3. (Aeronautics) any structure corresponding to or resembling the keel of a ship, such as the central member along the bottom of an aircraft fuselage. 4. (Biology) biology a ridgelike part; carina. 5. a poetic word for ship.
Transverse colon and sigmoid colon. The transverse colon and the sigmoid colon have a mesentery (ie, transverse mesocolon and sigmoid mesocolon, respectively), but the ascending colon and descending colon are retroperitoneal, while the cecum is intraperitoneal but uses the mesentery of the ileum.
The left half of the transverse colon continues from the right upper quadrant to the left upper quadrant. It bends at the splenic flexure to become the descending colon and runs downwards to the left lower quadrant. Here it continues as the sigmoid colon and connects with the rectum.