A ________ is a central, open area inside a tubular structure, such as the esophagus, small intestine, and large intestine.
A. haustra
B. lumen
C. sphincter
D. fundus
Answer:B
A ________ is a central, open area inside a tubular structure, such as the esophagus, small intestine, and large intestine.
A. haustra B. lumen C. sphincter D. fundus
Explanation: A) Haustra are pouches in the large intestine.