Anatomy of the caecum, appendix, and colon.

The large intestine comprises the caecum and appendix, colon, rectum, and anal canal from proximal to distal. Embryologically, the proximal half of the large intestine is derived from the midgut, while the distal half develops from the hindgut. This dual derivation is reflected in the difference in arterial supply to its proximal (superior mesenteric artery) and distal (inferior mesenteric artery) portions. Physiologically, the large intestine primarily functions to absorb water and essential electrolytes (sodium and chloride) from its luminal contents leaving the unabsorbed residue to be excreted as faeces. Fibre-optic colonoscopy and MRI and CT colonography allow detailed internal inspection of the large intestine with relative ease and with minimal discomfort. This article highlights the clinically and surgically relevant aspects of the anatomy of the caecum, appendix, and colon. [ABSTRACT FROM AUTHOR]