Lecture 4: GI Organs Flashcards
What are the major GI organs?
Esophagus Stomach Small Intestine Colon Rectum Anal Canal Spleen Pancreas Liver Gall Bladder
What level is the transpyloric plane and what does it pass through?
Subcostal plane?
Transtubercular plane?
Interpsinous plane?
- L1; pyloric sphincter
- L2-3; inferior to costal margin
- L5; iliac tubercles
- S2; ASIS
Esophagus:
Course of organ
Significance of the cardiac notch?
Significance of the inferior esophageal sphincter?
T10: passes through esophageal hiatus
T11: enters stomach and cardiac orifice
- separates esophagus from stomach fundus
- physiologic part of the esophagus that prevents food backflow
Where are the esophageal constriction points?
Superior: cricoid cartilage
Middle: aorta and left main bronchi level
Inferior: diaphragmatic sphincter
Paraesophageal hiatal hernia vs. sliding hiatal hernia:
PHH: peritoneum and fundus of stomach anterior to esophagus; no gastric regurgigation
SHH: esophagus, cardia and fundus protrude through the esophageal hiatus; gastric regurgigation
Stomach:
Course of organ
Greater vs lesser curvature
bilateral upper quadrants
Left end at T10-T11
Right end at L1
-GC: inferior border attached to greater omentum
LC: superior border attached to lesser omentum
What are the parts of the stomach?
Be able to label the image
Fundus, body, pylorus
What organs are found anterior to the stomach?
Left costal margin
Diaphragm
Left lobe of liver
What organs are found superior to the stomach?
Left dome of diaphragm
What organs are found posterior to stomach?
Lesser sac Pancrease Transverse mesocolon Transverse colon Left kidney and adrenal spleen
What is a gastric vagotomy?
-surgically removing parts of the vagus n. to reduce its parietal cell secretion of acid
Truncal vs Proximal vs Selective vagotomy
- remove all vagus n. branching in the stomach + additional GI parts)
- remove all vagus n. branching in stomach only
- remove vagus n. branching to an area of stomach where the parietal cells are (fundus and cardia)
Duodenum:
Course of organ
-Pylorus to duodenojejunal jxn
How would you describe the parts of the duodenum?
Part 1: intraperitoneal
Part 2-4: retroperitoneal
What is the significance of the ligament of treitz?
Continuous with the right crus of the diaphragm that leads to the duodenaljujenal jxn
-helps open the jxn to let food pass through the duodenum to jejunum
Jejunum
Location and level?
Features?
Blood supply?
- left upper quadrant, proximal 2/5 of small intestine, intraperitoneal
- plicae circulares (lots of folds for surface area)
- arterial arcades with long vasa recta
Ilium
Location and level?
Supplied by?
- right lower quadrant,, distal 3/5 of small intestine intraperitoneal
- arterial arcades with short vasa recta
What is the mesentery?
2 layers of peritoneum that connect the intestines to the posterior body wall
What are the parts of the colon?
cecum, appendix, ascending, transverse, descending and sigmoid colon
Appendix
Attached to the cecum at the ascending colon (RLQ)
-has lymphoid nodules (immune function)
What is the classic presentation of acute appy?
-McBurney’s point tenderness and Rovsing’s
-involuntary guarding
Dunphy’s sign (pain when coughing)
-more severe if app. is perforated
What is Ileal (Meckel’s) Diverticulum?
congenital, pouches on the ileum that can become inflamed and mimic appy sx.
Cecum
Where?
Features?
- “beginning” part of the colon
- has the ileocecal valve that regulates what passes into it
What type of organ is the ascending colon?
Transverse colon?
Descending colon?
- retroperitoneal
- intraperitoneal
- retroperitoneal
Volvulus of sigmoid colon:
twisting of sigmoid colon and mesocolon causing obstruction of descending colon or parts proximal to twisted segment = can result in ischemia, so need emergency surgery
Rectum
where?
Features?
- retroperitoneal and subperiotneal in pelvic cavity
- 3 rectal folds (superior, middle and inferior)
Anal canal
Internal vs External anal sphincters
Internal: smooth muscle
External: skeletal muscle
Spleen
Where?
What ligaments are attached to the spleen?
- Left upper quadrant parallel to left ribs 9-11 at mid-axillary line, intraperitoneal
- gastrosplenic and splenorenal ligaments
Pancreas:
Location
L1-L2 level
What are the parts of the pancreas?
Be able to identify on image
Head, neck, body, tail, uncinate process
What are the major ducts of the pancreas?
Identify these in the picture
Main pancreatic duct
Accessory pancreatic duct
What is the hepatopancreatic ampulla?
- merging of the common bile duct and main pancreatic duct
- associated with sphincter of Oddi and major duodenal papilla
Liver:
Location?
surfaces of the liver
right lobe: RUQ, epigastric and RH
left lobe: LUQ
Diaphragmatic and visceral surface
Porta hepatis
Left sagittal feature
Right sagittal feature
Be able to label liver anatomy images on slides
- has hepatic portal a. and v., nerve plexus, hepatic bile duct and lymph
- has ligamentum teres (umbilical v.)
- has gall bladder and IVC
Cirrhosis of the liver
-fatty changes and fibrosis of liver cells, most commonly due to alcohol
Be able to label the biliary tree in the image
Ok
Cholelithiasis
- cholesterol crystals lodged in biliary tree structures
- if hepatopancreatic ampulla is blocked, bile backs up into pancreas and causes pancreatitis
What causes obstructive jaundice?
stones form inside the common bile duct and biliary tree
