Gastrointestinal Tract Flashcards
What are the three branches of the coeliac trunk?
Splenic artery
Left gastric artery
Common hepatic artery
Which ligament marks the duodenojejunal junction?
Ligament of Treitz
What is the blood supply to the appendix?
Ileocolic artery (branch of the SMA)
What is the blood supply to the ascending colon?
Right colic artery (branch of the SMA)
What is the blood supply to the transverse colon?
Proximal 2/3 - middle colic artery (branch of SMA)
Distal 1/3 - left colic artery (branch of IMA)
What are the attachments of the lesser omentum?
Liver
Lesser curvature of the stomach
What are the attachments of the greater omentum?
Transverse colon
Greater curvature of the stomach
The rectum begins at which spinal level?
S3
How many bones make up the sacrum?
5
What are the peritoneal coverings of the upper 1/3 of the rectum?
Front and sides
What are the peritoneal coverings of the middle 1/3 of the rectum?
Front
What are the peritoneal coverings of the lower 1/3 of the rectum?
No peritoneum
Which epithelial cell type is found in the upper half of the anal canal?
Columnar
Which epithelial cell type is found in the lower half of the anal canal?
Non-keratinised stratified squamous
What is the structure of the internal anal sphincter
Continuation of the inner circular muscle of the rectum
Smooth muscle, under autonomic control
What is the nerve supply to the internal anal sphincter?
Inferior hypogastric plexus
What is the structure of the external anal sphincter?
Deep, superficial and subcutaneous portions
The external anal sphincter attaches to which structures?
Perineal body and coccyx
What is the nerve supply to the external anal sphincter?
Inferior rectal nerve (branch of the pudendal)
What is the porta hepatis?
Deep groove on posterior surface of the liver
Contains: hepatic artery, portal vein, hepatic bile ducts
What is the origin of the superior rectal artery?
Inferior mesenteric artery
What is the origin of the middle rectal artery?
Anterior division of the internal iliac artery
What is the origin of the inferior rectal artery?
From the internal pudendal artery
Branch of anterior division of the internal iliac artery
What is the lymphatic drainage of the rectum?
Internal iliac nodes
Which GI structures have mesenteries?
Small intestines
Sigmoid colon
Transverse colon
Which veins form the hepatic portal vein?
Superior mesenteric vein
Splenic vein
Which epithelial cell type is found in the rectum?
Columnar
What is meant by Hilton’s line?
Transition from non-keratinised ss epithelium to keratinised stratified squamous epithelium at the anal orifice
What is meant by the dentate/pectinate line?
Transition upper two thirds of anal canal (derived from endoderm) from lower third of anal canal (derived from ectoderm)
The fibres of the deep external anal sphincter blend with which muscle?
Puborectalis (part of the levator ani)
What are the boundaries of the epiploic foramen?
Superior: caudate lobe of the liver
Inferior: Duodenum
Anterior: Portal Vein
Posterior: IVC
