Abdomen Practice Questions

Q: Gallstone pain is referred to the shoulder. Which nerve roots are involved in this referred pain?

C3-C5. ### Explanation **1. Why C3-C5 is Correct:** The gallbladder is located inferior to the diaphragm. If a gallstone causes inflammation (cholecystitis), the gallbladder may irritate the **parietal peritoneum** of the diaphragm [2]. The central part of the diaphragm is innervated by the **Phrenic Nerve**, which originates from the spinal cord segments **C3, C4, and C5** ("C3, 4, 5 keep the diaphragm alive"). This is an example of **referred pain**: the sensory fibers of the phrenic nerve enter the spinal cord at the same level as the **supraclavicular nerves** (C3-C4), which supply the skin over the shoulder [1]. The brain misinterprets the visceral irritation from the diaphragm as coming from the skin of the right shoulder (specifically the tip of the acromion). **2. Why the Other Options are Incorrect:** * **C2-C8:** This range is too broad. While it includes the phrenic roots, C2 is primarily involved in the scalp/neck, and C6-C8 supply the upper limb (brachial plexus). * **T8-T9:** These are the sympathetic segments for the gallbladder [3]. Irritation here causes the initial "dull" visceral pain felt in the **epigastrium**, not the shoulder. * **T4-T6:** These segments correspond to the dermatomes of the upper thorax/nipple line. Pain here is more characteristic of cardiac or esophageal issues. **3. Clinical Pearls for NEET-PG:** * **Boas’ Sign:** Hyperesthesia (increased sensitivity) below the right scapula (T7-T9) due to phrenic nerve irritation. * **Murphy’s Sign:** Inspiratory arrest upon deep palpation of the right hypochondrium; a hallmark of acute cholecystitis. * **Kehr’s Sign:** Similar referred pain to the **left** shoulder, typically indicating a ruptured spleen (blood irritating the left diaphragm).

Q: Hyperextension of the hip producing pain in acute appendicitis is due to irritation of which muscle?

Psoas major. The correct answer is **C. Psoas major**. This clinical phenomenon is known as the **Psoas Sign**. In cases of acute appendicitis, particularly when the appendix is in a **retrocecal position**, it lies directly over the psoas major muscle [1]. Inflammation of the appendix causes irritation of the underlying psoas fascia. When the hip is hyperextended, the psoas muscle is stretched; this movement rubs the inflamed muscle against the appendix, eliciting sharp abdominal pain [2]. **Analysis of Incorrect Options:** * **A. Gluteus maximus:** This is the primary extensor of the hip, but it is located posteriorly in the gluteal region and does not come into contact with the appendix. * **B. Obturator externus:** Irritation of the *Obturator internus* (not externus) occurs in the **Obturator Sign**, typically seen in pelvic appendicitis [2]. This is elicited by internal rotation of the flexed thigh. * **C. Quadratus lumborum:** This muscle forms the posterior abdominal wall but is located deeper and more superior/lateral than the psoas, making it an unlikely source of pain during hip extension in appendicitis. **High-Yield Clinical Pearls for NEET-PG:** * **Retrocecal Appendix:** The most common position (approx. 65%). It is associated with a positive Psoas Sign [1]. * **Pelvic Appendix:** The second most common position (approx. 30%). It is associated with a positive **Obturator Sign** [2]. * **McBurney’s Point:** Located 1/3rd of the distance from the Right Anterior Superior Iliac Spine (ASIS) to the Umbilicus; it corresponds to the base of the appendix. * **Rovsing’s Sign:** Pain in the Right Iliac Fossa (RIF) triggered by palpation of the Left Iliac Fossa (LIF) [2].

Q: Which of the following is a direct branch of the abdominal aorta?

Testicular artery. The abdominal aorta gives off three types of branches: visceral (paired and unpaired), parietal, and terminal. Understanding the origin of these vessels is a high-yield topic for NEET-PG. ### **Why the Correct Answer is Right** **D. Testicular artery:** This is a **paired visceral branch** of the abdominal aorta. It typically arises from the anterior aspect of the aorta just below the origin of the renal arteries (at the level of **L2**). In females, the equivalent branch is the ovarian artery. Both are collectively known as the gonadal arteries. ### **Why the Other Options are Incorrect** * **A. Superior suprarenal artery:** This is a branch of the **inferior phrenic artery** (which itself is a branch of the aorta). The middle suprarenal artery is a direct branch of the aorta, while the inferior suprarenal arises from the renal artery. * **B & C. External and Internal iliac arteries:** These are the terminal divisions of the **common iliac artery**. The abdominal aorta ends at the level of **L4** by bifurcating into the right and left common iliac arteries [1]; it does not give off the external or internal iliacs directly. ### **High-Yield Clinical Pearls for NEET-PG** 1. **Levels of Origin:** Celiac trunk (T12), Superior Mesenteric (L1), Renal (L2), Inferior Mesenteric (L3), Bifurcation (L4) [1]. 2. **Nutcracker Syndrome:** The left testicular (or ovarian) vein drains into the left renal artery, which can be compressed between the SMA and the aorta, leading to a varicocele. 3. **Unpaired Visceral Branches:** Celiac trunk, SMA, and IMA. 4. **Paired Visceral Branches:** Middle suprarenal, Renal, and Gonadal arteries.

Q: The transverse mesocolon contains which of the following arteries?

Middle colic artery. Explanation: The **transverse mesocolon** is a broad, fan-shaped fold of peritoneum that connects the transverse colon to the posterior abdominal wall [1]. It serves as a conduit for neurovascular structures supplying the midgut-derived portion of the large intestine. **Why the Middle Colic Artery is Correct:** The **middle colic artery**, a branch of the Superior Mesenteric Artery (SMA), enters the layers of the transverse mesocolon [1]. It divides into right and left branches to supply the transverse colon [1]. It also participates in the formation of the **Marginal Artery of Drummond**, providing critical collateral circulation [1]. **Analysis of Incorrect Options:** * **Left Colic Artery (Option A):** A branch of the Inferior Mesenteric Artery (IMA), it supplies the descending colon and is located retroperitoneally or within the sigmoid mesocolon (distally) [1]. * **Right Colic Artery (Option B):** A branch of the SMA that supplies the ascending colon. Since the ascending colon is a retroperitoneal organ, this artery does not travel within a mesentery. * **Ileocolic Artery (Option D):** The terminal branch of the SMA supplying the cecum, appendix, and terminal ileum. It travels retroperitoneally toward the right iliac fossa. **High-Yield Clinical Pearls for NEET-PG:** * **Root of Transverse Mesocolon:** It crosses the anterior surface of the head and body of the pancreas. This is a common site for the spread of pancreatic inflammatory fluid (pseudocysts) or malignancy into the transverse colon. * **Surgical Landmark:** The transverse mesocolon divides the abdominal cavity into **supracolic** (stomach, liver, spleen) and **infracolic** (small intestine, ascending/descending colon) compartments. * **Arc of Riolan:** This is a direct communication between the SMA (middle colic) and IMA (left colic) found within the mesocolon, vital during mesenteric ischemia [1].

Q: A 32-year-old man presents with a painless mass in his right scrotum of several months' duration. Ultrasonography shows a homogeneous hypoechoic intratesticular mass. Biopsy reveals a seminoma. To which of the following lymph nodes does cancer of the testis first metastasize?

Lumbar. ### Explanation **1. Why the Correct Answer is Right:** The lymphatic drainage of an organ follows its **embryological origin** and its **arterial supply**. The testes develop in the high posterior abdominal wall (at the level of L2) and descend into the scrotum during fetal development, carrying their neurovascular and lymphatic supply with them. The testicular arteries arise directly from the abdominal aorta. Consequently, lymph from the testis drains via the lymphatic vessels in the spermatic cord to the **Lumbar (Para-aortic) lymph nodes**, located at the level of the L1-L2 vertebrae [1]. **2. Why the Other Options are Wrong:** * **Deep Inguinal (A):** These nodes receive drainage from the glans penis and the distal spongy urethra. They do not receive primary drainage from the testis. * **External Iliac (B):** These nodes primarily drain the pelvic viscera (e.g., superior bladder, cervix) and the deep lymphatics of the lower limb. * **Internal Iliac (C):** These nodes drain most of the pelvic organs, including the prostate, seminal vesicles, and the upper part of the vagina/rectum. **3. High-Yield Clinical Pearls for NEET-PG:** * **Scrotum vs. Testis:** This is a classic "trap" question. While the **testis** drains to the **Lumbar (Para-aortic) nodes**, the **scrotum** (skin) drains to the **Superficial Inguinal nodes** [1]. * **Metastasis Pattern:** In testicular cancer, a radical orchidectomy is performed via an inguinal approach (not trans-scrotal) to avoid seeding the cancer into the superficial inguinal nodes. * **Right vs. Left:** Lymph from the right testis drains specifically to the **precaval and aortocaval** nodes, while the left testis drains to the **pre-aortic and para-aortic** nodes. * **Exception:** If a tumor invades the tunica vaginalis or the scrotal skin, it may then spread to the inguinal lymph nodes [1].

Q: Ligation of the coeliac artery mostly affects all of the following organs except:

Jejunum. ### Explanation The **coeliac artery (trunk)** is the artery of the **foregut**. It supplies all derivatives of the embryonic foregut, which extends from the lower esophagus to the second part of the duodenum (at the level of the opening of the common bile duct) [1]. **1. Why Jejunum is the correct answer:** The **jejunum** is a derivative of the **midgut**. The arterial supply to the midgut (extending from the distal half of the second part of the duodenum to the junction of the proximal two-thirds and distal one-third of the transverse colon) is provided by the **Superior Mesenteric Artery (SMA)** [1]. Therefore, ligation of the coeliac trunk does not directly affect the blood supply to the jejunum. **2. Why the other options are incorrect:** * **Stomach (A):** The stomach is a foregut organ supplied by all three branches of the coeliac trunk (Left gastric, Splenic, and Common hepatic arteries). * **Pancreas (B):** The head of the pancreas receives blood from both the coeliac trunk (via the superior pancreaticoduodenal artery) and the SMA [1]. However, the body and tail are supplied exclusively by the splenic artery, a branch of the coeliac trunk. * **Spleen (D):** The spleen is supplied by the splenic artery, the largest branch of the coeliac trunk. **Clinical Pearls for NEET-PG:** * **Coeliac Trunk Level:** Originates from the abdominal aorta at the level of the **T12/L1** disc. * **Three Main Branches:** Left gastric artery (smallest), Splenic artery (largest/tortuous), and Common hepatic artery. * **Watershed Area:** The **duodenum** acts as the transition zone where the blood supply shifts from the coeliac trunk to the SMA via the pancreaticoduodenal anastomoses [1]. * **Clinical Significance:** Sudden occlusion of the coeliac trunk is often compensated by collateral circulation from the SMA, but acute ligation during surgery will primarily ischemia-stress the stomach, liver, and spleen.

Q: A patient was admitted with symptoms of bowel obstruction. Further examination revealed that the obstruction was caused by the nutcracker-like compression of the bowel between the superior mesenteric artery and the aorta. The compressed bowel is MOST likely to be:

Duodenum. ### Explanation The clinical scenario describes **Superior Mesenteric Artery (SMA) Syndrome**, also known as Wilkie’s syndrome. **1. Why the Duodenum is correct:** The **third (horizontal) part of the duodenum** passes transversely between the abdominal aorta (posteriorly) and the superior mesenteric artery (anteriorly) [1]. Normally, a fat pad maintains an angle of approximately 45° between these two vessels. If this angle narrows (usually <25° due to rapid weight loss or loss of mesenteric fat), the duodenum is compressed like a "nutcracker," leading to proximal bowel obstruction [1]. **2. Why the incorrect options are wrong:** * **Jejunum and Ileum:** These parts of the small intestine are located distal to the SMA's origin and are suspended by the mesentery. They do not pass through the narrow vascular space between the aorta and the SMA. * **Ascending Colon:** This is a retroperitoneal structure located in the right paracolic gutter, far lateral to the midline where the SMA and aorta intersect. **3. Clinical Pearls for NEET-PG:** * **Nutcracker Syndrome vs. SMA Syndrome:** While SMA syndrome involves compression of the **duodenum**, "Nutcracker Syndrome" specifically refers to the compression of the **left renal vein** between the SMA and the aorta, leading to hematuria and left-sided varicocele. * **Predisposing Factors:** Rapid weight loss (e.g., malignancy, eating disorders), spinal surgery (correcting scoliosis), or prolonged bed rest in a body cast [1]. * **Relieving Factor:** Symptoms are often relieved by the **left lateral decubitus** or knee-chest position, which increases the SMA-aorta angle. * **Anatomical Landmark:** The SMA arises from the aorta at the level of **L1**.

Question 1

A 55-year-old man was 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?

Accepted Answer

Omental bursa (lesser sac)

Answer

Right subhepatic space

Answer

Hepatorenal space (of Morison)

Answer

Right subphrenic space

Question 2

Gallstone pain is referred to the shoulder. Which nerve roots are involved in this referred pain?

Accepted Answer

C3-C5

Answer

C2-C8

Answer

T8-T9

Answer

T4-T6

Question 3

Hyperextension of the hip producing pain in acute appendicitis is due to irritation of which muscle?

Accepted Answer

Psoas major

Answer

Gluteus maximus

Answer

Obturator externus

Answer

Quadratus lumborum

Question 4

Which of the following is a direct branch of the abdominal aorta?

Accepted Answer

Testicular artery

Answer

Superior suprarenal artery

Answer

External iliac artery

Answer

Internal iliac artery

Question 5

The transverse mesocolon contains which of the following arteries?

Accepted Answer

Middle colic artery

Answer

Left colic artery

Answer

Right colic artery

Answer

Ileocolic artery

Question 6

All of the following statements regarding the adrenal gland are true except?

Accepted Answer

Both adrenal glands drain directly into the inferior vena cava.

Answer

Both adrenal glands are supplied by three arteries.

Answer

The right adrenal gland is pyramidal in shape.

Answer

The average weight of an adrenal gland is about 5 grams.

Question 7

A 32-year-old man presents with a painless mass in his right scrotum of several months' duration. Ultrasonography shows a homogeneous hypoechoic intratesticular mass. Biopsy reveals a seminoma. To which of the following lymph nodes does cancer of the testis first metastasize?

Accepted Answer

Lumbar

Answer

Deep inguinal

Answer

External iliac

Answer

Internal iliac

Question 8

Ligation of the coeliac artery mostly affects all of the following organs except:

Accepted Answer

Jejunum

Answer

Stomach

Answer

Pancreas

Answer

Spleen

Question 9

What is true about splenunculi?

Accepted Answer

It is encapsulated

Answer

The most common site is the tail of the pancreas

Answer

It is often single

Answer

It has more red pulp than the spleen

Question 10

A patient was admitted with symptoms of bowel obstruction. Further examination revealed that the obstruction was caused by the nutcracker-like compression of the bowel between the superior mesenteric artery and the aorta. The compressed bowel is MOST likely to be:

Accepted Answer

Duodenum

Answer

Jejunum

Answer

Ileum

Answer

Ascending colon

Abdomen — MCQs

Abdomen — MCQs

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