In brief
A network of delicate tubes that drains fluid from the tissues back into the bloodstream, helps fight infection and helps absorb fats from the gut.
- The lymphatic system plays an important role in absorbing fats from the intestine.
- When swelling from a damaged lymphatic system lasts more than about three months, it is called lymphoedema.
- The spleen filters the blood, removing microbes and old or damaged red blood cells.
How it works
Fluid called lymph leaks from the blood vessels into the tissues. The lymphatic system drains it and empties it back into the bloodstream via the lymph nodes. The larger lymph vessels have muscle in their walls that gently pulsates, and valves stop the lymph flowing backwards.
Lymph nodes filter the lymph. When you have an infection they produce more lymphocytes, a type of white blood cell, which is why they tend to swell. The spleen, under the diaphragm on the left side of the abdomen, and the thymus, behind the breastbone, are part of the system too.
Connections
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Lymphatic system is part of
Lymph nodes trap microbes, and the spleen filters the blood to remove microbes.
Sources: Better Health Channel (Victorian Government), Immune system explained; Better Health Channel (Victorian Government), Lymphatic system
Sources
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Summarised from the Better Health Channel. Sources read on 13 October 2026. General education only, not medical advice. Spotted a mistake? Please tell us through the HuBu-Intel contact page.