L18 - Abdominal Viscera II - Large Intestine and Venous Drainage Flashcards
Cecum
- blind-ended pouch
- covered in peritoneum but no mesentery
- ileocecal (ileocolic) lavle… 1-way
Vermiform Appendix
- 8-10cm long
- aggregations of lymphoid tissue
- no longer necessary - more trouble than functional
- suspended by the mesoappendix (houses A/V)
- variable positions: retrocecal, retrocolic, pelvic
Vermiform Appendix - McBurney’s Point
- point on anterior abdominal wall that is the lateral 1/3 of the distance from the ASIS to umbilicus
- dull P and tender on palpation with inflamed - doctor’s visit, possible Sx
- sharp and intense pain - ambulance, life threatneing
Colon - four parts
- ascending - right upper
- transverse
- descending - left upper
- sigmoid (pelvic)
Colon other two parts?
- left colic flexure (splenic)
- right colic flexure (hepatic)
Colon: features (3)
- teniae coli (singular tenia)
- haustra (singular haustrum)
- epiploic appendages
Muscular components of colon
- taeniae coli
- haustra
taeniae coli
- 3 longitudinal bands of smooth muscle that run along the outer layer of the entire colon
haustra
- series of pouches in the wall of the colon
- created by muscle tone in taeniae coli
- permit expansion and elongation of colon
Peritoneal coverings of the colon: Mesocolon
- Complete covering
- partial covering
- mesoappendix
Complete covering
transverse & sigmoid mesocolon (intraperitoneal)
partial covering
ascending, descedning & rectal mesocolons (retroperitoneal)
mesoappendix
- connects appendix t ileum and cecum
Large intenstine: blood supply - superior mesenteric artery:
-ilecolic
- right colic
- middle colic (rememeber MRI)
Large intenstine: blood supply - inferior mesenteric artery:
- left colic
- sigmoidal
- superior rectal (hemorrhoidal)
(rememeber: I Love Singing Songs)
Large intenstine: blood supply - Marginal artery of Drummnd
anastomoses between right, middle and left colic arteries
- key for collateral circulation or alternative supply
Parts of the pancreas
- tail
- body
- neck
- head
- uncinate process
Large intestine: Venous Drainage
- splenic vein
- hilum of spleen - posterior to tail and body of pancrease - join superior msenteric vein
- drains: spleen, lower esophagus, part of stomach and pancreas
- superior mesenteric vein
- ascends in root of the mesentery - pass anterior to 3rd part of duodenum (transverse) - joins splenic vein posterior to neck of pancreas
- drains: areas suplied by the SMA
- inferior mesenteric vein
- ascends on left posterior abdominal wall - join splenic vein posterior to pancreas
- drains: areas supplied by the IMA
The splenic vein and superior mesenteric vein unite to become the ____ _____ _____
hepatic portal vein
what does the Hepatic portal vein do?
carries nutrients from digestive tract to the liver
What is portosystemic obstruction and what are some common causes?
- the result of obstructed venous return to the liver
- thrombosis, liver cirrhosis, heart failure
Comopnets of the foregut
- esophagus
- stomach
- liver
- gallbladder
- bile ducts
- pancreas
- proximal duodenum
components of the midgut
- distal duodenum
- jejunum
- ileum
- cecum
- appendix
- ascending colon
- proximal 2/3 transverse colon
components of the hindgut
- distal 1/3 transverse colon
- descedning colon
- sigmoid colon
- upper anal canal