Abdomen 1.3 Flashcards
Where does the abdominal aorta enter the abdomen?
via the aortic hiatus (T12 vertebral level) in the diaphragm
When does the abdominal aorta divide into common iliac arteries?
anterior to L4 vertebra
Where does the abdominal aorta supply blood to?
abdominopelvic viscera and posterior abdominal wall
What are the 3 unpaired vessels supplying the GI tract?
- Celiac
- Superior mesenteric
- Inferior mesenteric
What are the paired branches to glandular structures?
- middle suprarenal
- left and right renal arteries
- left and right gonadal arteries
What are the parietal branches to the posterior abdominal wall?
- Inferior phrenic arteries
- 4 pairs of lumbar arteries
- a small median sacral artery (our “caudal” artery).
What is a common site for aortic aneurysms?
- abdominal aorta inferior to the origin of the renal arteries and above the aortic bifurcation
- Iliac arteries also usually involved
Where do the suprarenal gland receive their arterial blood supply from?
- from inferior phrenic arteries
- directly from middle suprarenal arteries arising from the aort
- from inferior suprarenal arteries arising from the renal vessels
What type of organs are the suprarenal (adrenal) gland and the kidneys?
retroperiteneal
Which kidney is higher?
right kidney lies slightly lower than the left kidney, owing to the presence of the liver on the right side
What shape is the right adrenal gland?
usually is pyramidal in shape
What shape is the left adrenal gland?
usually semilunar in shape
Why are there lots of arteries and/or veins associated with the kidneys?
Because of the segmental development of the kidneys and their lobulated appearance
At what level does the inferior vena cava pierce the diaphragm?
T8 and enters right atrium of heart
What veins drain blood from the liver into the inferior vena cava just inferior to the diaphragm?
2 or 3 hepatic veins
What do principal tributaries of the inferior vena cava correspond to?
many of the arterial branches arising from the abdominal aorta
What are some of these tributaries?
- the common iliac veins
- pairs of lumbar veins
- gonadal (testicular or ovarian) veins
- renal veins
- azygos vein
- suprarenal veins
- inferior phrenic veins
- hepatic veins
What forms the portal venous system?
Veins draining the gastrointestinal tract, its accessory organs (gallbladder and pancreas) and the spleen
Which veins do not have valves?
- Veins vary in number and arrangement and possess numerous connections with veins lying superficial or deep
- and with veins of specialized systems such as the portal system draining the gastrointestinal tract
- these veins do not have valves
- blood flow may occur in either direction depending on the pressure gradient propelling the blood
How is the hepatic portal vein formed?
union of the splenic vein and superior mesenteric vein.
What are important portacaval anastomotic sites?
- sites around the esophagus
- the paraumbilical region
- the rectum,
- where portions of the gastrointestinal tract are in a retroperitoneal position.
How does blood still reach the heart if portal blood flow is decreased or prevented from flowing through the liver?
important portacaval anastomoses
What happens if the inferior vena cava is partially compressed or obstructed?
venous blood can flow via the portacaval anastomoses into the portal system of veins
What is the parietal and visceral peritoneum?
Parietal peritoneum lines the inner aspect of the abdominal walls and reflects onto the viscera as visceral peritoneum
What does the greater omentum do if a portion of the peritoneal cavity or its contents becomes inflamed?
the greater omentum can migrate to the site of inflammation and wall off the site by forming an adhesion, potentially protecting the remainder of the cavity (wall off infection site)
What is the greater omentum a site for?
the metastatic spread of cancer from multiple primary sites
Where is the lesser sac?
residing posterior to the stomach and anterior to the retroperitoneal pancreas
How can you enter the lesser sac?
through the epiploic foramen of Winslow
What lies anterior to the epiploic foramen?
hepatoduodenal ligament, which is a portion of the lesser omentum (the other part is the hepatogastric ligament)
What is in the hepatoduodenal ligament?
- the proper hepatic artery
- the common bile duct
- the portal vein
What is secondary retroperitneal?
- pancreas
- duodenum
What could a perforated gastric ulcer in the posterior wall of the stomach lead to?
spill gastric contents into the lesser sac, and its acidic juices may erode into the pancreas
What could cancer of the pancreas invade?
the duodenum, stomach, or spleen because of its close proximity to these structures
Where is the omental bursa/lesser sac?
posterior to the stomach and anterior to the pancreas, which lies retroperitoneally.
What is the rest of the abdominopelvic cavity referred to?
greater sac
Where is the portal triad?
In the hepatoduodenal ligament (part of lesser omentum and other part is hepatogastric ligament)
What are the aorta and IVC?
retroperitineal
What is posterior to the portal triad?
access the inferior vena cava
What could cancer/trauma of pancreas lead to?
implications of duodenum, stomach, spleen, left kidney and adrenal gland, and aorta and inferior vena cava
How does bile leave the liver?
by the right and left hepatic ducts, draining into a common hepatic duct
How does the common hepatic dict drain?
via the cystic duct into the gallbladder, which concentrates and stores bile
How is the gallbladder stimulated to contract?
autonomic nerves and cholecystokinin
What does gallbladder contracting lead to?
sending bile down the cystic duct
How does bile flow?
through the common bile duct to the major duodenal papilla which empties into the descending duodenum
What happens at this location to the common bile duct?
joins the main pancreatic duct to form the hepatopancreatic ampulla of Vater
How common are gallstones?
occur in 10% to 20% of adults
What are risk factors of gallstones?
increased age, obesity, and being female
What are two different types of gallstones?
- 80% of gallstones are cholesterol stones
- 20% are pigment (bilirubin calcium salts) stones
What can gallstones lead to?
- block the flow of bile from the gallbladder to the duodenum
- cause inflammation (cholecystitis)
- or block the hepatopancreatic ampulla and impede exocrine secretion from the pancreas
Where is the pain of acute cholecystitis felt?
- felt in the right upper abdominal quadrant
- radiating laterally just beneath the right breast
- to the back just below the inferior angle of the right scapula
What does visceral peritoneum do on the liver?
reflects off the liver in the form of the falciform ligament and the coronary ligaments
What do the falciform and coronary ligaments reflect off?
the right and left lobes of the liver and onto the underlying diaphragm
What is the bare area of the liver?
marks the portion of the liver not covered by visceral peritoneum because it is in direct contact with the diaphragm
What is the round ligament of the liver?
the obliterated left umbilical vein
When is the round ligament of the liver visible?
in the free margin of the falciform ligament
What does the round ligament join?
ligamentum venosum
What is the ligamentum venosum?
- fused ductus venosus from the fetus
- before birth, this passageway allows umbilical blood coming from the placenta to bypass the liver and drain directly into the inferior vena cava and pass into the right atrium of the fetal heart
What is the function of the liver?
- production and secretion of bile
- Storage of nutrients
- production of cellular fuels, plasma proteins and clotting factors;
- detoxification
- phagocytosis
What is cirrhosis?
largely irreversible disease of the liver
What are the causes of cirrhosis?
- alcoholic liver disease (60% to 70% of cases)
- viral hepatitis
- biliary diseases
- genetic hemochromatosis
- cryptogenic cirrhosis
