Digestive System — MCQs
Stenson's duct of parotid gland opens opposite to:
CT scan of abdomen showing a structure branching within the liver. Identify the structure.
Which of the following is the most complete statement about the appendix?
A patient presents with abdominal distension. Based on the X-ray, which of the following bowel loops are dilated?
What is the diagnosis based on the image shown?
All of the following statements about Zenker's diverticulum are true except.
Which of the following statements about the first part of the duodenum is false?
Ducts of Bellini are present in:
Prefilaggrin is found in which layer of epidermis?
Which of the following does not form a visceral relation with the spleen?
Digestive System Indian Medical PG Practice Questions and MCQs
Question 1: Stenson's duct of parotid gland opens opposite to:
- A. Lower second premolar
- B. Lower second molar
- C. Upper second molar (Correct Answer)
- D. Upper second premolar
Explanation: ***Upper second molar*** - Stenson's duct, also known as the **parotid duct**, pierces the **buccinator muscle** and opens into the oral vestibule. - Its **opening is located** opposite the crown of the **upper second molar tooth**. *Lower second premolar* - This tooth is located in the **mandibular arch**, whereas the parotid duct opens in the **maxillary region**. - The opening of Stenson's duct is generally found higher up in the oral cavity. *Lower second molar* - Similar to the premolar, this tooth is in the **lower jaw**, making it an incorrect location for the Stenson's duct opening. - The duct specifically opens in relation to the **upper dentition**. *Upper second premolar* - While located in the upper jaw, the Stenson's duct opening is typically more posterior, opposite the **second molar**, not the second premolar. - The opening is consistently associated with the **molar region**.
Question 2: CT scan of abdomen showing a structure branching within the liver. Identify the structure.
- A. Portal vein (Correct Answer)
- B. Superior vena cava
- C. Inferior vena cava
- D. Splenic vein
Explanation: ***Portal vein*** - The image shows a **branching vessel within the liver parenchyma**. The **portal vein** enters the liver at the porta hepatis and branches extensively to supply the liver with nutrient-rich, deoxygenated blood from the gastrointestinal tract. - On a CT scan, the portal vein and its branches appear as prominent, contrast-filled structures centrally located within the liver, consistent with the identified structure. *Superior Vena Cava* - The **superior vena cava** is located in the **chest**, superior to the diaphragm, and drains blood from the upper body into the right atrium; it does not branch within the liver. - This vessel would not be visible in an abdominal CT slice at this level and does not show intrahepatic branching. *Inferior Vena Cava* - The **inferior vena cava (IVC)** is a large vessel located **posterior to the liver**, collecting deoxygenated blood from the lower body and liver (via hepatic veins) before emptying into the right atrium. - While it is in the abdomen, it does not branch within the liver parenchyma in the same manner as the portal vein; rather, **hepatic veins** drain into it from the liver. *Splenic Vein* - The **splenic vein** runs along the **posterior aspect of the pancreas** and eventually joins with the superior mesenteric vein to form the portal vein outside the liver. - It does not enter or branch within the liver itself; its location is too far posterior and outside the liver to match the structure indicated.
Question 3: Which of the following is the most complete statement about the appendix?
- A. It does not have mesentery.
- B. It has taenia coli.
- C. It develops from the midgut and is supplied by the appendicular branch of the ileocolic artery. (Correct Answer)
- D. It develops from the midgut.
Explanation: ***It develops from the midgut and is supplied by the appendicular branch of the ileocolic artery.*** - The appendix originates embryologically from the **midgut**, which also gives rise to the distal duodenum to the proximal two-thirds of the transverse colon [1]. - Its blood supply is derived from the **appendicular artery**, a branch of the **ileocolic artery**, which itself originates from the superior mesenteric artery (a major midgut vessel) [2]. - This option provides the most comprehensive information, combining both embryological origin and vascular supply. *It does not have mesentery.* - The appendix is attached to the mesentery of the ileum by a small mesentery of its own, called the **mesoappendix**, which contains the appendicular artery. - This statement is **incorrect** as the presence of a mesoappendix clearly indicates it does possess a mesentery. *It has taenia coli.* - The taenia coli are three distinct longitudinal bands of smooth muscle found on the outer surface of the **cecum** and **colon**. - The three taenia coli **converge at the base of the appendix** to form its outer longitudinal muscle layer, but the appendix itself does not have taenia coli running along its length. - This statement is **incorrect**. *It develops from the midgut.* - While this statement is factually **true**, it is incomplete compared to the correct answer. - The appendix does develop from the midgut, but this option lacks additional distinguishing information about its vascular supply, making it less complete than the best answer.
Question 4: A patient presents with abdominal distension. Based on the X-ray, which of the following bowel loops are dilated?
- A. Jejunum (Correct Answer)
- B. Duodenum
- C. Transverse colon
- D. Ileum
Explanation: ***Jejunum*** - The image shows dilated small bowel loops with prominent **valvulae conniventes** (also known as plicae circulares), which are characteristic of the jejunum. - These folds are typically closely spaced and extend across the entire lumen, giving a "coiled spring" or "stack of coins" appearance on plain radiographs when dilated. *Duodenum* - While the duodenum is part of the small bowel, it is the most proximal segment and typically not as diffusely involved in generalized small bowel dilation as the jejunum and ileum unless the obstruction is very high. - The valvulae conniventes in the duodenum are less prominent and more sparsely distributed compared to the jejunum. *Transverse colon* - The transverse colon is part of the large intestine and would show **haustra**, which are sacculations that do not extend across the entire lumen and are typically more widely spaced than valvulae conniventes. - The dilated loops in the image clearly show mucosal folds that span the entire width of the bowel. *Ileum* - The ileum also has valvulae conniventes, but they are less prominent and more sparsely distributed than in the jejunum. - In cases of small bowel obstruction or dilation, the jejunum characteristically shows more distinct and closely packed valvulae conniventes, making it the most identifiable segment in this image.
Question 5: What is the diagnosis based on the image shown?
- A. Ileal diverticulum
- B. Urachal cyst
- C. Umbilical fistula (Correct Answer)
- D. Omphalocele
Explanation: ***Umbilical fistula*** - The image shows a **patent vitelline duct (omphalomesenteric duct)**, which creates a direct connection between the umbilicus and the ileum, visible as an umbilical fistula. - This condition presents with **fecal discharge from the umbilicus** or **umbilical prolapse of intestinal mucosa**. *Ileal diverticulum* - An ileal diverticulum, such as a **Meckel's diverticulum**, is a blind pouch protruding from the ileum, usually not communicating with the umbilicus. - It would typically be noted as an **outpouching of the ileal wall**, without an external opening at the umbilicus unless complicated by rupture. *Urachal cyst* - A urachal cyst is a remnant of the **urachus**, which connects the bladder to the umbilicus during fetal development. - It would be located **between the umbilicus and the bladder** and contain urine or serous fluid, not intestinal contents. *Omphalocele* - An omphalocele is a **congenital abdominal wall defect** where abdominal organs protrude into the base of the umbilical cord. - The defect is **covered by a membrane**, and it involves herniation of abdominal contents, not a fistula with the intestine.
Question 6: All of the following statements about Zenker's diverticulum are true except.
- A. It is a true diverticulum. (Correct Answer)
- B. Acquired diverticulum
- C. Lateral X-rays on Barium swallow are often diagnostic.
- D. Outpouching of the posterior pharyngeal wall, just above the cricopharyngeus muscle.
Explanation: ***It is a true diverticulum.*** - A Zenker's diverticulum is a **false diverticulum**, meaning it involves an outpouching of only the **mucosa and submucosa** through a defect in the muscular layer, not all layers of the esophageal wall. - **True diverticula** contain all layers of the esophageal wall (mucosa, submucosa, and muscularis propria), whereas a Zenker's diverticulum lacks the muscular layer in its wall. *Acquired diverticulum* - Zenker's diverticulum is an **acquired condition**, typically developing later in life due to increased pressure and discoordination of the pharyngeal muscles. - It results from a herniation of the pharyngeal mucosa through a weak point, the **Killian's triangle**, due to prolonged high intraluminal pressure. *Lateral X-rays on Barium swallow are often diagnostic.* - A **barium swallow** is the diagnostic procedure of choice, clearly visualizing the posterior outpouching of the pharyngeal wall. - **Lateral views** are particularly effective in demonstrating the location and size of the diverticulum, distinguishing it from other esophageal abnormalities. *Outpouching of the posterior pharyngeal wall, just above the cricopharyngeus muscle.* - Zenker's diverticulum is specifically located in the **Killian's triangle**, a weak area in the posterior wall of the pharynx superior to the **cricopharyngeus muscle**. - This anatomical position explains why it causes symptoms such as **dysphagia**, regurgitation of undigested food, and halitosis due to food accumulation.
Question 7: Which of the following statements about the first part of the duodenum is false?
- A. 5 cm long
- B. Is superior part
- C. Develops from foregut
- D. Supplied by the superior mesenteric artery (Correct Answer)
Explanation: ***Supplied by the superior mesenteric artery*** - The first part of the duodenum, derived from the **foregut**, receives its blood supply from the **gastroduodenal artery**, a branch of the celiac artery [1], [2]. - The **superior mesenteric artery** primarily supplies the **midgut** derivatives, which include the distal half of the duodenum and onward [2]. *5 cm long* - The first part of the duodenum is indeed the **shortest** and widest section, typically measuring about **5 cm (2 inches)** in length. - This length allows it to course from the pylorus to the inferior border of the L1 vertebra. *Is superior part* - This statement is correct as the first part courses **superiorly** and then posteriorly, crossing the right crus of the diaphragm. - It lies at the level of the **L1 vertebra**. *Develops from foregut* - The first part of the duodenum, along with the other upper gastrointestinal structures (stomach, liver, pancreas), indeed develops from the **embryonic foregut** [1]. - The transition from foregut to midgut occurs at the level of the **major duodenal papilla**.
Question 8: Ducts of Bellini are present in:
- A. Pancreas
- B. Liver
- C. Kidney (Correct Answer)
- D. Salivary gland
Explanation: ***Kidney*** - The Ducts of Bellini, also known as **large papillary collecting ducts**, are the terminal portions of the collecting duct system in the kidney. - They are located in the **renal medulla**, particularly within the renal papillae, and drain urine into the minor calyces. *Pancreas* - The pancreas is involved in **digestion** and hormone production (e.g., insulin), not urine formation. - Its duct system includes the **main pancreatic duct (Wirsung's duct)** and accessory pancreatic duct. *Liver* - The liver's primary functions are **metabolism**, detoxification, and bile production. Its duct system consists of **bile ducts**, which transport bile, not urine [1], [2]. - Its duct system consists of **bile ducts**, which transport bile, not urine. *Salivary gland* - Salivary glands produce **saliva** and have their own unique duct systems (e.g., Wharton's duct, Stensen's duct). - These glands are part of the digestive system and are not involved in renal function.
Question 9: Prefilaggrin is found in which layer of epidermis?
- A. Stratum granulosum (Correct Answer)
- B. Stratum basale
- C. Stratum spinosum
- D. Stratum corneum
Explanation: ***Stratum granulosum*** - **Prefilaggrin** is synthesized in the **stratum granulosum** as a large, insoluble protein that is stored in keratohyalin granules [1]. - It later undergoes proteolytic cleavage to form **filaggrin**, which is crucial for keratin filament aggregation and skin barrier function in the upper layers [1]. *Stratum basale* - This layer contains **basal cells** responsible for epidermal regeneration and is where keratinocyte proliferation occurs [1]. - It does not contain prefilaggrin, as this protein is synthesized in more differentiated keratinocytes. *Stratum spinosum* - This layer is characterized by abundant **desmosomes** (spinous processes) providing structural integrity. - While keratinization begins here, **prefilaggrin synthesis** primarily occurs in the stratum granulosum. *Stratum corneum* - This outermost layer consists of flattened, dead keratinocytes filled with **keratin** and **filaggrin**, a breakdown product of prefilaggrin [1]. - **Prefilaggrin itself is not found here**; it has already been processed into filaggrin by the time cells reach this layer.
Question 10: Which of the following does not form a visceral relation with the spleen?
- A. Stomach
- B. Splenic flexure of colon
- C. Left kidney
- D. Adrenal glands (Correct Answer)
Explanation: The adrenal glands, specifically the **left adrenal gland**, are located superior to the **left kidney** but are generally not in direct visceral relation with the spleen itself [2]. The spleen's concavities accommodate other organs. The spleen is typically located in the **left hypochondrium**, nestled against the diaphragm, superior to the left kidney, but the adrenal gland is usually separated by the kidney or surrounding fascia. *Stomach* - The **gastric impression** on the spleen's anterior surface is formed by the fundus of the **stomach**, indicating a direct visceral relation [3]. - The stomach is one of the primary organs that directly abuts the spleen's visceral surface. *Splenic flexure of colon* - The **colic impression** on the inferior aspect of the spleen is formed by the **splenic flexure of the colon**, confirming a direct visceral relation [1]. - This anatomical arrangement explains why an enlarged spleen can sometimes be palpated near the colon. *Left kidney* - The **renal impression** on the posterior aspect of the spleen is formed by the anterior superior surface of the **left kidney**, establishing a clear visceral relation [1]. - The spleen lies directly superior and lateral to the left kidney.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free