GI - Overview (important) Flashcards
Four key process of the digestive system ?
1) Ingestion
2 ) Digestion
3) Absorption
4) Exrection
Components of GI tract ?
GI TRACT
-Mouth
- Oral cavity
-Oesophagus
- stomach
- Small int
- Large int
- Rectum
- Anus
Accessory compontent
Teeth, Salivary glands, Pancreas, Gall bladder,Liver
What is the role of the Mucosa in GI tract ?
Surrounds innermost Lumen. Secretes mucus, Digestive enzymes + Hormones.
What is the role of Submucosa in GI tract ?
Enables PERISTALSIS ( Involuntary contraction/ relaxation that moves food along GI tract)
What prevents the back flow of food ?
Sphincter
Where and how does Digestion begin ?
Mouth - Begins with Mastication (chewing food into smaller substances 0 and Sailvary Amylase
Where does Protein digestion occur and which enzyme is involed ?
In Stomach using Pepsin (active form of Pepsinogen)
Three parts of Small int ?
Duodenum, Jejunum, ileum
Function of Bile ? =
Emulsifies fats, & Aids in absorption of Fat soluble vitamins (A,D,K)
Primary site of nutrient absorption ?
Small intestine (Jejunum)
What are the three digestive phases ?
Cephalic - Triggered by sight, smell, thought of food. Gastric secretions stimulated by CNS to prepare for food by producing saliva
Gastric Phase: when food reaches stomach, leading to secretion of gastric juices & increased stomach motility to further digest the food
Intestinal phase : Starts as partially digested food enters the small intestine; regulates further digestion and nutrient absorption.
What is role of Large intestine in digestion ?
Absorption of Water,Electrolytes
Function of mucus secreted by GI tract ?
Traps pathogens, neutralizes acid + protects mucosal lining
Role of pancreas in Digestive system ?
Produces digestive enzymes that aid in breakdown of fats, proteins + carbohydrates. Also secretes bicarbonate to neutralize stomach acid in small intestine.
Role of liver in digsetive system ?
Production of bile - Essential for digestion + absorption of fats
