GI Flashcards
Most common location of salivary gland tumors:
Parotid gland
Most common salivary gland tumor:
Second most common:
Pleomorphic adenoma
Warthin’s tumor
Most common malignant salivary gland tumor:
Mucoepidermoid carcinoma
This very common genetic defect is a risk for duodenal atresia:
Trisomy 21
Jejunal, ileal, and colonic atresia are due to this event during fetal development. What about duodenal atresia?
Duodenal = failure to recanalize
Jejunal et c = vascular accident
This anterior abdominal wall defect can contain a herniated liver, whereas this does not.
Omphalocele can have the liver protruding
Gastroschisis does not
These structures are retroperitoneal (9):
A DUCK PEAR: Adrenals Duodenoum Ureters Colon (descending and ascending) Kidneys Pancreas (except tail) Esophagus Aorta / IVC Rectum
Three metabolic abnormalities that may be seen in an infant with pyloric stenosis:
Hypochloremia
Metabolic alkalosis
Hypokalemia (K+ shift into cells to allow H+ out into blood)
Pale clay colored stool, tea urine, jaundice in the first weeks of life:
Extrahepatic biliary stenosis, failure of the bile ducts to completely re-canalize.
The pancreas is derived from this embryonic structure:
Foregut
Which pancreatic bud contributes to the head and main pancreatic duct?
Ventral bud
How does an annular pancreas happen?
Ventral bud is in two pieces
Dorsal / ventral fuse abnormally and encircle the duodenum.
Where does the spleen come from? From what tissue layer is it derived?
The stomach mesentary, it’s mesodermal.
What structures come from the hepatic diverticulum off the ventral foregut?
Liver
Gall bladder / biliary tree
Ventral pancreatic bud
Which pancreatic bud travels to meet the other bud?
Ventral swings around dorsally to join the dorsal pancreatic bud.
This embryonic structure gives rise to the body, tail, and isthmus of the pancreas:
Dorsal pancreatic bud
This ligament contains the portal triad:
Hepatoduodenal
Access to the lesser sac through this ligament:
Gastrohepatic
The tail of the pancreas is embedded in this ligament:
Splenorenal
The gastric arteries are in this ligament:
Gastrohepatic
This ligament is the remnant of the fetal umbilical vein:
Ligamentum teres hepatis
What are the layers of the gut wall (inside out) (4)?
Mucosa
Submucosa
Muscularis externa
Serosa / adventitia
This type of injury extends into the submucosa:
Ulceration
Where is the myenteric nerve plexus? What is its other name?
Myenteric = Auerbach’s
It is the OUTERbach’s plexus
This nerve plexus is the inner nerve plexus and is located in the _________.
Submucosal nerve plexus is the inner one, aka Meissner’s, it’s in the submucosa, of course.
Three arteries to the GI structures come off the aorta anteriorly:
Celiac
Superior mesenteric
Inferior mesenteric
What is SMA syndrome?
The duodenum gets caught between the SMA and the aorta and is obstructed.
Parasympathetic innervation for the:
Foregut
Midgut
Hindgut
Foregut and midgut = vagus
Hindgut = pelvic
The artery that supplies the foregut:
Celiac
The three main branches off the celiac trunk:
Common hepatic
Splenic
Left gastric
The common hepatic artery gives rise to three arteries, what are they?
Gastroduodenal
Right gastric
Hepatic artery proper
This artery gives rise to the main arteries to the pancreas:
Gastroduodenal via the anterior superior pancreaticoduodenal arteries
The R gastroepiploic artery comes from this origin, and the left comes from a separate vessel:
R from the gastroduodenal (off common hepatic)
L from the splenic (off celiac trunk)
Which zone in the liver is affected first by viral hepatitis?
Zone 1 = zone closest to the portal triad
Zone III is located near what structure in the liver?
Pericentral / centrilobular veins
What direction does bile flow relative to the central hepatic vein?
Away from it, toward the triad.
This hormone causes gall-bladder contraction:
CCK
What is the most common kind of stomach hernia? The most dangerous?
Sliding hiatal = most common
Paraesophageal = most dangerous, fundus can get trapped in this one.
Where do an indirect and a direct inguinal hernia lie relative to the inferior epigastric artery?
Indirect = lateral Direct = medial
Gastrin comes from these cells:
G cells
Pro-duodenal hormone:
CCK
This hormone is anti-gastrin
These two hormones are the main off-switch for gastric acid secretion:
CCK
Secretin
Somatostatin
Where is secretin made?
S cells in the duodenum
This hormone is the anti-hormone-hormone:
Somatostatin
This hormone hits parasympathetic ganglia in the gut:
VIP = vasoactive intestinal peptide
This substance helps relax the LES:
NO
This hormone is seriously elevated in Zollinger-Ellison syndrome:
Gastrin
Three common substances that are potent stimulators of gastrin:
Calcium
Phenylalanine
Tryptophan
Three histologic / gross / lab findings in a stomach of someone with ZE syndrome:
Thick rugae
High gastrin
Glandular hyperplasia
Cells that make IF:
Parietal cells
These glands in the duodenal submucosa secrete alkaline mucus:
When might they be hypertrophied?
Brunner’s
Peptic ulcer disease
Gastrin increases acid secretion indirectly. Briefly explain how this happens:
Gastrin hits ECL cells in the gut, which release histamine; it is histamine that hits parietal cells and tells them to secrete acid.
Type of receptor on parietal cells most important for stimulating acid secretion:
H2
Two Gi coupled receptors on a parietal cell:
Prostoglandin
Somatostatin
Both inhibit acid secretion
The H2 receptor on a parietal cell works through what second messenger?
cAMP
Two hormones stimulate pancreatic secretions:
CCK
Secretin
Where are oligosaccharide hydrolases located?
At the brush border of the intestines.
What is the rate-limiting step in carbohydrate digestion?
Monosaccharide production by oligosaccharide hydrolases
This sugar transporter sends both glucose and fructose from an enterocyte into the blood:
GLUT2
Glucose and galactose enter an enterocyte on this transporter:
What kind of carrier is it?
SGLT-1
Na-dependent
How is fructose taken into an enterocyte?
Facilitated diffusion through GLUT-5
What is the plasma carrier protein for vitamin B12?
Transcobalamin
Where are each of the following vitamins absorbed? Iron, Folate, B12:
Iron: Duodenum
Folate: Jejunum
B12: Terminal ileum, needs IF
The cells in Peyer’s patches that take up antigen:
M cells