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
How is achalasia different from obstruction?
Achalasia is dysphagia of solids and liquids while obstruction is just dysphagia of solids
What test can we use to check for achalasia and what will it show?
Barium swallow shows dilated esophagus with an area of distal stenosis - “Bird’s beak”
Achalasia is associated with an increased risk of what cancer?
Esophageal squamous cell carcinoma
Achalasia maybe be secondary to what other disease?
Chagas
What is Boerhaave syndrome?
Transmural, usually distal esophageal rupture due to violent retching
How should Boerhaave syndrome be treated?
Surgical emergency
What is eosinophilic esophagitis?
Infiltration of eosinophils in the esophagus in atopic patients (food allergy)
What are 3 characteristics of eosinophilic esophagitis?
Dysphagia, heartburn, strictures
Can eosinophilic esophagitis be treated with GERD therapy?
No
Characterize esophageal varices.
Painless bleeding of dilated submucosal veins in the lower 1/3 of esophagus
What are esophageal varices secondary to?
Portal hypertension
What are 3 associations of esophagitis?
- Reflux
- Infection in immunocompromised
- Chemical ingestion
What are 3 infections that are associated with esophagitis and how do you differentiate between them?
- Candida - white pseudomembrane
- HSV-1 - punched out ulcers
- CMV - linear ulcers
How does GERD typically present?
Heartburn, regurgitation upon lying down, nocturnal cough and dyspnea, adult-onset asthma
GERD involves decreased tone of which sphincter?
LES
What is Mallory-Weiss syndrome?
Mucosal lacerations at the GE junction due to severe vomiting
What is a key presenting symptom of Mallory-Weiss syndrome?
Hematemesis
What 2 groups are especially prone to Mallory-Weiss syndrome?
Bulimics and alcoholics
What is the triad of Plummer-Vinson syndrome?
Mnemonic: DIG
Dysphagia (due to esophageal webs), Iron deficiency anemia, Glossitis
Describe the pathophysiology of sclerodermal esophageal dysmotility.
Esophageal smooth muscle atrophy leads to decreased LES pressure and dysmotility leads to acid reflux and dysphagia leads to stricture, Barrett esophagus, and aspiration
What syndrome is sclerodermal esophageal dysmotility a part of?
CREST
What is Barrett esophagus?
Glandular metaplasia - replacement of nonkeratinized (stratifeid) squamous epithelium with intestinal epithelium (nonciliated columnar with goblet cells) in the distal esophagus
What causes Barrett esophagus?
Chronic GERD