The inferior pancreaticoduodenal artery is a branch of the superior mesenteric artery

Superior mesenteric artery

In human anatomy, the superior mesenteric artery arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk, and supplies the intestine from the lower part of the duodenum through two-thirds of the transverse colon, as well as the pancreas.-Location...

 or from its first intestinal branch, opposite the upper border of the inferior part of the duodenum

Duodenum

The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum...

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It courses to the right between the head of the pancreas

Pancreas

The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...

 and duodenum

Duodenum

The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum...

, and then ascends to anastomose with the anterior and posterior superior pancreaticoduodenal artery

Superior pancreaticoduodenal artery

The superior pancreaticoduodenal artery is an artery that supplies blood to the duodenum and pancreas. It is a branch of the gastroduodenal artery, which most commonly arises from the common hepatic artery of the celiac trunk...

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It distributes branches to the head of the pancreas and to the descending and inferior parts of the duodenum.