Duodenum, Pancreas, Spleen Flashcards
Where does the small intestine extend from and what are its parts? How does it change throughout?
From pyloric orifice of stomach to ileocecal valve. It is 6-7m long and divided into duodenum, jejunum and ileum
It becomes narrower throughout
What is the duodenum and its four parts? Which are peritoneal?
Shortest, widest, and most fixed part of small intestine. 1. Superior - initial part is peritoneal 2. Descending 3. Horizontal 4. Ascending - tail is peritoneal Rest is retroperitoneal
What is the superior part of the duodenum and its two regions?
LV1 level - first part of duodenum, which connects the pyloric orifice to the descending duodenum. It is the most movable part, and is exposed to high acidity.
- Proximal region - relatively mobile and acidic, attaches to hepatoduodenal ligaments and the greater omentum
- Distal region - It surface is corrugated (ridged) has no mesentery and is immobile. It is retroperitoneal
What is the smooth part of the superior duodenum called? What clinical correlation can occur here and why?
Ampulla, duodenal cap, or bulb. It is the proximal superior duodenum.
Duodenal ulcers occur here as it receives acidic exudates from the stomach. May lead to peritonitis
What is related anteriorly, posteriorly, superiorly, and inferiorly to the superior duodenum?
Anterior: Quadrate lobe of liver = gall bladder
Posterior: Bile duct, portal vein, inferior vena cava, gasroduodenal artery
Superior: NECK of gall bladder
Inferior: NECK of pancreas
Where is the descending part of the duodenum?
Second part, it is retroperitoneal, and passes along right sides of LV1 to LV3. It passes to the right and parallel to the inferior vena cava during its descent.
What is the significance of the descending part of the duodenum?
The bile duct and main pancreatic duct enter the posteromedial wall, about 2/3 along its length. THey unit to form the hepatopancreatic ampulla, which opens on the major duodenal papilla
In some people, the bile and pancreatic ducts open separately into this area
What are the anterior, posterior, and medial relationships of the descending duodenum?
Anterior: Transverse colon + mesocolon, some coils of small intestine
Posterior: Hilus of right kidney, renal vesels, ureter, and right psoas major muscle
Medial: Head of pancreas, pancreatic + bile ducts
What is the horizontal part of the duodenum?
3rd part, runs right to left along LV3 retroperitoneally, passing anterior to IVC and abdominal aorta.
What are the anterior, posterior, and superior relationships of the horizontal part of the duodenum?
Anterior: Superior mesenteri artery + vein, coils of small intestine
Posterior: Right psoas major, IVC, aorta, right ureter
Superior: Head of pancreas, superior mesenteric vessels
What is the ascending part of the duodenum?
4th part, ascends left side of aorta at level of LV2. It bends anteriorly and joins the jejunum at the duodenojejunal flexure. The distal end is peritoneal and movable with the jejunum
What supports the duodenojejunal flexure?
Suspensory muscle / ligament of the duodenum, arising from right crus of diaphragm and attached to ascending duodenum
What are the anterior, posterior, and medial relationships to the ascending duodenum?
Anterior: Beginning of the root of the mesentery, coils of jejunum
Posterior: Left psoas major muscle, left margin of the aorta
Medial: Head of pancreas
Superior: Body of pancreas
What are the four recesses formed by the peritoneal folds at the duodenojejunal junction?
- Superior duodenal
- Inferior duodenal
- Retroduodenal - (between the super and inferior duodenal recesses)
- Paraduodenal - lateral side away from ascending duodenum, carries inferior mesentery vein in its fold
What is the primary blood supply to the duodenum?
- Superior pancreaticoduodenal (PD) - branch of gastroduodenal supplying proximal half of duodenum
- Inferior pancreaticoduodenal - branch of superior mesenteric supplying distal half of duodenum
Where do the superior and inferior PD arteries anastomose?
In the head of the pancreas to form an arterial arcade. Branches of these arteries supply the duodenum
Where might the superior part of the duodenum get blood?
Supraduodenal (from gastruoduodenal), right gastric, gastro-omental, or gastroduodenal arteries, since it is in close attachment to the stomach
What is the lymphatic and venous drainage of duodenum?
Veins follow arteries, and will drain into venous portal system by superior mesenteric
Lymph: PD nodes, pyloric nodes, superior mesenteric nodes all drain into CELIAC nodes