Lecture 2 Flashcards
What is this lecture about?
Ischemic bowl diseases
What are the causes of IGI bleeding?
- peptic ulcers
- Inflammatory bowel disease (IBD)
- Carcinoma
- ischemic bowl
- hemmorids
How to differentiate between ischemic bowl and normal bowl in histology? What can cause them.
- You can see villus in normal bowls
- No architecture and structure in ischemic bowl, its hyperchromatic and you see a lot of eosinophils and blood
- Caused by small emboli you can see blocking vessels
- villi losing shape
Gross appearance is dusky or hemorrhagic if its infarcted
What causes pesudomembranes of the GI Tract? Where is it not seen?
- Ischemia
- Infections
- -Shigella, candida and C. Difficile
Not Seen in
-ulcers, IBD, carcinoma an Hemmorids
What are the causes of bowl ischemia?
-emboli
-Thrmobosis
Generalized poor perfusion-shock or or carida
-Twisted bowl and hernias
What makes bowl ischemia worse?
-Splanchnic diving, meaning less blood flow to bowl to save brain, kidneys and heart
How does ischemia progess? What are the dangers?
it will turn into transmural infarction, mural and mucosal infarction and chronic ischemia
Death of muscularis propria and the epithelium or mucosa dies first
What are the signs of Ischemic bowl?
- Cramps, pain and spasm
- Chronic wil have intestinal angina aftermeals
- Nausea, vomitting and melena
- tenderness
What is the lab results and complication of ischemic bowl?
-Increased WBC
-Complications
GI Bleeding, sepsis, periotinitis and perforation
What causes sepsis?
When body is overwhelmed with an immune response against antigen
-This leads to chmical mediators that end up damaging the epithelium and causes blood clots and thrombi
What is the mechanism of sepsis?
LPS form g- bacterial wall binds to LPS binding protien this trigers inflammatory cells.
-Macrophages relasese TNF and IL-1 this induces tissue facror and activates neutrophils leadint to tissue damage
What do TNF and IL-1 do? Whats the cytokine cascade lead to?
- TNF and IL-1 induce thromblastin, upregulates adhesion molecules leading to PMNs attachment and endothelial damage
- the cytokine cascade leads to NO release leading to vasodialtion, Hypotension adn then shock,
What are the complications with the lung?
Neutrophil macroaggregates promote pulmonary thrombosis leading to ARDS. Septic shock can lead to multi organ failure
What is the treatment of ischemic bowel disease?
Antibiotics ( to stop sepsis)
- Correct underlying conidtion for example hypotension
- Surgery to remove necrotic bowel
