Which combining form is used to describe a diverticulum or pouch in a tubular organ?

• A. Epitheli/o
• B. Arc/o
• C. Tympan/o
• D. Diverticul/o

Answer: (D)

Diverticul/o is the combining form used to describe a diverticulum, an outpouching of a hollow, tubular organ such as the intestine. This form attaches to suffixes to form terms like diverticulitis (inflammation of a diverticulum) or diverticulosis (presence of diverticula). The other forms refer to unrelated structures: epitheli/o = epithelium; arc/o = arch or bow-related sense; tympan/o = the eardrum or tympanic region. So diverticul/o is the correct form for a pouch in a tubular organ.