Lymph
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:
Interstitial fluid is used for transporting nutrients to the cells.
It is used to offer intercellular communication among the cells.
It is also used in eliminating the metabolic wastes from the cells.
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.
FAQs on Composition of Lymph
1. What exactly is lymph and where is it found in the body?
Lymph is a clear, watery fluid that is very similar to blood plasma but contains fewer proteins and no red blood cells. It is found in the spaces between your body's cells and tissues. This fluid circulates throughout the body in a separate network of vessels called the lymphatic system, playing a key role in both immunity and fluid balance.
2. What are the main components that make up lymph?
The composition of lymph is quite simple. It primarily consists of:
- Lymph Plasma: This is the fluid part, which is mostly water containing proteins, salts, glucose, and urea. It's the fluid that leaks from blood capillaries.
- Lymph Corpuscles: These are the cells floating in the plasma. They are almost entirely lymphocytes, a type of white blood cell that fights infection. Lymph does not contain red blood cells or platelets.
3. How is lymph different from blood?
While both are body fluids, lymph and blood have key differences:
- Colour: Blood is red due to haemoglobin in red blood cells, while lymph is colourless or pale yellow.
- Components: Blood contains red blood cells, white blood cells, and platelets. Lymph lacks red blood cells and platelets but is rich in lymphocytes.
- Function: Blood's main job is transporting oxygen and nutrients, while lymph is crucial for the immune system and draining excess fluid from tissues.
- Flow: Blood circulates in a closed loop powered by the heart. Lymph flows in one direction only, from the tissues back towards the heart.
4. What are the most important functions of lymph?
Lymph performs several vital functions in the body. Its main roles are to act as a 'middleman' for nutrient exchange, drain excess fluid and proteins from tissue spaces, transport digested fats from the intestine, and, most importantly, defend the body against infections by carrying pathogens to lymph nodes where they can be destroyed.
5. How is lymph actually formed in the body?
Lymph formation is a continuous process. As blood flows through tiny blood capillaries, high pressure forces some of the watery plasma out into the spaces surrounding the body's cells. This fluid is called interstitial fluid. While most of this fluid seeps back into the blood capillaries, the rest is collected by a network of tiny lymphatic vessels. Once this interstitial fluid enters the lymphatic vessels, it is known as lymph.
6. Why do doctors sometimes check for swollen lymph nodes when you're sick?
Lymph nodes act as filters for the lymph fluid. They are packed with immune cells called lymphocytes. When you have an infection, the lymph carries the germs (like bacteria or viruses) to the nearest lymph nodes. Inside the node, the lymphocytes multiply rapidly to fight the infection. This intense activity causes the lymph node to swell, which is a sign that your immune system is actively working.
7. If lymph isn't pumped by the heart, how does it move around the body?
Unlike blood, lymph does not have a central pump. Its movement is much slower and depends on the contraction of surrounding muscles. Simple body movements, like walking or breathing, squeeze the lymphatic vessels and push the lymph along. The lymphatic vessels also have one-way valves that prevent the fluid from flowing backwards, ensuring it moves continuously towards the chest to be returned to the bloodstream.
