Topic 9 Gastrointestinal system Flashcards
The organs and collectively perform digestion and absorption
Gastrointestinal system
The breaking down of food into molecules small enough to be absorbed
Digestion
The passage of molecules through the plasma membranes of the cells lining the stomach and intestines into the blood and lymph
Absorption
2 structures of the Gastrointestinal system?
1) Gastrointestinal tract
2) Accessory digestive organs (organs that contribute to process)
The continuous tube from the mouth to the anus
Gastrointestinal tract
aka alimentary canal
Name the accessory digestive organs - GI system (6)
Teeth Tongue Salivary glands Liver Gallbladder pancreas
Name the functions of the Gastrointestinal system (6)
1) ingestion
2) secretion
3) mixing and propulsion (slow movement)
4) digestion
5) absorption
6) elimination
Function - eating
Ingestion
Function - cells in the walls of of the GI tract and accessory organs secrete water, acid, buffers (nutralize enzyme) and enzymes into the lumen (inner portion of GI tract) of the tract
Secretion
Function - muscles in the organ wall rhythmically contract and relax to mix food and secretions together and to move the mixture through the system
Mixing and propulsion
Function - 2 types
1) mechanical - breaking down food
2) chemical - substances to break down food
Digestion
type of digestion
> Tongue mixes food
> teeth grind and cut food
> stomach and small intestine churn/ mix food
Mechanical digestion
type of digestion
> enzymes help break larger nutrients into smaller ones (which can be absorbed)
> enzymes are secreted by salivary glands, tongue, stomach, pancreas, small intestine
Chemical digestion
Function - 3 types…
> taken in through the membranes of cells lining the stomach and small intestine
> enters the blood or lymphatic systems
> circulated throughout the body
Absorption
Function - AKA defecation
Elimination
