1.
Dr Mallik (Ext 6479) 10am
A known patient of irregularly treated but persistent achalasia for about last the 20 years presents with recent onset of worsening of dysphagia. For the last 5 years he did not attend any clinic. What is your investigation of choice?
Correct Answer
A. Upper GI endoscopy
Explanation
The investigation of choice in this case would be Upper GI endoscopy. This procedure allows for direct visualization of the esophagus and can help identify any structural abnormalities or blockages that may be causing the worsening dysphagia. It can also help assess the severity of the achalasia and guide further treatment options. Barium swallow and video fluoroscopy can also provide valuable information, but they are not as effective in directly visualizing the esophagus as upper GI endoscopy. Esophageal manometry can help assess the function of the esophagus, but it may not provide as much information about the cause of the worsening dysphagia. X-ray chest and abdomen may not provide enough detail to identify the cause of the dysphagia.
2.
Dr White (Ext6330) 10:05am
As part of a diagnostic test, a gastroenterologist uses an endoscope to deliver a bolus of dilute acid into the distal esophagus. The bolus is sufficient to cause esophageal dilatation. In a normal individual, the bolus will be cleared from the esophagus predominantly by which of the following?
Correct Answer
E. Secondary peristalsis
Explanation
Peristalsis in the two functional regions of the Esophagus:
In the proximal region where striated muscle predominates, a centrally coordinated sequential firing pattern of vagal motor neurons (whose cell bodies are in the nucleus ambiguus) project to progressively distal areas in the esophagus coordinates primary peristalsis.
In the more distal (smooth muscle) part of the esophagus, co-ordination involves activity of vagal inhibitory (VIP/NO) and excitatory pathways (Ach) with myenteric circuits.
Upon swallowing, inhibitory pathway neurons in the caudal DMN are activated first – which causes relaxation of all parts of the esophagus. As this relaxation subsides, there is sequential activation of excitatory neurons in the rostral DMN, that causes a peristaltic contraction.
“Secondary peristalsis” does not require a swallow with the associated pharyngeal events to initiate it. It is activated through local peristaltic reflexes caused by distension. Such behavior may be elicited by food particles “left behind” after a primary peristaltic wave has passed, or it might be caused by refluxed stomach contents. Secondary peristalsis is entirely normal, it occurs a number of times during feeding – and the individual is entirely unaware of it.
(Slide 30 gen princ GI phys-White)
3.
A scientist genetically engineers a mouse to lose expression of S cells. Compared with a normal animal, which of the following would be expected to be increased in the mutant mouse?
Correct Answer
C. Susceptibility to duodenal erosions and ulcerations
Explanation
Control of secretin & bicarbonate secretion:
The ducts of the pancreas can be considered the effector arm of a pH regulatory system designed to respond to luminal acid in the small intestine and secrete just enough bicarbonate to restore pH to neutrality. This regulatory function also requires mechanisms to sense luminal pH and convey this information to the pancreas, as well as other epithelia (e.g., biliary ductules and the duodenal epithelium itself) capable of secreting bicarbonate. The pH-sensing mechanism is embodied in specialized endocrine cells localized within the small intestinal epithelium, known as S cells. When luminal pH falls below 4.5, S cells are triggered to release secretin, presumably in direct response to protons. No other releasing factors for secretin are known. The components of this regulatory loop constitute a self-limiting system. Thus, as secretin evokes secretion of bicarbonate, pH in the small intestinal lumen will rise and the signal for release of secretin from S cells will be terminated.
(slide 10 small intest colon-WHITE)
4.
During dinner you notice that you have an intense impulse to defecate. Where in the gastrointestinal tract does the sensory signal that triggers this sensation take place?
Correct Answer
D. Stomach
Explanation
Control:
Rectal distension initiates the rectosphincteric reflex, in which the internal anal sphincter initially relaxes and the pressure recorded in the anal lumen decreases. As fecal material moves down into the upper part of the anal canal, it initiates the urge to defecate. The sensation of fullness of the rectum and the desire to defecate often follows ingestion of a meal (gastro-colic reflex) or on getting out of bed in the morning (ortho-colic reflex ).If the urge to defecate is resisted, by voluntary contraction of the external sphincter, the sensation subsides as the rectal wall relaxes to reduce rectal pressure and the feces are temporarily accommodated in the rectum.
If defecation is desired, both the internal and external sphincters relax. This, coordinated with voluntary acts of straining (previous slide) in conjunction with involuntary contractions of the left colon and rectum expel the feces.
Frequency of defecation as well as the time of day that defecation is performed is largely a matter of habit. In healthy individuals it is between five and seven times a week.
(Slide 55 smll intest&colon-White)
5.
In a laboratory experiment, galactose absorption was studied under physiological conditions in a segment of jejunum isolated from human intestine and maintained in a gut bath. The rate of galactose absorption was determined initially at a sub-maximal rate. Which of the following interventions would increase the rate of absorption of galactose?
Correct Answer
B. Absorption would be increased by the addition of NaCl to the luminal fluid
Explanation
Adding NaCl to the luminal fluid would increase the rate of galactose absorption. This is because NaCl increases the osmotic gradient, which drives the movement of galactose across the intestinal epithelium. The presence of NaCl in the luminal fluid would create a higher concentration of solutes outside the intestinal cells, causing water to move out of the cells and creating a favorable environment for galactose absorption.
6.
A patient with a history of gastroesophageal reflux disease has been treated chronically with a proton pump inhibitor. Compared with a normal individual, the patient will be at increased risk of which of the following?
Correct Answer
D. Enteric infections
Explanation
Stomach Acid is one of the major defense mechanism of the GI tract.
7.
A patient undergoes surgery which involved the removal of a portion of the distal ileum. In this patient, what will be the direct consequence on bile acid metabolism or turnover?
Correct Answer
E. There will be increased synthesis by hepatocytes
Explanation
The removal of a portion of the distal ileum will result in increased synthesis of bile acids by hepatocytes. The distal ileum is responsible for the reabsorption of bile acids, so its removal will lead to decreased reabsorption and increased synthesis of bile acids by the liver. This is a compensatory mechanism to maintain adequate levels of bile acids in the body.
8.
Dr Charyk (Ext 6328) 10:10am
You are seeing a patient with chronic dyspepsia who comes in because his symptoms have been much worse recently, and he has felt very poorly the past 24 hours. He looks pale, worried, weak, and ill. Which of the following physical exam/lab tests would be most helpful in determining if he is experiencing an active GI bleed?
Correct Answer
B. Vital signs
Explanation
this is just a process of elimination, as none of the other choices would tell you if he was actively bleeding internally. Coaguopathy would only tell you if his blood was able to clot
(this was not covered in the lecture specifically, but the presentation of this case was a very extensive HPI)
9.
The breath test used to diagnose lactose intolerance:
Correct Answer
D. Relies on the presence of normal amounts of commensal colon bacteria, so recent use of antibiotics can cause a false negative result
Explanation
The breath test used to diagnose lactose intolerance relies on the presence of normal amounts of commensal colon bacteria. These bacteria are responsible for breaking down lactose in the colon, which produces hydrogen gas that can be measured in the breath. If a patient has recently taken antibiotics, it can disrupt the normal bacterial flora in the colon, leading to a decrease in hydrogen production and potentially causing a false negative result on the breath test.
10.
Mr. Bill had a large peptic ulcer several years ago which was located in the region of the pyloric channel, and which healed with a lot of scarring, resulting in a marked narrowing of the gastric outlet. His chronic symptoms are most likely to mimic those of:
Correct Answer
B. Gastroparesis
Explanation
Gastroparesis, also called delayed gastric emptying, is a medical condition consisting of a paresis (partial paralysis) of the stomach, resulting in food remaining in the stomach for a longer period of time than normal. Normally, the stomach contracts to move food down into the small intestine for digestion. The vagus nerve controls these contractions. Gastroparesis may occur when the vagus nerve is damaged and the muscles of the stomach and intestines do not work normally. Food then moves slowly or stops moving through the digestive tract.
Chronic gastroparesis can also be caused by other types of damage to the vagus nerve, such as abdominal surgery. Heavy smoking of cigarettes is also a plausible cause since smoking causes damage to the stomach lining.
Gastroparesis sufferers are disproportionately female. One possible explanation for this finding is that women have an inherently slower stomach emptying time than men. A hormonal link has also been suggested, as gastroparesis symptoms tend to worsen the week before menstruation, when progesterone levels are highest. Neither theory has been proven definitively.
(wikepedia)
11.
Dr Dhiman (Ext 6482) 10:15am
Which of the following muscle of the anterior abdominal wall arises along the inguinal ligament and iliac crest, whose fibers travel upward and medially to insert in the midline at the linea alba to the lower ribs?
Correct Answer
C. Internal oblique
Explanation
The correct answer is Internal oblique. The Internal oblique muscle arises along the inguinal ligament and iliac crest. Its fibers travel upward and medially to insert in the midline at the linea alba to the lower ribs. This muscle is part of the anterior abdominal wall and is responsible for flexing and rotating the trunk, as well as compressing the abdominal contents.
12.
A large tumor mass impinges on the splenic artery and its branches. Branches of which of the following arteries would most likely be affected by the pressure on the splenic artery?
Correct Answer
C. Short gastric
Explanation
A large tumor mass impinging on the splenic artery would most likely affect the branches of the artery that are in close proximity to it. The short gastric arteries are branches of the splenic artery that supply blood to the fundus and upper part of the greater curvature of the stomach. Therefore, the pressure on the splenic artery would most likely affect the short gastric arteries, potentially compromising blood flow to the stomach in that area.
13.
A 34-year-old man reached hospital after a fall from a motor bike. His x-ray shows fracture of the left ribs, 9th and 10th.
Which of the following organs would most likely get damage?
Correct Answer
B. Spleen
Explanation
The spleen is located on the left side of the abdomen, near the lower ribs. A fracture of the left ribs, specifically the 9th and 10th ribs, suggests that the impact of the fall was on the left side of the body. Given the proximity of the spleen to this area, it is likely that the spleen would be at risk of damage in this scenario.
14.
The deep inguinal ring is an evagination of which of the following layers?
Correct Answer
A. Transversalis fascia
Explanation
The deep inguinal ring is an evagination of the transversalis fascia. The transversalis fascia is a layer of connective tissue that lines the inner surface of the abdominal wall. It plays a role in providing support and protection to the organs in the abdominal cavity. The deep inguinal ring is a small opening in the transversalis fascia through which structures like the spermatic cord or round ligament of the uterus pass through. This allows them to travel from the abdomen to the inguinal canal.
15.
Dr Buxbaum (Ext 6429)10:25am
The DRI of Vitamin A for an 18a old | is: EAR 625ag/d, RDA 900ag/d and UL 2800ag/d. A patient of that group taking on average 950ag/d will suffer from symptoms of
Correct Answer
B. Deficiency with a probability of about 2%
Explanation
The question states that the patient is taking an average of 950ag/d of Vitamin A, which is higher than the RDA (900ag/d) but lower than the UL (2800ag/d). Since the patient's intake is above the RDA, it is unlikely that they will suffer from a deficiency. However, since their intake is below the UL, the probability of poisoning is low. Therefore, the most likely outcome is a deficiency with a probability of about 2%.
16.
A.B. is on chitosan to help him reduce weight. He may have to supplement his diet with which of the following compounds?
Correct Answer
E. E
Explanation
Since A.B. is on chitosan to help him reduce weight, it is likely that he needs to supplement his diet with a compound that aids in weight loss. Among the given options, compound E is the most suitable choice as it may have properties that support weight reduction.
17.
Dr Yin (Ext 6292) Lecturing
A transition from simple columnar epithelium with simple tubular glands (predominant cell type is goblet) to non-keratinized stratified squamous epithelium is revealed in a histological slide. The specimen is taken from one location on the GI tract. Based on the observation, which part of GI tube is under examination?
Correct Answer
C. Pectinate line
Explanation
The transition from simple columnar epithelium with simple tubular glands to non-keratinized stratified squamous epithelium suggests that the specimen is taken from the junction of the esophagus and cardia of the stomach. The pectinate line refers to the junction between the rectum and the anal canal, which is not relevant to the observation. The junction of the pylorus and duodenum, the junction of the excretory duct of salivary glands and oral cavity, and the junction of the sigmoid colon and rectum are also not consistent with the observed transition.
18.
Periodontal ligaments are derived from
Correct Answer
D. Neural crest
Explanation
except for enamel, the tooth and its associated structures (odontoblasts,dentin, cementoblast, cementum, Periodontal ligaments, c.t. of the gingiva, alveolus) are derived from Neural Crest Cells. (46minute mark of mediasite on GI&oral cavity- Yin)
19.
An ideal hepatocyte stacked in a hepatic cord is being viewed schematically. Four sides of this hepatocyte abut the adjoining hepatocytes, and the other two sides of this hepatocyte are left facing_____ directly.
Correct Answer
E. Space of Disse
Explanation
The Space of Disse is the correct answer because it is the space located between the hepatocytes and the hepatic sinusoids. It is a narrow space where blood flows and allows for the exchange of substances between the blood and the hepatocytes. The hepatocytes on four sides abut the adjoining hepatocytes, while the other two sides face the Space of Disse directly.
20.
Dr Adebiyi (Ext6230) PBL
What type of cell is the M cell found in the intestinal wall and what is its main function?
Correct Answer
A. A specialized epithelial cell responsible for antigen transcytosis
Explanation
The M cell is a specialized epithelial cell found in the intestinal wall. Its main function is to facilitate antigen transcytosis, which is the process of transporting antigens from the lumen of the intestines to the underlying immune cells in the gut-associated lymphoid tissue. This allows for the initiation of an immune response against potential pathogens or harmful substances that enter the intestinal tract. M cells play a crucial role in the immune surveillance and defense mechanism of the intestinal mucosa.
21.
System-based practice
Measurement of healthcare systems occurs on many levels. Measurement may be used for research, for judgment, and for improvement of care. Here is a table comparing outcomes of care at a state level with a composite score, acute myocardial infarction (AMI), chronic heart failure (CHF) and pneumonia.
Table. Technical Process Quality Measure Scores (0-100; low—hi)
State
Composite
AMI
CHF
Pneumonia
California
86
93
94
72
Connecticut
80
90
84
61
Massachusetts
93
96
95
87
This is an example of what type of measurement?
Correct Answer
B. Judgment
Explanation
State and country comparison, especially data that are aggregated, are generally used for judgment about whether care is good or not. Data for improvement focuses on data that examine and understand the variation in data over time (run chart or control chart). These are not research data.
22.
You are working with a team in mental health to improve the access time for new patients in psychiatry clinic. Over the past several months, the clinic has seen an increase in the number of patients, but this has led to long wait times for some patients to get seen in the clinic. The clinic has set a goal of referral to appointment date of 21 days. You examine the number of days from a patient's referral until he or she is seen in the clinic and chart the past 30 patient referrals on the following run chart.
You notice a trend with 8 increasing data points from patient 18 through patient 25. What is the appropriate next step for the team?
Correct Answer
E. Investigate the special cause signal to find why the time from referral to appointment
increased.
Explanation
This question examines the student's ability to take the correct action based on the information from the chart. The student does not need to interpret the chart, but only determine the correct action.
Answer a. is not correct because there is a clear need for action.
Answer b. does not interpret the data correctly. Quality managers might be able to help make this better, but this is not the right next step.
This problem is definitely part of what a physician needs to address, so d. is not correct