How many pairs of muscles are there in the abdominal wall?

• A. 6
• B. 2
• C. 4
• D. 5

Answer: (C)

The abdominal wall is built from paired muscles on both sides, organized in layers plus a central vertical muscle. On each side there are three flat muscles that form the lateral walls: the external oblique, the internal oblique, and the transversus abdominis. In addition, there is the rectus abdominis along the front of the abdomen, present as one muscle on each side of the midline, making a second paired group. Counting all the paired muscles gives four pairs in total. If you only consider the lateral layers, you’d count fewer pairs; if you tried to count more, you’d be double-counting or miscounting the midline structure. Four pairs is the standard tally.