GI 1 Flashcards
Healthy balanced diet portions are:
1/2 carbs
1/4 protein
1/4 grains
Function of the digestive system:
-Break down foods to release their nutrients
-Absorb into body
The Gastrointestinal Tract includes:
1- Organs of the alimentary canal
2- Accessory glandular tissues
Alimentary Canal
A muscular tube made of DIFFERENT ORGANS with coordinated activity to move food UNIDIRECTIONALLY from mouth to anus
What are the 7 parts (organs) of the alimentary canal?
1- Mouth
2- Pharynx
3- Esophagus
4- Stomach
5- Small Intestine
6- Large Intestine
7-Anus
Exocrine Organs (aka accessory glandular tissues?)
Lie outside the digestive tract and empty their secretions through ducts into the digestive tract lumen
What are the 5 exocrine organs?
1- Salivary Glands
2- Exocrine pancreas
3- Billary system
4- Liver
5- Gallbladder
The 4 tissues lining alimentary canal
1-Mucosa
2-Submucosa
3-Muscularis
4-Serosa
Mucosa:
An epithelial cell layer directly in contact with food/chyme .:. separating the food from the inner environment of the body
**
In the esophagus: squamous cell layer to move food quickly
In the stomach: columnar cell layer to make pits to secrete acid
In the small intestine: also columnar with villi to helo increase SA for absorption
Submucosa
A connective tissue layer anchor epithelia to the rest of the alimentary canal
Muscularis mucosae
Smooth muscle that contracts the mucosa epithelial layer
Serosa
Another layer of connective tissue anchoring GI tract to other organs of the body
ًwhat from the external environment is the alimentary canal a barrier against?
-Acidic pH of the stomach
-The digestive enzymes (could destroy body’s tissues)
-Gut flora
GI tract barrier formed through: (2 things)
-Tight junctions (between epithelial cells in the mucosa layer)
-Mucus* (and other secretions produced by mucosa)
*alkaline to neutralize acid and prevent physical damage
4 main GI functions:
Secretion
Motility
Digestions
Absorption
