Final answer:
The ileocecal sphincter, which controls the flow of digested material from the small intestine to the large intestine, is made up of smooth muscle.
Step-by-step explanation:
The ileocecal sphincter is composed of smooth muscle. It functions at the junction between the small intestine and the large intestine to control the flow of digested material. The sphincter's contractions are involuntary, and its relaxation is controlled by both nerves and hormones. The ileocecal valve remains typically constricted and relaxes to allow the passage of food residue into the cecum of the large intestine. The sphincter is part of a group of muscles known as anatomical sphincters, which surround the lumens of vessels or hollow organs to regulate flow when contracted.