It is a system of tiny tubes called lymph vessels and lymph nodes in the human body which transport lymph from the body tissues to the blood circulatory system .
The lymphatic system consists of the following parts:
Lymph capillaries are tiny tubes present in the whole body.
- They are close ended and have bigger pores in their walls than blood capillaries.
- Since the ends of the capillaries are closed, the tissue fluid seeps into the capillary walls through the holes
- Due to their bigger size, larger molecules can enter the capillaries as well.
Larger lymph vessels:
- The lymph capillaries join to form lymph vessels.
- The vessels have lymph nodes at regular intervals.
- The lymph are connected to the larger veins of the circulatory system.
- The lymph nodes contain a special type of cell called lymphocytes.
- Lymphocytes clean the lymph and protect the body from disease. They are a type of WBCs.
- They eat the germs and dead cells and make antibodies.
Lymph is a light yellow fluid somewhat similar in composition to blood plasma.
- It contains protein molecules and digested food , which comes from the tissue fluid between the cells.
- It also contains germs from cells and fragments of dead cells.
- It is a medium of circulation in the body but it flows only from the body tissues to the heart.
- It is called extracellular fluid.
Functions of the lymphatic system:
- Takes part in the nutrition process by circulating proteins from the tissue to the bloodstream.
- Protects the body by killing germs and making antibodies
- Helps in removing waste products like fragments of dead cells etc.