GI/Liver Flashcards
Type of cells lining the esophagus
Stratified squamous cells. This type of epithelium is well suited to areas of the body subjected to constant abrasion, such as the mouth, esophagus, and vagina. Your mom, for example, has a thick layer of stratified squamous epithelium.
The fluid leaving the stomach must have the same ________ as blood
Tonicity
Once fluid enters the small intestine, the pH need to be raised from _______ to about _____.
1.5 to 8
Area of the GI tract where B and T cells might hang around to find their antigen
Appendix
Nutrients absorbed in the stomach
Water and alcohol
Nutrients absorbed by the duodenum
Water Fats Sugars Proteins Vitamins Calcium Sodium Mag Iron
Nutrients absorbed by the Jejunum
Sugars and proteins. Most absorption occurs in the jejunum.
Nutrients absorbed by the ileum
B12
Bile Salts
Chloride
Nutrients absorbed by the large intestine
Water and electrolytes
Barrett’s Esophagus involves replacing this type of tissue with this type of tissue
Stratified squamous with metaplastic columnar epithelium with goblet cells (which secrete mucus)
Barrett’s esophagus can lead to
Adenocarcinoma, which is cancer of the epithelium.
Types of esophageal cancer
1) Squamous cell
- Arises from normal esophageal tissue
- Caused by tobacco/ETOH, achalasia (from increased irritation and mitotic turnover), and very hot tea (>65C)
2) Adenocarcinoma
- Arises of metaplastic tissue associated with Barrett’s Esophagus
Symptoms of esophageal cancer
Obstruction leading to dysphagia
However, this occurs late in cancer progression.
Chronic gastritis can lead to
Peptic ulcers
Acute gastritis can lead to
Acute gastric ulceration
Layers of muscle in the stomach
Longitudinal, circular, and oblique
Purposes of the duodenum
Raises the pH of chyme and controls the rate of gastric emptying. It also absorbs a bunch of shit.
Chief cells produce ______
Parietal cells produce _____
Chief = the enzymes of gastric juice Parietal = stomach acid
How do we deal with the excess bicarb production as a result of acid production?
The bicarb generated gets dumped into the lumen of the duodenum, preventing the blood from becoming alkalotic and raising the pH of chyme in the duodenum.
Why are NSAIDs damaging to the stomach?
The inhibit prostaglandins, which normally stimulate the production of mucus. Decreased mucus production subjects the gastric mucosa to damage.
Basic difference between acute and chronic gastritis
Chronic gastritis is due to an H. pylori infection or chronic NSAID use. It is usually asymptomatic, but may cause upper abdominal discomfort, N/V, and peptic ulcers.
Acute gastritis is general injury to the body (not specifically the stomach), such as heavy NSAID use, smoking, ETOH, chemo, systemic infection, severe stress, etc. This can cause epigastric pain with N/V, and hematemesis and/or melena.
Treatment for acute gastritis
Remove the cause of stress to the body
__-__% of people with H pylori get ulcers, but H pylori is present in ___% of those with gastric and duodenal ulcers
10-20%
70%
These things can aggravate peptic ulcers
NSAIDS Smoking ETOH Corticosteroids High-stress personality
Treatment for peptic ulcer
We can give antibiotics because most cases are caused by H pylori
Complications of peptic ulcers
Epigastric pain
N/V
Perforation and hemorrhage
Do peptic ulcers progress to cancer?
No.
Causes of acute gastritis
Acute mucosal inflammation due to systemic things like: Heavy NSAID use (like ASA) Excessive ETOH Heavy smoking Chemo Uremia Systemic infection Severe stress (trauma, burns, surgery) Ischemia and shock Ingestion of caustic agents Mechanical trauma (nasogastric tube placement)
S/S of acute gastritic
The same as chronic gastritis.
Epigastric pain, N/V, hematemesis and/or melena
Treatment for acute gastric ulcer (stress ulcer)
Remove the cause of stress to the body
2 Types of stomach cancer
1) Intestinal Adenocarcinoma (decreased in frequency)
- Caused by nitrates, smoked food, pickled/salted food, low fruit and veggie consumption, chronic gastritis, and H pylori
2) Diffuse carcinoma
- Risk factors poorly understood
- Incidence hasn’t decreased, but was never very prominent anyway
It takes ___ hours to get from the mouth to the cecum, and ___ hours to get from the cecum to the anum
2-4
20-22
Causes of ischemic bowel disease
Arterial or venous thromboembolism
Non-occlusive ischemia (shock, dehydration, vasoactive drugs)
Mechanical obstruction (volvulus, stricture, herniation, etc
Complications of ischemic bowel disease
Mild infarction ok because it may only kill mucosal cells, which we replace frequently.
Major transmural infarction causes wall weakness that can lead to rupture, sepsis, and peritonitis. 90% mortality.
Common causes of hemorrhoids
Straining on defecation
Portal HTN
Pregnancy (pressure on IVC shunts blood to the portal system)
Caused by increase venous pressure in the hemorrhoidal plexus.