The digestive system
Food is broken down into substances that our bodies can use. This is called Digestion& with out digestion we caouldn't absorb food into our bodies & use it.
Digestion happens in the Digestive system which begins at the mouth& ends at the anus.
Food passes through these organs:
Stages of digestion:
Food is digested in the mouth, stomach& small intestine.
Digested food is absorbed into bloodstream in the small intestine.
Excess water is absorbed back into the body in large intestine.
Undigested food passes out of the anus as faeces.
Liver produces bile which helps digestion of fat. The pancreas produces pancreatic juice aslo know as digestive enzymes.
Passage of food in the gut/ stages of the digestiv
Ingestion- food enters the mouth/beginning of digestive system
Digestion- Food is broken down into smaller molecules
Absorption- Food is absorped into the blood
Egestion- Waste products are excreted.
Mouth- Grind/chew food. Amylase in saliva.
Oesophagus- Food pushed through the Gullet into the stomach.
Stomach- Food is churned&mixed with acid&enzymes. Enzyme Pepsin digests proteins. Works best at pH2.
Small intestine: Pancreatic juice is added. Contains Amylase-Starch digestion
Lipase-fats digestion, Trypsin- Protein digestion.
Pancreatice juice is Alkaline. Bile from liver is added, helps break down fats. Bile&pancreatic juice are BOTH Alkaline.
Food is absorbed into blood.
Bile neutralises acid in the stomach.
Food particles Diffuse into the blood& are carried around the body
Large intestine- water is absorbed.
Rectum- Solid waste/faeces are stored in this part of large intestine/rectum before passing out of the body via the anus.
Villi- tiny finger like projections in small intestine. They increase the surface area of small intestine. Helps absorption of food through the walls of the intestine to the blood.