Duodenum

Question 1

Describe the duodenum.

Answer 1

• a C-shaped tube which surrounds the head of the pancreas
• the shortest (25 cm) and widest part of the small intestine
• contains duodenal (Brunner) glands: secrete an alkaline mucus, which is dilute; it neutralizes gastric acid
• entirely retroperitoneal except for the duodenal cap, which is free (mobile)
• the superior mesenteric artery and vein pass anterior to the third part

Question 2

What are the parts of the duodenum?

Answer 2

• superior (first) part
• descending (second) part
• inferior or horizontal (third) part
• ascending (fourth) part

Question 3

Describe the superior/first part of the duodenum.

Answer 3

• runs to the right

- the beginning of the superior part is called the duodenal cap (ampulla)

Question 4

Describe the descending/second part of the duodenum.

Answer 4

contains the junction of the foregut and midgut, where the bile duct and pancreatic duct empty

Question 5

Describe the inferior or horizontal/third part of the duodenum.

Answer 5

• the longest part

- runs to the left, anterior to the inferior vena cava, aorta, and vertebral column

Question 6

Describe the ascending (fourth) part of the duodenum.

Answer 6

ascends to the left of the aorta and terminates at the Duodenojejunal flexure

Question 7

What is the suspensory muscle (ligament) of the duodenum?

Answer 7

a fibromuscular band which extends from the diaphragm to the duodenojejunal flexure

Question 8

What is the blood supply to the duodenum?

Answer 8

• superior pancreaticoduodenal artery (from gastroduodenal artery)
• supraduodenal artery (from gastroduodenal artery)
• inferior pancreaticoduodenal artery (from superior mesenteric artery) - supplies the third and fourth parts

Question 9

What is the innervation of the duodenum?

Answer 9

autonomic fibers from the celiac and superior mesenteric plexuses

Question 10

Describe duodenal ulcer.

Answer 10

• mucosa in the duodenum is eroded to form a crater-like depression
• most commonly located in the duodenal cap
• ulcers may perforate, allowing contents to escape into the peritoneal cavity, causing peritonitis
• fluid travels from the subhepatic recess to the right paracolic gutter, to the right iliac fossa
• due to their proximity, the liver, pancreas, and gallbladder are often damaged by a perforated duodenal ulcer
• erosion of the gastroduodenal artery by a perforated duodenal ulcer can result in severe hemorrhage

Question 11

What is the chiropractic note concerning gastric and duodenal ulcers?

Answer 11

• both gastric and duodenal ulcers have been found to be associated with midthoracic subluxations
• the greater splanchnic nerve supplies sympathetic innervation to the stomach and duodenum above the entrance of the common bile duct