Answer:
circular folds
Step-by-step explanation:
The movement of food in the body's alimentary canal (the passage of food from the mouth towards the anus) is aided by "peristalsis."
"Peristalsis" is an involuntary movement of the circular and longitudinal muscles found within the digestive tract. This movement occurs in the esophagus, stomach and small intestine.
Along the jejunal intestinal wall are the "circular folds." These folds are thick and stretches towards the "lumen." They function as speed bump control by slowing down the food passage and increasing the surface area necessary for absorption. After being absorbed, they will then be moved forward toward the large intestine.
So, this explains the answer.