The small intestine

The small intestine is the location where nutrients from food are absorbed.

The small intestine needs to have a suitable structure to allow it to absorb nutrients from food.

The small intestine is highly folded on its inner surface.

The folds also have finger- like projections called villi.

The villi contain 2 different structures for absorbing nutrients from food.

The villi ensure the small intestine is suited to its function in 3 main ways:

• Large surface area

• Thin walls

• Vessels to absorb food

The wall of the villi are only one cell thick.

This means that substances can diffuse into the lacteal or blood capillaries quickly.

Villi contain both blood capillaries and a lacteal.

Blood capillaries absorb glucose and amino acids.

The lacteal absorbs fatty acids and glycerol.