Lymphatic System

 Parts of Lymphatic System

It is the second important circulatory system in the human body that transports the liquid from the body tissues to the blood vascular system. The lymphatic system consists of the following parts.

(a) Lymph

It is a light yellow-coloured fluid. Its colour is due to absense of red blood corpuscles. The lymph is also called as the extra-cellular fluid as it bathes the tissue which is found outside the cells. Lymph flows in only one direction i.e., from body tissues to the heart. It consists of two parts namely,

(i) Plasma
(ii) Lymphocyte

The plasma is a fluid matrix which contains protein molecules, digested fats etc. The lymphocyte is a special type of white blood corpuscles which helps to fight infection and disease.

(b) Lymph Nodes

Lymph nodes are located at intervals on the lymph vessels throughout the lymphatic system. In the lymph nodes, the lymph is cleaned by lymphocytes, which kill germs and also produce antibodies to protect the body from disease.

(c) Lymph Capillaries

These are tiny tubes present throughout the body. The ends of the lymph capillaries in the body tissues are closed and thus, only the tissue fluid can seep into the walls of the lymph capillaries.

(d) Lymph Vessels

These are large tubes containing vessels. These are formed by joining lymph capillaries. They finally join the venous system near the heart.

Functions of Lymph or Lymphatic System

The functions of lymphatic system include the following:

(i) Lymph protects the body by killing the germs.

(ii) Lymph drains the excess of fluid from extracellular spaces back into the blood.

(iii) Lymph carries carbon dioxide and nitrogenous waste materials from tissues to the blood.

(iv) Lymph is involved in nutritive process by carrying the proteins and digested fat.