The coronary ligament is a layer of connective tissue that attaches to the liver. It is an offshoot of the peritoneum, the membrane within the abdominal cavity that houses its contents, which include not only the liver but the lower esophagus, stomach, gallbladder, spleen, and intestines. So that these organs are not simply floating about within the peritoneum, connective tissue essentially chains them to that membrane. The coronary ligament, specifically, links the liver to the underside of the diaphragm along the ceiling of the abdominal cavity.
If the peritoneum were opened through the abdomen to expose its contents, the liver would be visible as the topmost of these organs, partially covering the right side of the stomach. Directly above it is the diaphragm, the rounded layer of muscle that spans the underside of the ribcage and forms the ceiling of the abdominal cavity. Most of the liver’s surface area that is adjacent to the diaphragm, called the diaphragmatic surface, is not in direct contact with the diaphragm. Instead, an offshoot of the peritoneum known as a reflection fills the space between the two. This is the coronary ligament, and it is one of several such reflections linking the liver to the diaphragm.
There are two portions of the coronary ligament, known as the superior and inferior layers. The superior, or top, layer penetrates the space between the liver and diaphragm from the front and covers most of the diaphragmatic surface of the liver, which is convex in relation to the concave shape of the diaphragm. Approaching from below and behind is the inferior layer, another reflection that projects from a two-layered section of peritoneum called the lesser omentum and fills the space between the back of the liver and the diaphragm.
A small surface area on the top rear aspect of the liver between the superior layer of coronary ligament above and the inferior layer behind is not covered by any peritoneal membrane. Therefore the liver directly abuts the diaphragm here, along a surface known as the bare area of the liver. Where the two layers of coronary ligament come together on either side of the bare area, they form the right and left triangular ligaments. To the front of the triangular ligaments, where the superior layer of coronary ligament ends near the front border of the diaphragm, is another peritoneal reflection: the falciform ligament. Together, these reflections of the peritoneum hold the liver in its place in the peritoneal cavity.