Food and digestion 3

What happens in the mouth

Food is chewed by teeth, amylase breaks down starch

Swallowing reflex

The larynx moves upwards and tips the epiglottis over the glottis preventing food from entering the trachea

What happens in the stomach

the stomach wall secrets hydrochloric acid to kill bacteria, pepsin is secreted to break down proteins to peptides

Chief cells

secrete pepsin

What does peristalsis do in the stomach

the churning action of the stomach mixes the bolus with the acid, the stomach sphincter relaxes to let in food in into the small intestine

What happens in the duodenum

pancreatic juice is secreted, bile is secreted to break down lipids

Bile

stored in the gall bladder, turns large lipid globules into an emulsion of tiny droplets. It also neutralises acidic food

What happens in the small intestine

monosaccharides, amino acids , glycerol and fatty acids are absorbed

What happens in the large intestine

water is reabsorbed back into the blood

Villi

contain microvilli that increase the surface area for absorption. Have a good blood supply to absorb food and lacteal tube to absorb fats

Lacteal tube

is part of the lymphatic system