Which set comprises the distinguishing features of the large intestine?

• A. Taenia coli, Haustra, Epiploic appendages
• B. Haustra, Epiploic appendages, Microvilli
• C. Haustra, Epiploic appendages, Gastric rugae
• D. Taenia coli, Haustra, Plicae circulares

Answer: (A)

The large intestine has a distinctive wall pattern marked by three features that set it apart. Taenia coli are three thick bands of longitudinal smooth muscle that run along the length of the colon. These bands create the segmented appearance known as haustra, which are sacculations in the wall that form as the taenia coli contract. Hanging along the colon are epiploic appendages, small peritoneal fat-filled pouches. Together, taenia coli, haustra, and epiploic appendages give the colon its signature structure and appearance.

Other options mix features that aren’t unique to the large intestine. Microvilli are brush-border structures seen in absorptive cells throughout the small and large intestines, not a distinguishing feature of the colon. Gastric rugae are folds of the stomach mucosa, and plicae circulares are circular folds in the small intestine. These are not characteristic of the large intestine.