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describe digestion in small intestine
 The  food which is churned up in our stomach, a sphincter muscle at the end of our stomach opens to squirt small amounts of food into the top of our small intestine. This first section of the small intestine is called the duodenum.

 The pancreas releases digestive juices through a duct into our duodenum. This fluid is rich in enzymes that break down fats, proteins and carbohydrates. It also contains sodium bicarbonate which neutralises acid produced in our stomach.

The gall bladder squeezes out bile down a duct into our duodenum. Bile helps break down  of fats in our food.

Peristalsis

Digested food is pushed through the small intestine by peristalsis movement. Peristalsis is a muscular movement in which alternating waves of muscle contraction and relaxation cause food to be squeezed along the digestive tract.

Absorbing nutrients

Most of the nutrients in the food we eat pass through the lining of our small intestine into our blood. The lining of the small intestine by finger like  tiny projections called micro villi. These are microscopic, which give the lining of the small intestine a massive surface area for absorption of nutrients to occur across.

Each microvillus contains a minute blood capillary. When nutrients are absorbed into a microvillus, they enter its blood capillary. This is how nutrients from our food enter our blood.

 The undigested  food passes into the large intestine.


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