The thin, narrow structure of the capillaries is well-suited to their function because the capillaries _____.
1. Only carry the liquid portion of blood
2. Transport substances directly to the body cells
3. Require only a small amount of oxygen to function
4. Have the opposite function of arteries and veins
Capillaries unlike arteries and veins in mammals and other organisms due to their size and structure can branch out across multiple regions within the tissues, providing essential nutrients and other compounds.
