IGNIS | Page 14

The Lymphatic and Immune Systems The lymphatic and immune systems, although technically two different systems, are very closely related. The immune system is our defence system – it defends us against foreign organisms, bacteria, fungi and parasitic animals. The lymphatic system is a system of nodes, capillaries and vessels, along with other organs, that transport a fluid called ‘lymph’ from the tissues as it returns to the bloodstream. The lymphatic tissue in these organs filters and cleans the lymph of debris and pathogens. The lymph also contains cells called lymphocytes and macrophages which are part of your immune system. Invaders The types of invaders your immune system and lymphatic system are trying to fight off are: Protozoa There are also living organisms that normally live in the soil or water. They can produce a range of diseases including malaria and diarrhoea. Bacteria Bacteria are life forms found in billions everywhere you look. Not all bacteria are harmful but bacteria known as germs are pathogenic and release poisonous substances called toxins. Viruses Viruses are not living things, they are more like chemical packages. They are made up of genetic material and when they enter the body they invade a cell and then reproduce and spread. 14 IGNIS