Small and Large Intestine

Oropharynx and Esophageal Pathology

GI Embryo

GI Embryo

GI Physiology

Upper GI
Stomach
Liver + Gallbladder
Pancreas

Here are my notes. I used lectures from class, Boards and Beyond, some youtube. Hope it helps!

GI Blood Supply

Perforated Ulcers
Ulcers on the lesser curvature of the stomach can cause bleeding from the left gastric artery.
Posterior duodenal ulcers can cause bleeding from the gastroduodenal artery.

Short Gastric Arteries
The short gastric arteries are branches off the splenic artery. They supply the fundus. Unlike other arteries of the stomach, the fundus does not have dual blood supply. Thus it is more vulnerable to ischemia.

Pringle's Maneuver 
During an abdominal surgery, you can clamp down on the hepatoduodenal ligament to see if the bleeding stops. If it does, the bleed was from the proper hepatic artery or the portal vein. That's because the hepatoduodenal ligament contains the proper hepatic artery, portal vein, and cystic duct. If the bleeding continues, the bleed is from somewhere else (like the IVC).

SMA Syndrome
The superior mesenteric artery courses over the duodenum. Usually mesenteric fat provides padding, but if there isn't enough fat, the artery can be compresses. This leads to bowel obstruction.

Dual Blood Supply
stomach - celiac trunk and superior mesenteric artery (superior and inferior pancreaticoduodenal arteries)
transverse and descending colon - superior and inferior mesenteric (marginal artery of Drummond)
rectum - inferior mesenteric artery and iliac artery (superior rectal and middle rectal)

Mesenteric Ischemia
-small intestine
-embolism and arterial thrombosis
-venous thrombosis
-under perfusion from shock (affects watershed areas of colon which include splenic flexure and rectosigmoid junction)
-intestinal angina (fear of eating)
-increased WBC, lactate, acidosis
-occult blood in stool

Ischemic Colitis 
-colon

Brachial Plexus

Just a quick explanation in case it's not clear on the image. I also recommend going through the motions with your hand. It helps! :3

Distal lesions will affect the lumbricals, so the fingers cannot extend.
Proximal lesions will affect the flexors, so the hand cannot make a fist.

A distal lesion of the ulnar nerve will cause the patient to have difficulty uncurling the 4th and 5th digit, but the 2nd and 3rd digit can. A proximal lesion to the medial nerve will cause the patient to have difficulty curling the 2nd and 3rd digit, but the 4th and 5th can. Both will end up looking like the Pope blessing.

A proximal lesion to the ulnar nerve will cause the patient to have difficulty curling the last two digits while a distal lesion to the median nerve will cause the patient difficulty uncurling the 2nd and 3rd digit. Both will end up looking like the OK gesture.

Review Questions

A patient presents to his PCP with a 3 day history of fever, chest pain, and cough. He informs you that he recently went on a trip exploring caves in the midwest. The chronic form of this condition will lead to granulomas and cavitations in the upper lobes of the lungs. What do you expect to find upon histology?
A) pilot's wheel shaped fungus
B) thick walled cells showing broad based budding
C) acid fast bacteria
D) macrophages filled with many yeast-like cells
E) pleural cells showing a biphasic pattern (epithelioid cells and sarcomatoid cells)

A 50yo female with a history of asthma presents to the clinic complaining of white spots in her mouth. She explains that the spots started appearing ever since she started using Fluticasone. She is worried that this may be cancer, but you find that the spots can be scraped off. What does this organism do at 37 degrees Celsius?
A) forms yeast cells
B) unable to grow
C) cause pseudomembranes in the colon
D) leads to changes in vaginal pH
E) forms germ tubes

A 15yo male presents to the clinic with dyspnea. His IgE levels are elevated and CXR reveals bilateral migrating infiltrates. If we were to examine the organism under microscope, we'd see V-shaped branching. The patient has a condition that predisposes him to this condition. What mutation causes this condition?
A) VHL gene chromosome 3
B) COL4A5 gene X chromosome
C) CTFR gene chromosome 7
D) SERPINA1 gene chromosome 14
E) WT1 gene chromosome 11