- Removing excess fluids from body tissues.
- Making certain types of white blood cells.
Role of the Lymphatic System in Circulation
The lymphatic system collects and returns fluid to the cardiovascular system. A small
amount of fluid leaks from the blood vessels when blood is pumped around your body.
This fluid collects in the spaces between cells and tissues. Some of the fluid returns to the
cardiovascular system, and the rest is collected by the lymph vessels of the lymphatic system,
which are shown inFigure18.8.
The fluid that collects in the lymph vessels is called lymph. The lymphatic system then
returns the lymph to the cardiovascular system. Unlike the blood system, the lymphatic
system is not closed and has no central pump. Lymph moves slowly in lymph vessels. It is
moved along in the lymph vessels by the squeezing action of smooth muscles and skeletal
muscles.
Figure 18.8: Lymph capillaries collect fluid that leaks out from blood capillaries. ( 3 )Role of the Lymphatic System in the Body’s Defenses
The lymphatic system also plays an important role in the immune system. The lymphatic
system makes certain blood cells, and also filters, or traps foreign particles. The lymphatic
system and contain white blood cells to protect the body from infection.
Organs of the Lymphatic System
Along with the lymph vessels, lymph ducts, and lymph nodes, the lymphatic system also
includes many organs. The tonsils, thymus, and spleen, which are shownFigure18.7, each