Digestive 3 Flashcards
How is mucus produced and what is its role?
Produced by surface mucous cells and mucous neck cells.
Vital for maintenance of a protective barrier against self digestion of the stomach walls.
What causes ulcers?
Most caused by bacterial infection.
What are the role of chief cells in the stomach?
Secrete pepsinogen (pepsin, breaks down proteins into peptides) and gastric lipase.
Role of parietal cells in stomach?
Secrete hydrochloric acid (kills microbes in food) and intrinsic factor (vitamin b absorption)
List the 3 sections and role of the small intestine.
The major events of digestion and absorption occur in the SI.
Duodenum
Jejunum
Ileum
Role of pancreas
Produces important hormones
(Insulin, glucagon, somatostatin,etc)
Also is a digestive organ secreting pancreatic juice containing digestive enzymes.
Explain pancreatic juice
Contains sodium bicarbonate that neutralizes stomach acid and inactivates pepsin.
Digests starch, proteins, fats and nucleic acids.
Secreted by pancreas
Is alkaline and useful for neutralizing the acidic gastric acid
List properties of bile
Part extretory, part secretion
Made up of water, cholesterol, bile salts and bile pigments.
Liver functions
Store some triglycerides Break down fatty acids Synthesize cholesterol Excretes waste product (bilirubin) Releases bile salts for digestion Processes hormones
Describe how and where carbs are digested and absorbed
Broken down along GI tract
Starches and sugars
Amylase breaks apart starches in the mouth and small intestine
Sucrase, maltase and lactase break apart sugars. Also found in mouth and small intestine
Why is it necessary for the stomach to be so acidic?
Pepsin works best in an acidic enviroment to begin the breakdown of protein.
Also helps to kill some bacteria in food
