Derivatives of midgut ?
**Core Concept**
The midgut is one of the three main divisions of the embryonic gut, which gives rise to a significant portion of the small intestine and a part of the large intestine. Derivatives of the midgut include the distal one-third of the duodenum, the entire jejunum, the entire ileum, the cecum, the ascending colon, and the right two-thirds of the transverse colon.
**Why the Correct Answer is Right**
The midgut develops from the midgut loop, which undergoes a process called intestinal rotation and fixation during embryonic development. This process involves the midgut loop rotating 270 degrees and eventually returning to the abdominal cavity, where it forms the distal one-third of the duodenum, the jejunum, and the ileum. The derivatives of the midgut also include the cecum, which forms from the hindgut but is connected to the midgut derivatives. The ascending colon and the right two-thirds of the transverse colon develop from the midgut.
**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect because the foregut derivatives include the proximal one-third of the duodenum, the entire pancreas, and the liver.
**Option B:** This is incorrect because the hindgut derivatives include the distal one-third of the transvers colon, the descending colon, the sigmoid colon, and the rectum.
**Option C:** This is incorrect because the omphalomesenteric duct, also known as the vitelline duct, is a remnant of the connection between the midgut and the yolk sac, but it is not a derivative of the midgut.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the midgut derivatives are prone to malrotation, a condition where the midgut loop fails to return to the abdominal cavity and undergoes abnormal rotation, leading to intestinal obstruction.
**Correct Answer: D. The entire cecum, the ascending colon, and the right two-thirds of the transverse colon.