Chapter 19, Problem 1CYU

What is lymph? Where does it come from?

Summary Introduction

To review:

Definition and origin of lymph.

Introduction:

The lymphatic system collects the fluids that have leaked from the vascular system and returns them to the blood. It consists of a network of lymphatic vessels, the fluid called lymph and the lymph nodes that cleanse the lymph. The lymphoid organs and tissues, such as the spleen, thymus, and tonsils, are present throughout the body and help develop immunity.

Explanation of Solution

There is an exchange of nutrients, waste materials and gases between the blood and the interstitial fluid. The leaked fluid in the interstitial spaces contains a high amount of proteins and enters the lymphatic vessels. This fluid is called lymph and is returned to the bloodstream through the lymphatic vessels. Lymph is derived from interstitial fluid and thus, it resembles plasma.

There is a unidirectional flow of lymph; capillaries collect lymph and then transport it to larger lymphatic vessels. Lymph can also contain absorbed fat from the small intestines. These lymphatic capillaries are called lacteals and transport fat to the bloodstream. This fatty lymph is called chyle and it drains from the villi present in the mucosal layer of the small intestines.

Conclusion

Thus, it can be concluded that the interstitial fluid is called lymph when it enters the lymphatic vessels. It comes from the blood.