http://www.ck12.org Chapter 1. Human Biology
1.62 Lymphatic System
- Describe the role of the lymphatic system in the immune response.
Do you still have your tonsils?
Many people have their tonsils removed because they can hold on to germs that cause throat infections. Although
sometimes they can do more harm than good, tonsils are there to help you. They trap pathogens so that they can be
destroyed before they enter farther into your body.
The Lymphatic System and the Immune Response
If pathogens get through the body’s first two lines of defense, a third line of defense takes over. This third line of
defense involves the immune system. It is called animmune response. The immune system has a special response
for each type of pathogen.
Theimmune system(Figure1.122) is also part of the lymphatic system—named forlymphocytes, which are the
type of white blood cells involved in an immune response. They include several lymph organs, lymph vessels,
lymph, and lymph nodes.
Lymph Organs
The lymph organs are the redbone marrow,tonsils,spleen, andthymus gland. They are described below (Figure
1.123).
Lymph and Lymph Vessels
Lymph vessels make up a circulatory system that is similar to the cardiovascular system, which you can read about
in a previous lesson. Lymph vessels are like blood vessels, except they move lymph instead of blood.