is a typical pattern of a multifactorial disorder – there may be some other affected family members, but there will not be a typical single gene inheritance pattern.