Lymphatic System Vessels and Nodes
The lymphatic system is a series organs, ducts and nodes that transports lymph fluid throughout the body. Lymph is a clear white liquid similar to blood plasma and contains white blood cells. The white blood cells in the lymphatic system make it part of the immune system. The lymphatic system works in combination with the circulatory system to remove waste from the body's cells.
The circulatory system transports blood containing nutrients to tissues, and collects waste back from tissues. This exchange takes place through intercellular or interstitial fluid surrounding the cells. While about 90% of the waste can be removed by the blood stream, the remaining 10% of waste must be removed by the lymphatic system.
The lymphatic system removes waste such as excess fluid, dead blood cells, pathogens, cancer cells and toxins.
Similar to the circulatory system, the lymphatic system has a series of vessels, called lymphatic vessels. These vessels are used to transport lymph throughout the body. These vessels begin as lymphatic capillaries within the body and then become progressively larger vessels capable of transporting more lymph. These lymphatic vessels are generally located near major veins. Similar to veins, lymphatic vessels have one-way valves to prevent any backward flow. However, unlike the circulatory system, that has the heart to pump blood through the system, the lymphatic system does not have a pump. The lymph is moved through the lymphatic vessels by contractions of the lymphatic vessels and the surrounding skeletal muscles.
As the lymphs travels through the body, it passes through lymph nodes. There are about 600-700 lymph nodes in the body. The lymph nodes filter the lymph by removing waste. Also, white blood cells in the lymph node kill any dangerous pathogens, such as bacteria or viruses. The lymph eventually reaches the subclavian veins, at the base of the neck, where it re-enters the bloodstream as plasma.
Diseases and other problems of the lymphatic system can cause swelling of the lymph nodes and other symptoms.