Derivative of dorsal mesogastrium ?
**Core Concept**
The development of the gastrointestinal tract, particularly the derivatives of the dorsal and ventral mesogastrium, is crucial in understanding the embryological origin of abdominal organs. The dorsal mesogastrium gives rise to structures that are closely associated with the stomach.
**Why the Correct Answer is Right**
The correct answer is related to the development of the spleen. The dorsal mesogastrium is a fold of tissue that connects the stomach to the body wall during embryonic development. As the stomach rotates, the dorsal mesogastrium develops into the greater omentum and the splenorenal ligament, which contain the spleen. The splenic artery, which supplies blood to the spleen, also arises from the celiac trunk, a branch of the abdominal aorta. The development of the spleen from the dorsal mesogastrium is a critical step in the formation of the lymphoid organs in the abdominal cavity.
**Why Each Wrong Option is Incorrect**
**Option A:** The greater omentum is indeed a derivative of the dorsal mesogastrium, but it is not the primary structure derived from this tissue fold. The greater omentum is a large fold of peritoneum that hangs from the greater curvature of the stomach and the proximal part of the duodenum.
**Option B:** The lesser omentum is actually a derivative of the ventral mesogastrium, not the dorsal mesogastrium. It connects the liver to the lesser curvature of the stomach and the proximal part of the duodenum.
**Option C:** The pancreas is derived from both the dorsal and ventral pancreatic buds, which arise from the foregut endoderm. While the dorsal pancreatic bud is closely associated with the splenic artery and the dorsal mesogastrium, it is not a direct derivative of this tissue fold.
**Option D:** The liver is derived from the endoderm of the foregut, specifically from the hepatic diverticulum. It is not a derivative of the dorsal mesogastrium.
**Clinical Pearl / High-Yield Fact**
The splenic artery is a branch of the celiac trunk, which arises from the abdominal aorta. It is responsible for supplying blood to the spleen, and its occlusion can lead to splenic infarction. The splenic vein, on the other hand, drains blood from the spleen into the portal vein.
**Correct Answer: B. The lesser omentum is actually a derivative of the ventral mesogastrium, not the dorsal mesogastrium. It connects the liver to the lesser curvature of the stomach and the proximal part of the duodenum.**