Ch.23-2 Digestive System Flashcards
What are the two major categories of digestive system organs?
1) Alimentary Canal/Gastrointestinal Tract (GI) 2) Accessory Digestive Organs
List the organs that make up the Alimentary Canal.
- Mouth * Pharynx * Esophagus * Stomach * Large intestine * Small intestine * Anus
What is the primary function of the stomach?
Temporary storage tank where chemical breakdown of proteins begins and food is converted into chyme
Which enzymes and acids are involved in protein digestion in the stomach?
- HCl * Pepsin * Rennin
What is the essential function of the stomach related to vitamin absorption?
Secretion of intrinsic factor, which helps absorption of vitamin B12
What are the three stages of gastric activity associated with eating?
- Cephalic phase * Gastric phase * Intestinal phase
What triggers the cephalic phase of gastric secretion?
Taste, smell, sight, and thought of food
During which phase does gastrin play the greatest role in stimulating stomach gland secretion?
Gastric phase
What is the primary effect of highly acidic gastric contents on gastrin secretion?
Inhibits gastrin secretion
What is the enterogastric reflex?
A trio of reflexes that inhibit gastric activity when the intestine fills
How does the pylorus function in gastric emptying?
Acts as a filter, permitting only liquids and small food particles to pass
What is the typical time frame for the stomach to empty after a meal?
About 4 hours
What is segmentation in the context of the small intestine?
Main means of moving food, involving kneading back and forth by contraction/relaxation of smooth muscle rings
What role does the liver play in digestion?
Produces bile that emulsifies fats for easier digestion
What are the primary functions of the liver?
- Metabolism of fats, proteins, and carbohydrates * Storage of glycogen, vitamins, and minerals * Synthesis of plasma proteins * Excretion of bilirubin, cholesterol, hormones, and drugs
What is the structure that carries bile from the liver?
Common hepatic duct
What is the functional unit of the liver?
Lobules
What is found in the portal triad of liver lobules?
- Hepatic artery branch * Hepatic portal vein * Bile duct
What is the role of bile salts?
Help emulsify fats by breaking them into smaller pieces
What does the gallbladder do?
Stores and concentrates bile from the liver
Fill in the blank: The small intestine extends from the _______ to the ileocecal valve.
Pyloric sphincter
What are the subdivisions of the small intestine?
- Duodenum * Jejunum * Ileum
What is the primary function of the jejunum?
Absorbs most nutrients from digested food
What is the function of microvilli in the small intestine?
Increase the surface area for absorption and contain brush border enzymes
What is the daily production of intestinal juice?
About 1.5 L
What is the role of Peyer’s patches?
Help remove bacteria to prevent entry into the bloodstream
