The pressure in the capillaries drives the filtration of water and small molecules from the blood into the space of the tissues.

The correct answers are: Blood pressure and Interstilial space.

Explanation:

In the circulatory system, the blood flows through the blood vessels which include the arteries, veins and capillaries under high pressure.This pressure is generated and provided by the heart as it pumps the oxygenated blood from the left ventricle into the aorta so that the blood reaches the most distant cells of the body to provide them with nutrients and oxygen for the purpose of metabolism.Blood pressure can be defined as the pressure applied by the blood on the walls of the arteries as it flows through them.The walls of the capillaries are extremely thin so when blood flows through the capillaries under high pressure it forces water and small nutrient molecules to move out of the capillaries into the tissue space, also called the interstitial space. The cells in these regions can obtain the nutrients and water from the interstitial space.