This video is an introduction to the lymphatic system. It discusses the formation of lymph as well as its composition. It also describes the movement of lymph through the system as well as the anatomy of a lymph node.
The lymphatic system is a network of tissues and organs that help rid the body of toxins, waste and other unwanted materials. The primary function of the lymphatic system is to transport lymph, a fluid containing infection-fighting white blood cells, throughout the body.
The system primarily consists of lymphatic vessels, which are similar to the circulatory system's veins and capillaries. The vessels are connected to lymph nodes, where the lymph is filtered. The tonsils, adenoids, spleen and thymus are all part of the lymphatic system.
- The lymphatic system has three main roles: it is part of our immune system, maintains fluid balance and is essential for the absorption of fats and fat-soluble nutrients.
- Lymph vessels drain fluid from virtually all our tissues to control fluid balance and to deliver foreign material to the lymph nodes for assessment by immune system cells.
- The lymph nodes swell in response to infection - so-called swollen glands - due to a build-up of lymph fluid, bacteria or other organisms and immune system cells.
- Lymph nodes are responsible for filtering lymph and providing part of the adaptive immune response to new pathogens - the part of our immunity that has a long "memory."
- Swollen lymph nodes can indicate a response to foreign material such as from a nearby infection - this process is known as reactive lymphadenopathy.
- Disorders of the lymphatics include lymphedema, a form of swelling occurring when lymph has failed to drain through the lymph vessels.
- If swollen lymph nodes do not return to their normal size, are hard or rubbery and difficult to move, are accompanied by fever, unexplained weight-loss, or difficulty breathing or swallowing, a check-up from a doctor is needed.
Lympthic system and immune function
The lymphatic system forms a major part of our immune response to the continual exposure to micro-organisms. Some such organisms are potentially harmful and even fatal as there are some infections that our immune system is not equipped to deal with.
Swollen lymph nodes can be symptomatic of numerous possible conditions. Glandular fever is one cause of longer-lasting swelling - this viral infection is also known as infectious mononucleosis, or mono.
As a general guide, there is usually no need for people who are otherwise healthy to go to the doctor if common, self-limiting problems such as a cold or influenza can explain swollen glands that settle down.
Children are more prone to swollen lymph nodes because their immune systems are developing responses to infectious microbes.