What is the difference between blood capillaries and lymph capillaries?
Two of the types of capillaries in the human body are blood capillaries and lymph capillaries. The tissues obtain their food from the blood capillaries and when they secrete waste or have extra fluid, the lymph capillaries carry it away.
A capillary tube is a tube that is very tiny in diameter. Blood vessels have capillaries. Arteries are the tubes that carry the blood from the heart to the other organs of the body and it is divided into different branches, such as the small arteries and the arterioles. This division into smaller tubes forms a network of capillaries and small veins branch off from them. Veins carry the blood back to the heart.
The size of the capillaries is small and the walls are very thin. This small size makes the exchange of substances in the capillaries a very easy process. The capillaries take the oxygen and glucose from the arteries and deliver them to the tissues. At the same time, they take the waste products from the tissues and bring them to the kidneys. It is possible for blood capillaries to sometimes leak fluid, but this will be easily absorbed back into the capillaries.
Lymph capillaries contain lymph, which is a fluid that contains lymphocytes (white cells). These capillaries have a larger diameter than the blood capillaries and these are the ones that absorb any fluids that leak from the blood capillaries. However, lymph capillaries do not leak any fluid.
Any obstruction to the lymph capillaries will cause swelling, which is called an oedema. It can also caused decreased levels of protein in the blood, kidney failure or even heart failure and this will cause more fluid to leak into the tissues. The swelling occurs around the ankles and the eyes.
Summary
- Capillaries are tubes that are very small in diameter.
- Blood capillaries carry nourishment to the tissues.
- Lymph capillaries carry waste away from the tissues.