Page:Laboratory Manual of the Anatomy of the Rat (Hunt 1924).djvu/94

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
80
ANATOMY OF THE RAT

of the median lobe. The round ligament (ligamentum teres hepatis) is the ventral thickened border of the falciform ligament. It enters the dorsal end of the fissure in the median lobe. The left triangular ligament is a triangular sheet connecting the dorsal edge of the left lateral lobe with the diaphragm. It unites with the diaphragm along a line running from the vena cava to the left and to the dorsal margin of the diaphragm. The right triangular ligament is a comparatively broad sheet connecting the dorsal side of the right lateral lobe with the diaphragm.

The rat's liver possesses no gall bladder for storing the bile, the digestive secretion of the liver. The hepatic ducts convey the bile from the liver lobes to the bile duct (ductus choledochus) which then passes along the duodenohepatic omentum, ventral to the portal vein. The duct traverses the dorsal side of the pancreas and enters the mensenterial side of the duodenum about three centimeters from the pylorus. The liver receives arterial blood from the hepatic artery, and venous blood from the alimentary canal through the portal vein. Food substances absorbed from the alimentary canal are carried to the liver through this vein. Carbohydrates are stored there in the form of glycogen. Blood leaving the liver enters the inferior vena cava through the hepatic veins.

MESENTERIES OF THE ALIMENTARY CANAL

The digestive organs of the vertebrates are connected with one another and with the walls of the abdominal cavity by membranes. The membranes uniting the organs with the dorsal abdominal walls are called mesenteries. Of these the mesogastrium supports the stomach, the mesentery proper the intestine, and the mesocolon supports the colon. The alimentary canal in all vertebrates except