Functional Organization and Principles of GI tract Flashcards
functions of GI tract
1) digestion and absorption of food
2) Excretion of waste materials: faeces
3) fluid and electrolyte balance :
1 kg of food and 1.5 lit of water
+ 7 lit of fluid secretions from exocrine glands
= 8.5 lit of fluid per day to the intestine
- about 99% of this fluid and 90% of solids are absorbed in small and large intestine along with absorption of various electrolytes so that only 100 ml of liquid and 100 g of solids are excreted in faeces per day
- dec absorption of fluid lead to dehydration
- diarrhoea occurs when capacity of intestine to absorb fluid is dec or secretion of fluid is increased
4) immunity: Gut associated lymphoid tissues (GALT)
- two types - peyers patches (submucosa) and diffuse population of immune cells
- acidic secretion of stomach
5) intestinal bacterial flora - non pathogenic bacteria - essential for many intestinal functions.
- dec flora - impairs intestinal functions
- inc flora - inc susceptibility to diarrhoea and steatorrhea
- also detoxify many toxins
