Anatomy of GI Bleeding Flashcards
how many paracolic gutters are there?
two, right and left
where are the paracolic gutters found?
between the lateral edge of the ascending/descending colon and the abdominal wall
what are the paracolic gutters part of?
the greater sac of the peritoneal cavity
which flexure of the colon lies more superiorly?
splenic
what are the teniae coli?
3 distinct longitudinal bands of thickened smooth muscle
where do the teniae coli run?
from the caecum to the distal end of the sigmoid colon
what causes the formation of haustra?
tonic contraction of the teniae coli
where do the caecum and appendix lie?
in the right iliac fossa
what is the most common position of the appendix?
retrocaecal
where is the appendiceal orifice found?
on the posteromedial wall of the caecum
where does the appendiceal orifice correspond to?
mcburney’s point on the anterior abdominal wall
where is mcburney’s point?
a third of the way between the right ASIS and the umbilicus
where does the sigmoid colon lie?
the left iliac fossa
what is the mesentery attached to the sigmoid colon called?
the sigmoid mesocolon
why does the sigmoid colon have a large degree of movement?
it has a long mesentery
what is there a risk of due to the length of the sigmoid mesocolon?
sigmoid volvulus
what is sigmoid volvulus?
when the sigmoid colon twists around itself
what can sigmoid volvulus cause?
obstruction and infarction if not treated
is the abdominal aorta intra or retro peritoneal?
retroperitoneal
where does the abdominal aorta lie?
midline
anterior to vertebral bodies
left of the IVC
what are the three midline branches of the abdominal aorta?
celiac trunk
superior mesenteric artery
inferior mesenteric artery
what is supplied by the celiac trunk?
foregut organs
what is supplied by the superior mesenteric artery?
midgut organs
what is supplied by the inferior mesenteric artery?
hindgut organs
what do the lateral branches of the abdominal aorta supply?
kidneys and adrenal glands
gonads
body wall
what does the abdominal aorta bifurcate into?
the common iliac arteries
what does a common iliac artery bifurcate into?
internal and external iliac arteries
what exists between branches of the superior mesenteric artery and the inferior mesenteric artery?
arterial anastomoses
name the main arterial anastomoses between the SMA and the IMA
marginal artery of drummond
what marks the end of the hind gut and where is this found?
the pectinate line
halfway through the anal canal
what artery supplies the proximal half of the anal canal?
the inferior mesenteric artery
what artery supplies the distal anal canal?
the internal iliac artery
what is haematemesis?
vomiting up blood
what are varices?
abnormal, dilated veins
what are the bodies two main venous systems?
hepatic portal venous system
systemic venous system
what does the hepatic portal venous system do?
drains venous blood from absorptive parts of the GI tract to the liver for cleaning
what does the systemic venous system do?
drains venous blood from all other organs and tissues into the inferior vena cava
is the IVC intraperitoneal or retroperitoneal?
retroperitoneal
what is the role of the IVC?
drains clean blood from the hepatic veins into the right atrium
what is the role of the splenic vein?
drains blood from foregut structures to the hepatic portal vein
what is the role of the superior mesenteric vein?
drains blood from midgut structures to the hepatic portal vein
what is the role of the inferior mesenteric vein?
drains blood from hindgut structures to the splenic vein
what are anastomoses between the systemic and portal venous systems called?
portal systemic anastomoses
how many portal systemic anastomoses are there?
three
where are the three portal systemic anastomoses found?
distal end of the oesophagus
skin around the umbilicus
rectum/anal canal
what is the clinical term given to increased blood pressure in the portal veins?
portal hypertension
