GI: 349 - 353 Flashcards
Bilirubin is a product of the metabolism of what?
Heme
What is another name for unconjugated bilirubin?
Indirect
Direct vs. indirect bilirubin - which one is water soluble?
Conjugated - water soluble; Unconjugated - water insoluble
What is bilirubin conjugated with to make it water soluble?
Glucuronic acid
What organ removes bilirubin from the blood?
Liver
Where is heme broken down into bilirubin?
Macrophages
How does bilirubin get to the liver?
Travels in the bloodstream bound to albumin
Where does bilirubin get conjugated?
Liver
What enzyme conjugates bilirubin?
UDP-glucuronosyl-transferase
Where does conjugated bilirubin go and what does it become?
To the gut where it becomes urobilinogen
80% of urobilinogen does what?
Excreted into the feces as stercobilin which gives feces its brown color
20% of urobilinogen does what (2 possible fates)?
- 90% (of this 20%) reenters enterohepatic circulation and goes back to the liver.
- 10% (of this 20%) is excreted in urine which gives urine its yellow color
Are salivary gland tumors generallly benign or malignant?
Benign
Which salivary gland is most likely to have a tumor?
Parotid gland
What are 3 types of salivary gland tumors?
- Pleomorphic adenoma
- Warthrin tumor
- Mucoepidermoid carcinoma
Which is the most common salivary gland tumor?
Pleomorphic adenoma
What is a pleomorphic adenoma composed of?
Benign mixed tumor - made of chondromyxoid stroma and epithelium
How does pleomorphic adenoma present?
Painless mobile mass
When does pleomorphic adenoma recur?
Incomplete excision or intraoperative rupture
Describe a warthrin tumor.
Papillary cystadenoma lymphomatosum - a benign cystic tumor with germinal centers
What is the most common malignant salivary gland tumor?
Mucoepidermoid carcinoma
Describe a mucoepidermoid carcinoma
Has mucinous and squamous components that typically presents as a painless slow-growing mass
What is achalasia?
Failure of relaxation of LES due to loss of myenteric (Auerbach) plexus
What happens in achalasia?
High LES opening pressure and uncoordinated peristalsis leads to progressive dysphagia to solids and liquids