**Question:** A 62-year-old man develops abdominal pain after eating. An arteriogram reveals absence of blood flow in the celiac artery. Collateral branches supply the stomach through which of the following?

A. Mesenteric artery
B. Superior mesenteric artery
C. Aorta
D. Hepatic artery

**Core Concept:**
In humans, the celiac artery is a branch of the abdominal aorta and supplies blood to the stomach, spleen, and part of the small intestine. When there is absence of blood flow in the celiac artery, collateral vessels are activated to provide alternate blood supply to these organs.

**Why the Correct Answer is Right:**
In this scenario, the correct answer is **B. Superior mesenteric artery** because it serves as a major collateral pathway when the celiac artery is obstructed. The superior mesenteric artery originates from the abdominal aorta and supplies blood to the small intestine, part of the stomach, and the spleen. When the celiac artery is obstructed, the superior mesenteric artery takes over the function of supplying blood to the stomach and part of the small intestine.

**Why Each Wrong Option is Incorrect:**

A. **Mesenteric artery** is incorrect because it is a branch of the celiac artery and doesn't serve as a collateral pathway when the celiac artery is obstructed.

B. **Hepatic artery** is incorrect because it supplies blood to the liver and bile ducts, not the stomach.

C. **Aorta** is incorrect because the aorta is the main trunk supplying blood to the abdomen but does not directly supply the stomach or small intestine.

**Clinical Pearl:**
In clinical practice, understanding collateral pathways is essential for physicians as it enables them to diagnose and manage cases involving vascular occlusions or stenosis. This concept helps in formulating a proper treatment plan and predicting the affected organs in case of occlusion of the celiac artery or its branches.