GI Organs Flashcards
where does the thoracic esophagus pierce the diaphragm?
T10
where does the esophagus enter the stomach at the cardiac orifice?
T11
where does the aorta pass thru the diaphragm?
T12
where does the inferior vena cava pass thru the diaphragm?
T8
sliding hiatal hernia
-esophageal hiatus of diaphragm enlarges or weakens
abdominal esophagus and parts of the stomach (cardia and sometimes fundus) herniate into the thorax
paraesophageal hiatal hernia
i. A defect in diaphragm next to the esophageal hiatus
ii. Permits fundus of stomach to herniate (not usually the esophagus)
1. These occur next to the esophagus, so defect of diaphragm next to the esophagus
2. Fundus comes up next to esophagus
where is stomach fixed?
i. Left end fixed at T10-11 at esophagus
ii. Right end fixed at L1-2 at duodenum
iii. Area b/w is variable—b/c stomach can get larger or smaller
duodenum
- C shaped
- 10 inches long
- located approximately at L1 to L4 vertebral bodies
- starts at the pylorus of the stomach and ends at the duodenal jejunal junction
- further subdivided into 4 parts:
a. superior
b. descending
c. horizontal
d. ascending - secondarily retroperitoneal
superior duodenum
i. starts at pyloric sphincter
ii. about 2 inches long
iii. held in place by the hepatoduodenal ligament
iv. portal V, hepatic A, and bile duct are therefore posterior and superior to this part
v. duodenal bulb—widened area
vi. head of the pancreas is inferior to this part
descending duodenum
i. about 3 inches long
ii. all secondarily retroperitoneal
iii. fundus of the gall bladder, right lobe of the liver, transverse colon are all anterior
iv. R kidney and ureter are posterior
v. Head of the pancreas is medial
vi. Bile and pancreatic ducts enter into the second part of the duodenum at the major duodenal papilla
horizontal duodenum
i. Superior mesenteric A and V and the root of the mesentery cross the anterior surface of the 3rd part of the duodenum
ii. Head of the pancreas is superior
iii. Jejunum is anterior and inferior
ascending diaphragm
i. Becomes intraperitoneal—not covered by parietal peritoneum
ii. Root of the mesentery and jejunum are anterior
iii. Left margin of the aorta and the medial border of the psoas muscle are posterior
iv. 4th part is held in place of the suspensory ligament (or muscle) of the duodenum (of Treitz)
1. suspensory ligament anchors the 4th part of the duodenum to the right crus of a diaphragm
jejunum
a. 8-10 feet
b. 2/5 of free small intestine
c. simple vascular arcades, long vasa recta, more vascular
d. greater diameter, thicker, more plicae circularis
plicae circularis
circular folds that go around jejunum
ileum
a. 10-12 feet long
b. 3/5 of the free small intestine
c. has compound vascular arcades, shorter vasa recta, is less vascular
d. is smaller diameter, thinner wall
e. fewer plicae circularis
meckel’s diverticulum
i. Most common congenital anomaly of the small intestine
ii. Arises from the antimesenteric border of the ileum
iii. Occurs in about 2% of the population
iv. About 2 feet from the ileocecal junction
v. Average about 2 inches long
vi. Remnant of the vitelline duct
vii. Clinically difficult to distinguish from appendicitis
viii. May contain other types of tissues
**usually 2 inches long, occurs 2 feet from ileocecal valve, in about 2% of the population, usually occurs in first 2 years of life, 2 types of epithelia–gastro and intestinal
taenia coli
a. 3 bands of longitudinal muscle on the outside of the colon
i. converge at the root of the appendix
ii. produce houstrae that slow movement of feces
epiploic appendages
i. tags of fat
ii. characteristic of large intestine
cecum
i. no epiploic appendages
ii. blind “pouch” inferior to ileocecal orifice
iii. iliocolic valve is 2 folds that are not a true spincter
iv. ileal papilla is a cone like projection of the ileum into the cecum
v. opening for the appendix is inferior to the ileal papilla
vermiform appendix
i. usually attached to the posteromedial part of the cecum
ii. located at the junction of 3 taenia coli
iii. 9-10 cm long and supported by a mesoappendix
iv. position is variable
ascending colon
- R colic feature—hepatic flexure
- Secondarily retroperitoneal
a. Except lowest part
transverse colon
- Left colic flexure (splenic flexure)
2. Intraperitoneal—transverse mesocolon