Most people are aware of the existence of the circulatory system, but few know the function of the lymphatic system. Despite this lack of knowledge, lymph plays a fundamental role in the human body. It’s another kind of circuit related to blood, and we can not live without it.
The lymphatic system transports lymph from the tissues to the blood in a unidirectional manner. That is, it has a single path, only in one direction, and does not return.
Lymph is a fluid that is produced in the tissues after filtering the blood. We can say that the beginning of the lymph is the interstitial fluid and that this fluid comes from the blood which the arteries filter and it provides fluid to the cells of the body.
Since it is a filtrate, the lymph will continue to accumulate in the tissues as long as there is blood circulation. To avoid this stagnation, the function of the lymphatic system is to drain it between the cells so that it returns to the blood circulation system.
What are the parts of the lymphatic system?
The lymphatic system fulfills its function in the body through its various components. Lymphatic vessels and lymph nodes are the ones that drive and direct the lymph on its journey. Let’s take a closer look at each part.
As we have already mentioned, lymph is a fluid that comes from the blood filtrate. It is found in tissues as an interstitial fluid and consists mainly of proteins, salts and white blood cells. It is colorless, unlike blood.
To move in the lymphatic system, lymph uses muscle power. There is no pump to drive the circulation, as the heart does with blood. Through usual muscle movement – walking, exercising, performing everyday tasks – the muscle fibers force the lymph to move back and forth.
Lymphatic vessels are an important part of the function of the lymphatic system
Since the blood vessels – arteries and veins – are components of the circulatory system, the lymphatic vessels are designed to conduct lymph. Their wall resembles the vein walls and they also have valves that try to stop the lymph from flowing backwards as it rises.
The lymph vessels introduced into the tissues are so small that they become thinner than capillaries. In this way, they can absorb the interstitial fluid and then conduct it. From the capillaries, these lymph vessels increase in size until they form two primary channels:
- Right lymphatic
Both channels flow into the bloodstream, more specifically, into the venous system. The receiving veins are the cava superior and the left subclavian.
Lymph nodes are the most well-known components of the lymphatic system. Although their function is unclear in the general population, we all know that enlargement of the lymph nodes is a warning of a health problem.
A lymph node is a node in the lymphatic system that measures less than a centimeter under normal conditions. They are generally grouped together where several nodes are close together.
They are responsible for filtering the lymph that passes through them and for producing defense cells, such as white blood cells. Both external microorganisms and defective cells should be filtered by the ganglia so that they do not continue their pathogenic pathway. In these cases, when they detect something abnormal, they increase in size.
Function of the lymphatic system
It is clear that the lymphatic system has a circulatory and protective function. It circulates lymph to supplement the circulatory system and at the same time constantly checks for invasive substances and microorganisms to stop any pathogens.
In summary, we can say that there are three functions in the lymphatic system:
- Circulation : The lymphatic vessels collect lymph from the tissues to empty it into the circulatory system. Through muscular movement, they drive the fluid throughout the body so that it moves and does not stagnate. In addition, it has valves on its way to ensure the alignment of the lymph, which must not go backwards on its route.
- Filtration : The lymphatic system has a filtration function. Some substances are large or molecularly heavy for the circulatory system. In these cases, the lymphatic vessels intervene and transport what cannot be transported by the blood.
- Immunological : The lymph nodes are stations to fight infections. Since they can produce white blood cells, these small organs are activated if they detect a potentially pathogenic foreign compound. They also play a central role in the internal detection of cancer. Lymph nodes can recognize mutated cells that would give rise to tumors, and they even have the ability to remove them.
As you can see, the function of the lymphatic system is crucial. If it did not exist, the circulatory system would not be able to function as it does, we would accumulate fluid in the tissues and we would be much more prone to get few infections.