In the cat, the esophagus lies behind the trachea (as it does in humans). The esophagus provides a passageway for food to the stomach, which lies below the diaphragm in the abdominal_cavity.
The liver and gall_bladder are below the diaphragm and conceal part of the stomach. If you reflect the liver you can find the pancreas lying in the mesentery that supports the intestines.
The small_intestine (duodenum, jejunum, and ileum) extends from the base of the stomach to the cecum of the colon.
The spleen (which is lymphatic, not digestive) is clearly visible on the left side of the abdomen.
Mesenteries are double-layered extensions of the peritoneum that provide support for the abdominal organs. Mesenteries provide routes for blood vessels, lymphatics and nerves to reach the digestive organs. They also hold organs in place and store fat. There are dorsal as well as ventral mesenteries. The greater and lesser omenta (sing: omentum) are examples of mesenteries.
The omenta extend from the upper curvature (lesser_curvature) of the stomach (lesser_omentum), and from the greater_curvature of the stomach down over the abdominal organs (greater_omentum).