GI 1 Flashcards
GI tract: purpose
- food digestion
- absorption of nutrients and water
Primary disorders of the GI tract are related to:
- damage from gastric acid secretion
- abn food movement through GI tract
Components of GI tract
- mouth
- esophagus
- stomach
- small intestine
- large intestine
Components of large intestine
- colon
- rectum
- anus
This can function completely independently from the CNS and is known as the “brain in the bowel”
enteric nervous system
Why is the enteric nervous system the focus of a lot of research?
There are as many neurons in the small intestine as the spinal cord
Gut and immunity
gut contains 70-80% of the body’s immune cells
Intestinal layers: inside to outside
- mucosa
- submucosa
- muscularis
- serosa or adventitia
How many esophageal sphincters?
2
What are the esophageal sphincters
- upper
- lower
The lower esophageal sphincter is sometimes called the ______ sphincter
cardiac
Voluntary control of esophageal sphincters
Have control over upper, but not lower
What are the gastric secretions?
- acid
- enzymes (pepsin)
- mucus
- hormones (gastrin)
This helps to activate pepsin
hydrochloric acid
What does acid inactivate?
ingested microorganisms (bacteria)
What are enzymes (pepsin) responsible for
Largely responsible for stomach’s ability to initiate digestion of PROTEINS
What does mucus do?
- coats and lubricates the gastric surface
- very abundant
Hormones (gastrin): What does this do?
- assists with gastric mobility
- also further stimulates acid and pepsin secretion
Where is gastrin secreted?
lower part of the stomach
What are the 3 phases of gastric secretions?
- cephalic
- gastric
- intestinal
