Gastrointestinal Flashcards
(60 cards)
What is the starting point of digestion?
Mouth
Digestion starts in the mouth with mechanical and chemical processes.
What is the role of salivary amylase in digestion?
Breakdown starches to maltose
Salivary amylase (ptyalin) initiates chemical digestion in the mouth.
What is deglutition?
Swallowing
Deglutition occurs once food is formed into a bolus and mixed with saliva.
What is the function of the esophagus?
Passage for food bolus from mouth to stomach by peristalsis
The esophagus transports food using coordinated muscle contractions.
What prevents gastric reflux?
Lower esophageal sphincter (LES)
Also known as the cardiac sphincter, it guards the distal end of the esophagus.
What is the capacity of the stomach?
Approximately 1,500 mls
The stomach is located in the left upper quadrant of the abdomen.
List the regions of the stomach.
- Cardiac region
- Fundus
- Body
- Antrum (pyloric region)
These regions serve different functions in digestion.
What is the primary function of gastric juice?
Digestion of proteins and protection against bacteria
Gastric juice is composed of mucus, HCl, pepsinogen, and water.
What is pepsinogen?
Inactive enzyme converted to pepsin in the presence of HCl
Pepsin begins protein digestion in the stomach.
What happens to carbohydrates in the stomach?
Digestion stops due to inactivation of amylase by acidity
The acidic environment halts carbohydrate digestion initiated in the mouth.
What is the length of the small intestine?
About 6 meters (20-22 ft)
It extends from the pyloric sphincter to the ileocecal valve.
What are the three parts of the small intestine?
- Duodenum
- Jejunum
- Ileum
The majority of digestion occurs in the duodenum.
What hormones do endocrine cells in the small intestine secrete?
- Cholecystokinin
- Secretin
- Enterogastrone
These hormones regulate bile and pancreatic juice secretion.
What is the main function of bile?
Emulsifies fats
Bile facilitates the action of pancreatic lipase on dietary fats.
What are the primary functions of the large intestine?
- Absorption of water, Na, and Cl
- Vitamin synthesis
- Formation of feces
- Defecation
Approximately 800-1000 mls of water is absorbed here.
What is the normal range for Body Mass Index (BMI)?
18.5 – 24.9
BMI is a measure of body fat based on height and weight.
What does a (+) CEA indicate?
Colorectal cancer
CEA (Carcinoembryonic Antigen) is a tumor marker used in diagnosis.
What is the purpose of the D-Xylose Absorption Test?
Diagnosis of malabsorption
It measures the absorption of D-Xylose in blood and urine.
What dietary restrictions are required before a fecal occult blood test?
- No red meats
- No poultry
- No fish
- No turnips, horseradish, cauliflower, broccoli, melon
These foods may cause false positives in the test results.
What is the Bernstein Test used for?
To assess if chest pain is related to gastro-esophageal reflux
It involves instilling normal saline and HCl into the esophagus.
What imaging technique uses a contrast medium to visualize the upper GI tract?
Upper GI Series (Barium Swallow)
Barium sulfate is administered to visualize esophagus, stomach, and duodenum.
What is the primary purpose of endoscopy?
Direct visualization of the upper GI tract
It includes examination of the esophagus, stomach, and duodenum.
What is the significance of the vermiform appendix?
Attached to the cecum
It is part of the large intestine, but its exact function is still debated.
What is Computed Tomography?
Uses beam of radiation to assess cross sections of the body
