Biology / Lymphatic System

Lymphatic system

The lymphatic system is the main defense system of the body. It consists of lymph nodes (lymph nodes), ie a complex network of vessels, responsible for transporting lymph from tissues to the circulatory system.

In addition, it has other functions such as the protection of immune cells, as it works with the immune system. Another important role of the lymphatic system is the absorption of fatty acids and the balance of fluids in tissues.

How the Lymphatic System Works

To perform its function of eliminating impurities from our body, the lymphatic system works together with the immune system.

The lymphatic system acts in conjunction with various organs and elements of the body. This is how it can reach every part of the body to filter the tissue fluid it nourished, oxygenated the blood capillaries, and left carrying carbon dioxide and excretions.

Unlike blood that is driven by the force of the heart, in the lymphatic system the lymph moves slowly and with low pressure. It depends on the compression of muscle movements to press the fluid.

It is from the contraction performed by the movement of the muscles that fluid is transported to the lymphatic vessels. As they are larger they eventually accumulate in the right lymphatic duct and the thoracic duct, thus traversing the rest of the body.

Lymphatic System Components

The lymphatic system is formed by different component and organs. Here's what they are and how they work in the body.

Lymph Nodes

Lymph nodes (lymph nodes) are called lymph nodes. They are small organs (up to 2 cm) present in the neck, chest, abdomen, armpit and groin.

Formed by lymphoid tissue and distributed throughout the body, the lymph nodes are responsible for filtering the lymph before it returns to the blood. In addition they also act in the body's defense by preventing the stay of foreign particles in the body.


Lymph is a transparent, alkaline blood-like fluid that circulates through the lymphatic vessels. However, it has no red blood cells and, therefore, has a whitish and milky appearance.

Responsible for the elimination of impurities, lymph is produced by the small intestine and liver. They are transported through the lymphatic vessels in a single direction (unidirectional), filtered by the lymph nodes and released into the blood.

Lymphatic vessels

Lymphatic vessels are channels, distributed throughout the body, which have valves that carry lymph in the bloodstream in one direction, thus preventing reflux.

They act on the body's defense system by removing dead cells and transporting lymphocytes (white blood cells) that fight off infections in the body.


Largest of the lymphatic organs, the spleen is an oval organ located below the diaphragm and behind the stomach.

It is responsible for the body's defense and performs the following functions: antibody production (T and B lymphocytes) and red blood cells (hematopoiesis), blood storage and hormone release.


The thymus is an organ located in the chest cavity near the heart.

In addition to producing substances such as thymosin and thymine, the thymus produces antibodies (T lymphocyte), thus acting in defense of the body.

It is curious to note that the thymus is a lifelong organ that shrinks in size.

Palatine Tonsils

Popularly, these two throat organs are known as the palatine tonsils or tonsils.

They are responsible for the selection of microorganisms that penetrate the body, especially through the mouth. In this case, they assist in the body's defense process as they produce lymphocytes.

Some Lymphatic System Diseases


Filariasis or filariasis is known as an “infectious tropical disease” and corresponds to insect-transmitted lymphatic vessel inflammation (mosquito culex).

Its name is associated with fluid retention or swelling of the limbs, making patients' legs look elephantic.


Characterized by inflammation and obstruction of lymphatic vessels, lymphedema leads to excessive swelling of the limbs.

Curiosities about the lymphatic system

  • Other diseases associated with the lymphatic system are cellulite (fat accumulation), alleviated with the treatment of lymphatic drainage; the tongue (swollen lymph nodes) and some cancers ( lymphoma ), for example breast cancer.
  • In the human body, lymph is more abundant than blood.