Chapter 12 and 16: The Portal Vein and the Pancreas

Portal Splenic Confluence

Area just posterior to the neck of the pancreas, where the splenic vein meets the superior mesenteric vein. Together, these veins form the portal vein.

Pancreaticoduodenal Arteries

Arteries that supply the head of the pancreas and part of the duodenum with blood. Part of the pancreatic arcades.

Pancreatic Body

Bordered right laterally by the pancreas neck, left laterally by the pancreas tail, anteriorly by the posterior wall of the stomach, and posteriorly by the splenic vein. Considered the largest portion of the pancreas.

Alpha Cells

Cells that account for 15% to 20% of pancreatic endocrine tissue and produce the hormone glucagon.

Delta Cells

Cells that account for approximately 5% of the pancreatic endocrine tissue that produces the hormone somatostatin.

Epsilon Cells

Cells that account for less than 1% of pancreatic endocrine cells, and produce the hormone ghrelin, which may affect blood sugar regulation.

Pancreatic Juice

Composed of enzymes produced by acini cells in the pancreas that help digest fats, proteins, carbohydrates, and nucleic acids.

Portal Triad

Composed of hepatic arteries and bile ducts that run alongside portal veins in triads surrounded by a sheath of connective tissue. The triads radiate throughout the liver.

Beta Cells

Constitute 60% to 70% of the pancreatic endocrine cells that produce insulin.

Superior Mesenteric Vein

Courses from inferior to superior and drains the small intestine and portions of the large intestine via several smaller branches. Unites with the splenic vein posterior to the neck of the pancreas to form the portal vein.

Ampulla of Vater

Dilatation in the second portion of the duodenum, where the common bile duct and pancreatic ducts enter to discharge substances that aid in the digestive process.

Common Bile Duct (CBD)

Distal portion of the biliary tract that transports and then discharges bile into the duodenum as needed to aid the digestive process.

Splenic Vein

Drains the spleen and courses from lateral to medial directly posterior to the tail, body, and neck of the pancreas, where it unites with the superior mesenteric vein to form the portal vein.

Suprapancreatic Splenic Artery

First 3 cm section of the artery as it originates from the celiac axis.

Gastroduodenal Artery

First brach of the common hepatic artery. Courses along the anterolateral aspect of the pancreas head just right lateral to the pancreas neck, where it divides into anterior and posterior superior pancreaticoduodenal branches. Supplies blood to the head of the pancreas and the duodenum.

Main Portal Vein

Formed by the union of the splenic vein and the superior mesenteric vein posterior to the neck of the pancreas. Along with its tributaries, it delivers blood from the spleen and gastrointestinal tract tot he liver for metabolism and detoxification. Divides into the right and left branches.

Islets of Langerhans

Groups of alpha, beta, and delta endocrine cells in the pancreas that produce insulin.

Glucagon

Hormone produced by alpha cells in the pancreas that causes the release of glucose to meet the immediate energy needs of the body.

Somatostatin

Hormone produced by alpha cells in the pancreas that inhibits the production of insulin and glucose.

Insulin

Hormone produced by beta cells in the pancreas that causes glycogen formation from glucose in the liver.

Hilum

Indentation, depression, or pit on an organ forming a doorway or area of entrance and exit for vessels, ducts, and nerves; also called hilus.

Pancreatic Tail

Left lateral to the pancreas body and aorta and extends to the hilum of the spleen. Situated between the stomach anteriorly and left kidney posteriorly. The splenic vein runs along its posterosuperior surface. May lie higher, lower, or on an even level with the body.

Pancreatic Head

Lies right lateral to the superior mesenteric vein; cradled in the C-loop of the duodenum; directly anterior to the inferior vena cava.

Duct of Wirsung

Main pancreatic duct. Transports and discharges pancreatic juice into the duodenum through the ampulla of Vater to aid the digestive process.

Sphincter of Oddi

Muscle surrounding the ampulla of Vater that controls the flow of pancreatic juice from the pancreas and bile from the biliary tract into the duodenum.

Gamma Cells

Pancreatic Polypeptide (Pp) cells that comprise less that 5% of pancreatic endocrine ells and may affect blood sugar regulation.

Duct of Santorini

Pancreatic accessory duct that enters the duodenum approximately 2 cm superior to the duct of Wirsung.

Uncinate Process

Posteromedial projection of the pancreas head that lies directly posterior to the superior mesenteric vein and and directly anterior to the inferior vena cava or in some cases, due to its size, the abdominal aorta.

Acini Cells

Produce pancreatic juice that is composed of enzymes to help digest fats, proteins, carbohydrates, and nucleic acids.

Endocrine

Produces and secretes hormones directly into the bloodstream with a ductal system.

Exocrine

Produces and transports pancreatic juice via ducts to aid in digestion.

Prehilar Splenic Artery

Section of the artery before it enters the hilum of the spleen.

Prepancreatic Splenic Artery

Section of the artery before it leaves the pancreas.

Pancreatic Splenic Artery

Section of the artery located within the pancreas.

Pancreatic Neck

Situated between the pancreatic head and body immediately anterior to the superior mesenteric vein. At a slightly higher level, it lies anterior to the portal splenic confluence.

Splenic Artery

Supplies the body and tail of the pancreas with blood. From its origin at the celiac axis it runs along the superior edge of the pancreas body and tail parallel to the splenic vein.

Left Portal Vein

The left branch of the main portal vein. Courses to the left and branched into medial and lateral subdivisions that give off multiple subdivisions.

Right Portal Vein

The right branch of the main portal vein. Courses to the right and branches into anterior and posterior subdivisions that give off multiple subdivisions.

Pancreatic Arcades

Vascular connections between the pancreaticoduodenal, hepatic, splenic, and superior mesenteric arteries that supply blood to the head of the pancreas.