University:
The University Of Western Ontario
Course:
Biology 2290F | Scientific Method in Biology
Academic year:

2022
Views:

301

Pages:

3
Author:

Kyuwon J.

Region Structures Key Features Foregut Esophagus → 2nd part of duodenum Supplied by celiac trunk Midgut 2nd part of duodenum → 2/3 transverse colon Supplied by SMA Hindgut Last 1/3 of transverse colon → upper anal canal Supplied by IMA ● Esophagus ○ 25 cm muscular tube ○ Transition from skeletal muscle (⅓ of upper body) to smooth muscle ○ Passes diaphragm in T10 position ○ GERD formation may be common surgical issue ● Stomach ○ Fundus body, pylorus ○ Curvature = greater and lesser ○ Gastric (left+right), gastroepiploic arteries ○ Sphincters ■ LES (cardiac), pyloric Region Artery Origin Foregut Celiac trunk Abdominal aorta (T12) Midgut SMA Abdominal aorta (L1) Hindgut IMA Abdominal aorta (L3) ● Small intestine ○ Total length = 6 meters ○ Most nutrients are absorbed here ○ Duodenum ■ C shaped 4 parts= received bile, pancreatic duct ● Superior Duodenum ○ 5cm ○ Runs horizontally to right ○ First few entrance is Intraperiotenal the rest is retropectineal ○ Hepatoduodenal ligaments ○ Gallbladder anteriorly ● Descending Duodenum ○ L1-L3 vertebral level ○ Vertically downward movement ○ Revives from common bile duct +main pancreatic duct through major duodenal palpilla ○ Important for ERCP procedures ● Horizontal/ Inferior Duodenum ○ Middle line of L3 ○ Horizontally to the left ○ Tetroperiotoneal ○ Cross through anteriorly by superior mesenteric artery (SNA) ■ Compression => SMA syndrome ○ Clinical ■ SMA syndrome may be rare but lethal => can cause obstruction ■ Retroperitoneal injuries will affect without peritonitis ● Ascending Duodenum ○ Ascends in L2 level ○ Obliquely upwards to the left ○ Tetropteritoneal ○ Ends in Duodenojejunal flexure ○ Ligaments of Treitz used for distinguishing between upper and lower GI bleeding Part Orientation Peritoneal Landmarks / Notes 1st Horizontal Intraperitoneal (proximal), rest retroperitoneal Ulcers, gastroduodenal artery risk 2nd Vertical (down) Retroperitoneal Receives bile + pancreatic ducts 3rd Horizontal (left) Retroperitoneal Crossed by SMA/vein, SMA syndrome risk 4th Ascending (up-left) Retroperitoneal Ligament of Treitz, UGI vs LGI divide