The Lymphatic System
Lymph nodes (‘glands’) are part of the lymphatic system, which is a network of tiny tubes that carry a colourless fluid called lymph through the skin and deeper parts of the body. Lymph fluid contains immune cells (lymphocytes), nutrients and waste materials.
Figure 1. Position of lymph nodes
Lymph fluid bathes the cells of the skin and internal organs. It drains into lymphatic vessels then larger lymphatic vessels called ducts in the neck before joining the blood stream near the heart (see Figure 1).
Lymph nodes (‘glands’) are small ‘bean-shaped’ nodules that contain millions of infection fighting lymphocyte cells. They are found at intervals along the lymphatic vessels like ‘beads on a string’. The lymph nodes filter out harmful organisms and abnormal cells before the lymph reaches the blood stream.
Lymph nodes can only be felt in certain areas of the body (see Figure 1):
- head and neck
- axilla (armpit)
- inguinal area (groin)
- back of knees
Lymph nodes are usually too small to feel. However, sometimes they can be felt in slim people as smooth pea-sized lumps, usually in the groin. Another time when they can be felt is when you have an infection, (for example, a sore throat or an ear infection which can make the neck lymph nodes enlarged, painful and tender as these are the nearest lymph nodes to the site of infection).
Lymph nodes can also become enlarged if cancer cells lodge in them. In this case, they are usually painless.Download File