Why are there so many villi?

Answer 1

Villi are usually found near or in small and large intestine.

Villi's main function is to absorb nutrients from the food and pour it into blood.

Certain villi's absorb lipids and certain ones absorb carbs form the food.

Answer 2

Your lungs lie on either side of your heart and fill the inside of your chest. In an adult, each lung weighs about 1lb. However, the right lung is a little larger than the left because there is more room for it. The left lung has to share its space with the heart.

Two thin layers of tissue, called the pleura, cover each lung. These layers - or membranes - slide over each other as you breathe so that the lungs can expand and contract.

Both lungs are made up of lobes - three on the right and two on the left. The inside of your lungs look like a giant sponge. It is a mass of fine tubes, the smallest of which end in tiny air sacs called the alveoli. There are around 300 million of these alveoli and if they were spread out they would cover a piece of ground roughly the size of a tennis court.

These alveoli have very thin walls. They are criss-crossed with the finest of blood vessels called capillaries.

The lungs are protected by the rib cage. Between the ribs are muscles that are essential for breathing. Below the lungs is a dome-shaped muscle called the diaphragm. The diaphragm separates the chest from the abdomen and is also involved in breathing.

Answer 3

To create a large surface area so as to maximise the amount of absorption that can take place.

Answer 4

This is to allow a larger surface area (for absorption etc) and to allow them to 'wave' unwanted products along (phloem in the oesophagus)

Answer 5

Increases surface area....more places to absorb nurtrients