The lymphatic system (shown in green)
includes a series of nodes, ducts, and vessels that works closely with the circulatory system and supports the body’s defenses.
Lymph fluid flows through the vessels and nodes, helping the body fight foreign pathogens.
Factoid: The composition of lymph is like that of blood plasma. It contains white blood cells, and picks up bacteria and other waste as it travels.
The lymphatic system is comprised of 5 major components…
The network of lymphatic vessels functions to return lymph to the general circulation.
Lymph that leaks from blood capillaries into the vessels is conducted to the large veins of the neck at the junction of the internal jugular vein and the subclavian vein.
Lymph nodes filter the lymph that passes through the vessels and add lymphocytes to it. White blood cells that produce antibodies target
foreign cells and attack them.
Factoid: Overly large lymph nodes are red flags for doctors, usually indicating an infection or disease.
The thymus is a little organ that sits right above your heart. It is
in the thymus that T-cells–which target pathogens and infections–
mature and become specialized.
Factoid: An infant’s thymus is quite large; as you age, the thymus atrophies and is replaced by adipose tissue.
Tonsils are lymphoepithelial tissues located in your mouth and
throat. There are four sets of tonsils.
The palatine tonsils (highlighted), which are located in the back of your
throat, are commonly known as just “the tonsils.”
Factoid: Did you know that you can live without a spleen? Your liver will take over some of the spleen’s work!
The spleen is the largest organ of the lymphatic system!
The spleen processes blood and removes dead or defective red blood cells, and keeps a reserve of blood in case of hemorrhaging.
It also produces new red blood cells in a developing fetus, and serves as a site where lymphocyte populations increase.
