Pathology of the General Intestinal Tract Flashcards
This GI pathology is caused by the twisting of a loop of the bowel around its mesenteric base of attachment.
Volvulus
What is the most common cause of ischemic colitis?
Arterial obstruction
Acute appendicitis is a surgical emergency with pain in the RLQ. At what point does pain often localize?
McBurney’s Point - 1/3 of the way from the ASIS to the umbilicus
Diverticulosis pain generally arises in what quadrant?
LLQ - descending and sigmoid colon
What are diverticula?
Small outpouchings or sacs in the GI wall through the lamina propria
True/False. Patients with ischemic colitis may present with severe abdominal pain, but a normal abdominal exam.
True - this is called pain out of proportion to exam
This pathology is due to malformed mucosal and submucosal blood vessels, most common in the sixth decade.
Angiodysplasia
Tyeps of ischemic infarcts.
Mucosal and mural infarcts have a better prognosis than transmural that involves more layers.
What is the most common clinical symptoms of angiodysplasia?
Hematochezia - undigested blood in stool
Mesenteric venous thrombosis is classically a result of Virchow’s triad that causes ischemic colitis. What is Virchow’s triad?
Stagnant blood flow, hypercoagulability, vascular injury
Where do direct hernias originate?
Direct hernias are acquired, originate medially to the inferior epigastric artery, and protrude through the inferior peritoneal ring
This type of hernia can be manually reduced back into the abdominal cavity with a finger or by lying supine.
Reproducible hernia
These two factors are responsible for hernia formation.
Weakness of the peritoneal wall and increased abdominal pressure
What areas are most commonly affected by angiodysplasia?
Right colon and cecum
How do the causes of intussusception in children and adults differ?
Most cases occur in children and are idiopathic. In adults, intussusception is often caused by an intraluminal mass.
Watershed areas are the most susceptible to ischemic damage. Where are these areas?
Splenic flexure and rectosigmoid junction
This type of hernia is difficult or impossible to retract due to the enlargement of the hernial sac by obstructed venous flow.
Incarcerated hernia
What is the bloody supply for the distal transverse colon and descending colon?
Inferior mesenteric artery
Blood may appear in the stool in cases of ischemic colitis. Why is this?
Surface epithelium dies due to poor blood flow and ischemia. The dead epithelium sloughs off and carries blood with it in the stool.
Where do cecal volvulus arise?
RLQ - cause collapse of the ascending, transverse, and descending colon
This condition is caused by a lack of blood flow to the bowel, that may be obstructive or non-obstructive.
Ischemic colitis
This type of volvulus arises in the LLQ and is characterized by the coffee bean sign on imaging.
Sigmoid volvulus
How do true and false diverticula differ?
True diverticula involve all layers. False diverticula only involves the mucosal and submucosal layers.
What is the number one cause of small bowel obstructions?
Adhesions
