Functions of The parts of the digestive system
- Created by: GeorgieGipps
- Created on: 23-02-14 19:12
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- Parts of the digestive system.
- 1 Oesophagus
- Tube taking food from mouth to stomach.
- Uses muscle contractions called peristalsis
- Mucus is secreted from tissues in the walls to lubricate foods passage
- 3 Small instestine
- Has two main parts - duodenum and ileum.
- Chyme is moved along the small instestine by peristalsis
- Bile ( alkaline) and pancreatic juice neutralise the acidity of the chyme and breaking it down in to smaller molecules
- Ileum- small soluble molecules ( glucose and amino acids) are absorbed through villi in gut wall.
- Molecules are absorbed by diffusion, facilitated diffusion and active transport.
- 4 Large intestine
- absorbs water salts and minerals
- Has folded wall ( large surface area for absorption)
- Bacteria that decompose some of the undigested nutrients are found here.
- 2 Stomach
- is a small sac with lots of folds so it can expand ( can hold up to 4ltrs of food/liquid)
- Entrance and exit of the stomach is controlled by sphincter muscles
- stomach walls produce gastric juice - helps break down food. It consists of hydrochloric acid pepsin ( enzyme and mucus)
- Pepsin hydrolyses proteins in to smalled polypeptide chains
- Only works in acidic conditions ( provide by HCl.
- Peristalsis of stomach turns food into an acidic fluid called chyme
- 5 Rectum
- Faeces are stored here
- Faeces then pass through the sphincter muscles at the anus during defecation.
- 1 Oesophagus
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