BIOLOGY DIGESTIVE SYSTEM

The mouth

Break down food with teeth

Amylase enzyme from salivary gland begins to breakdown starch into shorter chains

food forms into bolus

The Oesophagus

Mucus aids the movement of food down the oesophagus via peristalsis

Mucus

A jelly gel like fluid

Peristalsis

A wave of muscle contractions

The Stomach

Muscular extension of the gut for mechanical and chemical breakdown of food

food is converted into chyme

The stomach expansion causes the lining of the cells to secrete gastric juices

chyme stays in the stomach

The Pancreas

Releases bio carbonate and enzymes

The bio carbonate needs to be released into the duodenum

without it the acid from chyme will damage the intestinal walls

Gall bladder

Produces bile

Bile salts emulsify fats to aid Lipase enzyme activity

stoles excess bile

Endocrine gland stores Glucose as Glycogen

Liver

Produces bile

Bile salts emulsify fats to aid Lipase enzyme activity

main processing organ where products of cell metabolism are detoxified

proteins are made

old red blood cells are broken down and hormones are produced

Small Intestine

Longest part of the digestive tract

three regions

main site of food digestion as enzymes are secreted by the Pancreas and cells lining the intestine

site of absorption

Villi and microvilli of lining cells aid in absorption

Duodenum

shortest and first section

winding tube connecting large intestine to stomach

Jejunum

Middle section and heavily folded

Ileum

Final and longest section

absorbs remaining nutrients

Large intestine

Colon and Rectum

Bacteria in colon digest fibre into fatty acids

further water consumption

produces Faeces which is stored in the rectum