You will need to know all about the lymphatic system and the medical terminology related to it. The lymphatic system is most directly associated with immunity. Once cleaned by the lymph nodes, lymphatic fluid is released directly into the bloodstream. Lymph vessels are arranged in a similar pattern as the blood vessels, but work to clear the body of impurities.
Lymphatic vessels
Lymphatic vessels borrow their name from the fluid they pump, called, not surprisingly, lymph fluid. Curiously, at the heart of the word lymph is the Greek nymph, a term used to describe a beautiful maiden. The word eventually took on Latin roots, when the n was replaced with l. Because lymph fluid is a clear, clean fluid, and lymph rhymes with nymph, the transition was apparent to Latin wordsmiths.
The lymphatic vessels interlace with blood vessels to carry clean lymphatic fluid through the body. They collect the proteins and water, which continually filter out of the blood into tissue fluid, and return to the blood. The proteins and water filter out of the blood and escape into tissue fluid. The lymphatic vessels pick up the proteins and water from the tissues and return them to the blood.
Lymph nodes, also called “glands”
Shaped much like small beans, the lymph nodes are located throughout the body. Here is the lowdown on the location of these helpful little guys. Lymph nodes are located in several regions of the body. Depending on where they are, lymph nodes are known by different names, including
Axillary: Underarm and upper chest
Cervical: Neck
Inguinal: Groin
Credit: Illustration by Kathryn Born
Lymphatic System
The lymphatic system is largely responsible for creating an immunity barrier by developing and distributing lymphocytes, a type of WBC (white blood cell) throughout the body. Lymphocytes are our little buddies, which you read about earlier. The lymph nodes release these lymphocytes and remove or destroy antigens (foreign substances that invoke an immune response) that circulate through the blood and lymphatic vessels.
Lymph fluid enters the node, filters through sinuses within the node, and drains through a single exit vessel. Consider it a one-way ticket for lymph fluid to get into the bloodstream. This filter system cleans out all the yucky stuff: bacteria, foreign particles, and those naughty malignant cells.
The lymph nodes also destroy invading cells and particles in a process known as phagocytosis. The thoracic duct (there is only one) is the largest vessel of the lymph system. It collects lymph from the body below the diaphragm and from left side of body above the diaphragm.
The spleen, tonsils, and thymus are accessory organs of this system. The spleen enlarges with infectious diseases and decreases in size in old age. Some phagocytosis takes place in the spleen. The tonsils filter out bacteria and foreign matter. The thymus produces cells that destroy foreign substances.