Diaphragmatic surface

The diaphragmatic surface of the liver is the convex portion that lies adjacent to the diaphragm. It faces cranially and slightly dorsally. This surface is generally smooth and molded to the diaphragm’s concavity. It is partially covered by the peritoneum except for the bare area, which is directly in contact with the diaphragm.

Species-wise Comparison

1. Dog and Cat (Carnivores)

In carnivores, the liver is relatively large and subdivided into distinct lobes. The diaphragmatic surface is rounded and closely apposed to the diaphragm. Visible lobes on this surface include:

• Left lateral and medial lobes

• Quadrate lobe

• Right medial and lateral lobes

• A part of the caudate lobe

The falciform ligament is well developed in young animals and visible on this surface.

2. Horse (Equine)

In horses, the liver is asymmetrical, predominantly located on the right side of the abdomen. The diaphragmatic surface lies against the right diaphragm and costal wall. Visible lobes include:

• Undivided left lobe

• Quadrate lobe

• Right lobe

• Caudate lobe (partly)

The falciform ligament is often small or vestigial in adults.

3. Cattle (Bovine)

In ruminants, the large rumen displaces the liver to the right side. The diaphragmatic surface therefore faces craniodorsally and somewhat leftward. On this surface, only the right, quadrate, and caudate lobes are typically visible. The left lobe is obscured by the rumen.

4. Sheep and Goat (Small Ruminants)

Similar to cattle, but with less liver displacement. The left lobe may be partially visible dorsally on the diaphragmatic surface. The organ lies largely against the diaphragm and right thoracic wall.

5. Pig (Porcine)

In pigs, the liver is more symmetrically positioned. The diaphragmatic surface lies flat against the diaphragm and the ventral abdominal wall. All lobes except the caudate process are visible:

• Left lateral and medial

• Right lateral and medial

• Quadrate lobe

Key Anatomical Relations

• The bare area of the liver lacks peritoneal covering and is in direct contact with the diaphragm.

• The caudal vena cava traverses this surface in a depression called the caval groove (groove for vena cava).

• The phrenic nerve and caudal vena cava pass through the diaphragm in close proximity to this surface.

• The coronary ligament secures the liver to the diaphragm at the bare area.

Clinical Relevance

• The diaphragmatic surface is important during diagnostic imaging, such as ultrasound.

• In ruminants, a right-sided approach is used for liver biopsy due to the liver’s displacement.

• Liver diseases affecting the diaphragmatic surface may impinge on respiratory function due to proximity to the diaphragm.