Abdominal Viscera Flashcards
At what vertebral level does the esophagus pierce the diaphragm to enter the abdomen?
T9/T10
What happens to the vagal trunks associated with the esophagus in the thorax?
The left and right vagi become anterior/posterior respectively and pass through the diaphragm to supply parasympathetic innervation to the prevertebral plexuses of the abdomen.
Is there an anatomical sphincter at the gastroesophageal junction?
NOOOO
What keeps gastric reflux from normally occurring at the gastroesophageal junction?
It is a physiological sphincter, the negative pressure of the thorax keeps the esophagus pressed closed.
List organs that have an anatomical relationship with a specific aspect of the stomach.
Anterior/superior: anterior abdominal wall, left costal margin, diaphragm; Left: spleen; Right: quadrate and left lobes of the liver; Posterior: diaphragm, left suprarenal gland, upper pole of left kidney, pancreas and left colic flexure.
What divides the right and left lobes of the liver anatomically when viewed from its
anterior aspect?
The falciform ligament
What does the anatomical arrangement between the visceral peritoneum of the liver and the diaphragm form by its reflection.
It creates the bare area of the liver, left triangular ligament and right coronary ligaments.
What does the bare area of the liver come into contact with? Be specific.
The bare underside of the diaphragm.
Why is the bare area of the liver important?
Liver abcesses can pass “silently” up through the diaphragm giving little notice before perforating through into the pleural cavity.
What is the function of the gallbladder?
To store and concentrate bile secreted by the liver.
Why does the gallbladder have a serosa and an adventitia?
That portion of the gallbladder exposed to the abdominal cavity is covered with peritoneum, that portion attached to the underside of the liver has no peritoneum = adventitia.
List the 3 parts of the small intestinal, in order, from proximal to distal.
Duodenum, jejunum, ileum.
Which of these 3 regions is predominantly retroperitoneal?
The duodenum.
Which of these 3 regions are mesenterized?
Jejunum and ileum
In which direction does the root of the mesentery cross the posterior abdominal wall?
From upper left to lower right.
How can you differentiate the ileum from the jejunum?
The fat within the mesentery does not encroach upon the wall of the jejunum leaving “mesenteric windows” (except in obese individuals); in the ileum the fat comes right up to the ileal wall obliterating these windows.
What is a taeniae coli?
One of 3 longitudinal bands of smooth muscle.
What is the function of these 3 taeniae?
They “shorten” the tube, gathering it up and creating pocket-like compartments called haustra.
What is the function of a haustral compartment?
They slow down the movement of feces through the large intestine allowing water resorption to occur.
Where do the taenia coalesce into a complete outer layer of longitudinal smooth
muscle?
On the surface of the rectum as well as over the surface of the appendix.
Identify the abdominal organs considered to be retroperitoneal.
Descending aorta, duodenum, pancreas, inferior vena cava, suprarenal glands, kidneys, ureters, ascending and descending colon.
List the 4 parts of the duodenum.
1st (superior); 2nd (descending); 3rd (horizontal); and 4th (ascending).
Which portion contains the duodenal papilla?
The 2nd (descending).
What empties into the duodenal lumen at this papilla?
Bile and pancreatic enzymes.
What organ is found nestled within the C-shape concavity of the duodenum?
The head of the pancreas
What two important anatomical structures lie posterior to the 1st part of the duodenum?
Biliary duct (common bile duct) and main pancreatic duct.
Which anatomical structures pass anterior to the 3rd part of the duodenum?
The supermester mesenertic vein and artery.
Cite the anatomical relationship each of the following has with the pancreas:
duodenum, spleen, formation of the hepatic portal vein, superior mesenteric a. and
v., the splenic a., and the hilus of the spleen.
Duodenum: head of pancreas nestled in C-shaped concavity; hepatic portal vein: formed behind the neck; Superior mesenteric a. and v.: pass anterior to the uncinate process; splenic a.: often lies embedded along the superior border of the pancreas; spleen: the tail of the pancreas lies in the hilus of the spleen.
List the 3 main arterial trunks off the aorta that are responsible for supplying the G.I.T.
Celiac trunk; superior mesenteric and inferior mesenteric aa.
Which general region of the gut does each of these 3 main arteries of the aorta supply?
Celiac trunk: foregut; superior mesenteric a.: midgut; and inferior mesenteric a.: Hindgut.
What specific portions of the tubular G.I.T. are contained within each of these regions?
Foregut: lower esophagus to mid duodenum; midgut: mid duodenum to mid transverse colon; hindgut: mid transverse colon to rectum.
Know the anatomical extent of each of viscera supplied by each of these 3 aa.
Celiac trunk: lower esophagus to mid duodenum; superior mesenteric a.: mid duodenum to mid transverse colon; inferior mesenteric a.: mid transverse colon to rectum.
Where does the formation of the hepatic portal vein occur?
Posterior to the head/neck of the pancreas.
What is the function of the hepatic portal system?
To ensure that ingested materials from the G.I.T. are screened by the liver prior to release into the systemic circulation.
What is the importance of the portocaval anastomoses?
They are indicative of a blockage of either of the two circulatory systems (hepatic portal and systemic) concerned.
Name the location of at least 3 of the more clinically relevant ones.
Esophagus: esophageal varices, anal canal: hemorrhoids, and umbilicus: caput medusa.
