About Lymph Nodes
The lymph node is an essential part of the lymphatic system. Lymph vessels run through the body in much the same way blood vessels do. The capillaries of the circulatory system leak the plasma and nutrients into the tissues of the body to feed the individual cells. Most of that fluid is not returned to the circulatory system, but rather stays in between the tissue layers as interstitial fluid. This fluid is filtered into the lymph vessels and travels back toward the heart where it will be returned to the circulatory system. When the interstitial fluid enters the lymphatic system the fluid is called lymph. Lymph nodes lie in specific locations along the lymphatic vessels and perform vital functions for the body's immune system.
Geography
Many lymph nodes are situated near the region around the joints. The movements of the limbs help to act as a pump to move the lymph through the system. They are located in clusters around the knee, groin, elbows, shoulders and neck. Lymph nodes are also found in the central abdominal and chest area to assist with lymph drainage around the vital organs.
Features
Each lymph node has afferent and efferent vessels. Afferent vessels are the vessels leading into the node. Efferent vessels are the vessels leading back out of the node at the concave side called the hilum. The node itself is only about the side and shape of a bean. The outer surface of the node is called the capsule. Inside the node there is a cortex and a medulla. The outer cortex has follicles created out of B cells. The inner portion of the cortex contains T cells. The medulla surrounds the cortex and provides the sinuses that allow the lymph to flow through the node. The sinuses of the medulla contain macrophages.
Function
The B cells, T cells and macrophages in the lymph nodes are all types of specialized white blood cells that are designed to fight infection. These cells are in high concentration in the lymph nodes to clean pathogens from the lymph that were collected from the tissue fluid before the lymph is returned to the circulatory system. In this way lymph nodes are a vital part of the immune system.
Considerations
Lymph nodes can become swollen for several reasons. When an infection invades the body, more white blood cells can flood into the lymph nodes to fight the antigen. If there is inflammation in the area of the lymph node, the inflamed cells can enter the node and cause it to swell. Malignant cancer cells can infiltrate the node, causing it to expand. Lymphoma and leukemia also can lead to swollen nodes, caused by the multiplication of cancerous lymphocytes.
Warning
Having swollen lymph nodes by themselves is not necessarily a cause for concern. Doctors recommend seeking medical advice and testing if the swelling is located in the lower part of the neck near the collarbone. If the skin over the nodes is red and inflamed, it could be a sign of an infection that requires treatment. Nodes that become hard, growing rapidly or seem stuck to the skin require attention. If weight loss, night sweats, prolonged fever or fatigue are occurring and the lymph nodes have been swollen for over two weeks a serious infection or condition may exist.
Prevention/Solution
Manual lymph drainage is a type of massage. It stimulates the flow of lymph into the lymphatic capillaries and softens fibrotic tissues. It should not be performed on anyone with cellulitis, a fever or cancer without a doctor's approval. It is a very light massage that can help to drain lymph nodes, improve the lymphatic system function and reduce the swelling of lymph nodes. It was developed in Paris in the 1930s by Dr. Emil Vodder.
Tags: circulatory system, lymph node, lymph nodes, lymphatic system, returned circulatory, returned circulatory system