Question

1. the lining of the structures in the abdominal and pelvic cavities is the: antrum pancreas jejunum peritoneum 4) the ring of muscles found around the opening between stomach and duodenum is the: ileocecal sphincter anal sphincter pyloric sphincter cardiac sphincter

Explanation:

1. The peritoneum is the lining of the abdominal and pelvic cavities. It covers and supports the internal organs in these cavities.
2. The pyloric sphincter is the ring - shaped muscle located at the opening between the stomach and the duodenum, controlling the passage of food from the stomach to the small intestine.

Answer:

1. peritoneum
2. pyloric sphincter