Lymph nodes, also called lymph nodes, are organs formed by lymphoid tissue and are distributed throughout our body. They are located, for example, in the armpits, groin and neck and are attached to lymphatic vessels.
→ Lymph node characteristics
You lymph nodes have varied sizes, some have about 1mm long and others have up to 2 cm. They generally present a bean-like shape. Have a portion called hilo, which is where the arteries enter and the efferent lymphatic vessels and veins exit. In the lymph node, there is also the presence of afferent lymphatic vessels located on the opposite side of the hilum.
They have a capsule that surrounds them and that forms, inside, incomplete shares. Just below the capsule, we have a region called cortical and, further to the center, we have the region called medullar (see the figure below).
Note the structure of a lymph node.
In lymph nodes, we find different cells, such as B lymphocytes, plasma cells, macrophages, reticular cells and dendritic follicular cells.
Plasma cells are normally found in greater numbers in the medulla, compared to the amount in which they are present in the cortical region. We can conclude, then, that the lymph nodes are related to our Imune system.
→ lymph node function
THE lymph node function é filter the lymph (colorless liquid with composition similar to blood plasma), thus ensuring the removal of foreign particles and preventing these enter the circulatory system when the lymph returns. The removal of foreign particles happens thanks to the cells of the immune system that are present in the organ. Lymph circulation in the lymph node follows only one direction, penetrating through the afferent lymphatic vessels through the convex side of the organ and exiting through the hilum through the efferent lymphatic vessels.
Read too:Lymphatic drainage
→ Lymph node enlargement
O lymph node enlargement indicates that something is not right in our body. This swelling indicates that the lymph node is filtering the lymph and removing foreign particles from it. It is worth noting that when lymph nodes are fighting infections, they become painful. Because the lymph nodes enlarge during infections, it is common for the doctors look for this signal when one patient is sick.
Lymph node swelling may indicate an infection.
Neck, groin and armpit have lymph nodes that enlarge and can be felt. Swelling usually occurs in each lymph node area at a time, but more than one area may be affected. This process is called generalized lymphadenopathy.
Curiosity:Named after lymphoma the cancer that starts in the lymph nodes.
By Ma. Vanessa Sardinha dos Santos
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/biologia/o-que-sao-linfonodos.htm