Lymphatic System

The lymphatic system, also known as the lymph system, consists of a complex network of ducts or tubes and nodes that transport a clear, watery fluid called lymph throughout the body. Lymph is a fluid which contains lymphocytes, a type of white blood cells and antibodies. This system also helps in circulating other essential body fluids and nutrients. It produces the body's defense mechanism which protects the body from disease-causing factors like viruses, bacteria, etc. There are many organs connected to the lymphatic system through a network of tiny capillary tubes. The body is amply supplied by oval or bean-shaped group of tissues called lymph nodes which are situated in the armpit, groin, neck and around the blood vessels of the chest and abdomen.

Lymphatic System Functions

The main function of this vital system is to transport lymph throughout the body. It also defends the body from many infectious diseases.

• The lymphatic system along with the circulatory system transports, oxygen, nutrients and hormones to the cells in the body.
• It also helps the immune system in destroying the harmful pathogens that cause diseases. The lymph, which is made up of lymphocytes and antibodies acts as a barrier to harmful microbes and other foreign bodies. It also helps in expelling and destroying toxic substances from the body.
• This body system helps in maintaining the protein and fluid balance in the body. It helps in collecting the interstitial fluid, filtered by the capillaries, that is rich in proteins and returns it to the blood stream.
• The lymphatic nodes in the gastrointestinal tract aid in absorbing the essential fat from the food we eat and assimilating it in the body. The lymph fluid also helps in preventing obesity by filtering the 'bad' fat from the body.
• The system helps in the excretion of harmful wastes, debris, dead blood cells and excess fluid from the body. It also filters the inter cellular spaces of toxins, cancer cells and pathogens.

Organs of the Lymph System

• Spleen: The spleen is the largest lymphoid tissue in the body. It is a purple colored organ and is situated at the left upper side of the abdomen. It supplies the body with fresh red blood cells and eliminates the old cells. It also produces lymphocytes, which are responsible for producing antibodies to fight against diseases.
• Thymus: Another specialized organ of the immune system is the thymus whose main function is to produce T lymphocytes, also known as T cells. This organ, which is pinkish gray in color, is situated in front of the heart just behind the sternum (or breast bone).
• Tonsils: The tonsils (or palatine tonsils) are a pair of tissue clumps situated on the either side of the throat. Though they are not a part of the immune system, some believe that they help in fighting upper respiratory tract infections.
• Lymph Nodes: Lymph nodes are small bell-shaped organs that are located throughout the body and connected by lymphatic vessels. These nodes consist of white blood cells and assist in the proper functioning of the immune system. They also help in trapping and filtering foreign bodies.

Diseases of the Lymphatic System

Like the other systems of the body, the lymphatic system is prone to many diseases.

• The infection of tonsils or tonsillitis is caused when the gland becomes inflamed and swollen due to certain bacteria. The symptoms of this disorder are sore throat, difficulty and pain while swallowing and fever.
• Splenomegaly or enlarged spleen is caused due mononucleosis, an infection caused due to a virus.
• Another prevalent disorder of the lymphatic system is lymphedema or lymphatic insufficiency which occurs when there is over accumulation of the lymphatic fluid in the interstitial tissues. There are two types of lymphedema - primary and secondary, which are caused due to various reasons. Primary lymphedema is an inherited condition which occurs due to missing or impaired lymphatic vessels. Secondary lymphedema occurs if the lymphatic vessels are disrupted due to infection, surgery or trauma.
• A group of cancer also known as lymphoma occurs when the lymph nodes become enlarged and transform into a malignant tumor. An individual having lymphoma may show symptoms like weak immune function, unexplained weight loss, chronic fatigue, pain after drinking alcohol and night sweats.
• Lymphadenitis, also known as adenitis is the inflammation of the lymph nodes which is caused due to bacterial infection. The skin overlying the node becomes red, tender and appears swollen.

The lymphatic system is the lifeline of the human body, which carries out numerous vital functions. Without this important system, our body would have become prone to many deadly diseases, so it is essential to keep this system healthy and ensure that it functions properly.