What the body does with the food we eat! Nutrition What the body does with the food we eat!

Processing of nutrients Ingestion Digestion Absorption Assimilation Egestion

Ingestion Taking food into the alimentary canal Starts with putting food in your mouth Pulping with teeth Mixing with saliva Swallowing

Upper gastrointestinal tract Mouth Teeth Tongue Pharynx Oesophogus Accessory glands Slaivary glands (submandibular, sublingual, parotid Located around oral cavity Produces amylase to act on polysaccharides

Digestion The process of digestion is triggered by the sight, smell or taste of food. The stomach is a storage bin:- is a food mixer, the strong muscles contract and mash the food into a sticky, slushy mass Is a sterilizing system, where the cells in the stomach produce an acid which kills germs in "bad" food is a digestive tub, the stomach produces digestive fluid which splits and cracks the chemicals in food

Types of digestion Mechanical – Food is physically broken down by teeth and segmentation (small intestines) peristalsis (large intestines) Chemically – Food molecules are broken down by enzymes Bacteria – ferment any remaining carbohydrates and convert proteins into amino acids. Decompose watse.

Chemical digestion Carbo-hydrates Amylases Fats Lipases Tri-glycerides Starches and polysaccharides into disaccharides Mono-saccharides Fats Lipases Tri-glycerides Fatty acids and glycerol Proteins Proteases Peptones and polypeptides Amino acids

Lower accessory organs Gastric glands – produce pepsin and HCI Pancreas – produces enzymes Intestinal glands – produces enzymes to act in small intestine

The liver Produces bile Deactivates amino acids Stores various fats and water soluble vits Synthesises vit A Detoxifies drugs Metabolises alcohol Desaturates fats Produces heat Breaks down worn out blood cells

The Gall Bladder Stores and concentrates bile. Its function is to emulsify fats and neutralise stomach acids

Absorption Mostly happens in the small intestine Ileum – water soluble nutrients, vitamins & minerals Lipids – into lymph Colon – re-absorbs water

Assimilation Happens at cell level Carbohydrates – energy Proteins – structure & repair Fat – insulation, protection & vitamins

Egestion Is expulsion from the alimentary canal Undigested food remains are expelled It occurs through the anus