Lymph, derived from a Latin word, is a fluid that flows through the lymphatic system that is composed of lymph nodes and lymph vessels or channels. Lymph is formed when the interstitial fluid i.e. the fluid that lies in the interstices of all body tissues is gathered through lymph capillaries. Then, it is elated through larger lymphatic vessels to lymph nodes, where materials are eliminated by lymphocytes, before unfilling eventually into the left and right subclavian vein, where it blends with the venous blood.
As the lymph is derived from the intestinal fluid, its composition frequently changes as the blood and the surrounding cells repeatedly swap over materials with the intestinal fluid. It is usually like blood plasma, which is the fluid component of blood. Lymph returns proteins and also surplus intestinal fluid to the bloodstream.
Bacteria might pierce into lymph channels and could be transported to lymph nodes, where they will be destroyed.
The lymphatic system plays a vital role in multicellular organisms since it is responsible for executing multiple interconnected functions. The lymphatic system comprises various parts, which are engaged in various functions.
In human beings and animals, the extracellular fluid, which is present inside the tissue cells, consists of all the fluids of the body. It is divided into plasma and interstitial fluid. Interstitial fluid is the solution that environs the cells and tissues in the body.
Functions of the Interstitial Fluids
The major functions of the interstitial fluids are as follows:
The essential quantity of intestinal fluid is gathered by the lymphatic system and the rest is exhausted out. The exhausted fluid returns back into the major vein and the remaining fluid that is gathered through the lymph capillaries is known as lymph.
The Composition of Lymph
Lymph Plasma
Lymph plasma is like that of blood but has a lesser number of calcium, blood proteins, phosphorus, and a high amount of glucose concentration. Mostly, globulin proteins that are present are in fact antibodies. Further components of the lymph plasma are very much similar to that of blood plasma, water, inorganic and organic substances, etc.
Lymph Corpuscles
Lymph corpuscles are floating amoeboid cells, the white blood corpuscles (the leukocytes), which are typically lymphocytes. Red blood corpuscles (erythrocytes) and platelets are not present in lymph.
Lymphoid Organs
Lymphoid organs are the organs that secrete lymph. In addition to the lymph nodes, thymus gland, tonsils, spleen, and Peyer’s patches are the added lymphoid organs. In the body, the largest mass of lymphatic tissue is the spleen.
Let us discuss these lymphoid organs in detail.
Lymph Nodes – Lymph nodes are bean-shaped tissues that act as filters for the lymph cells before it passes into the blood. Any foreign substances (like germs cells) which are caught by the immune cells are trapped in this filter.
Thymus Gland – The thymus gland is most active in young children, especially around the pre-adolescents phase, after which at puberty, it slowly starts to be replaced by fatty tissues. It is mainly responsible for the production of T cells (a special type of immune cell).
Tonsils – Present in the throat and palate, tonsils play a major role in preventing the germs cells from entering the body via mouth or nose.
Spleen – Spleen is the largest mass of lymphatic tissues in the human body and has many important functions to perform for the healthy functioning of the body. It is mainly responsible for the production of various immune cells to fight antigens or to get rid of the old red blood cells (graveyard of RBCs) etc. It also acts as a store for various immune cells.
Functions of Lymph
- Lymph performs the role of a middle man that transports food materials, hormones, oxygen, etc. to the cells of the body and brings other metabolic wastes and carbon dioxide from the cells of the body to blood. Then, it finally empties them into the venous system.
- Cells of the body are maintained moist by the lymph.
- Lymphocytes are produced by lymph nodes. Lymph takes antibodies and lymphocytes from the lymph nodes to the blood.
- Lymph destroys the attacking foreign particles and microorganisms in the lymph nodes.
- It transports and absorbs fat-soluble vitamins and fat from the intestine. Villi are the lymphatic capillaries that are present in the intestinal villi.
- It brings hormones made in the endocrine glands to the blood and plasma protein macromolecules manufactured in the liver cells.
- It sustains the volume of the blood. Once the volume of the blood is reduced in the blood vascular system, the lymph hurries from the lymphatic system to the blood vascular system.