| duodenum jejunum ileum main function: absorption of nutrients from ingested materials |
| first + shortest (25 cm) part widest + most fixed part C-shaped course around head of pancreas starts @pylorus on right side; ends @duodenojejunal junction on left side
(duodenojejunal flexure = L2 vertebra, 2 - 3 cm L. of midline) (mostly fixed by peritoneum to structures on post. ab. wall) |
| Superior (first) part: Descending (second) part: Horizontal (third) part: Ascending (fourth) part: |
Which part of the duodenum has a mesentery and is mobile? | ampulla (duodenal cap) (distal 3 cm of the superior part are immobile –> retroperitoneal) |
superior part of the duodenum ascends from the pylorus and is overlapped by what structures? | liver + gallbladder (Peritoneum covers its anterior aspect, but it is bare of peritoneum posteriorly, except for the ampulla) |
The proximal part of the superior duodenum has what 2 structures attached to it? | - hepatoduodenal ligament (part of the lesser omentum) attached superiorly |
The bile and main pancreatic ducts enter the posteromedial wall of whiche duodenal section? | DESCENDING (lies to right of/parallel to the IVC; curves inferiorly aroudn head of pancreas) |
| |
| |
| transversely to the left; passing over the IVC, aorta, + L3 vertebra inferior to head of pancreas + uncinate process posteriorly = separated from vertebral column by: right psoas major, IVC, aorta, + right testicular or ovarian vessels
|
| superiorly/along left side of aorta; reaches inferior border of body of pancreas curves anteriorly to join the jejunum at the duodenojejunal junction ligament of Treitz = supportive suspensory muscle of duodenum
|
| composed of a slip of skeletal muscle from diaphragm + a fibromuscular band of smooth muscle from 3rd + 4th parts of duodenum Contraction = widens angle of duodenojejunal flexure = movement of the intestinal contents
|
| arise from celiac trunk + superior mesenteric artery celiac trunk: supplies duodenum proximal to the entry of the bile duct via gastroduodenal artery + branch, superior pancreaticoduodenal artery
Superior Mesenteric Artery: |
pancreaticoduodenal arteries | lie in the curve b/t duodenum + head of the pancreas supply both structures anastomosis of superior + inferior pancreaticoduodenal arteries (@level of entry of bile duct), is formed between the celiac + superior mesenteric arteries
–THIS IS THE JUNCTION OF THE EMBRYOLOGICAL FORGUT/MIDGUT– proximally, blood supply = celiac trunk distally, blood supply = superior mesenteric artery (to L. colic flex.)
|
| follow the arteries and drain into the portal vein some directly, others indirectly (thru superior mesenteric + splenic veins)
|
lymphatic vessels of the duodenum | - anterior lymphatic vessels: drain into the pancreaticoduodenal lymph nodes (along superior + inferior pancreaticoduodenal arteries) + into pyloric lymph nodes (along gastroduodenal artery) - posterior lymphatic vessels: pass posterior to the head of the pancreas, drain into superior mesenteric lymph nodes - Efferent lymphatic vessels: drain into celiac lymph nodes |
| derive from vagus + greater and lesser (abdominopelvic) splanchnic nerves by way of celiac + superior mesenteric plexuses conveyed to the duodenum via periarterial plexuses extending to the pancreaticoduodenal arteries
|
| inflammatory erosions of the duodenal mucosa (65%) occur in posterior wall of superior part, within 3 cm of pylorus occasionally, ulcer perforates duodenal wall = permitting contents to enter peritoneal cavity = peritonitis
(ex. erosion of the gastroduodenal artery = severe hemorrhage +peritonitis) |
Which structures may become adherent to the inflamed duodenum and also become ulcerated as the lesion continues to the tissue that surrounds it? (due to close proximity) | |
| If a loop of intestine enters this fossa, it may strangulate |
