The immune system is one of the most fascinating & complex systems of the human body. It is the system that identifies potential invaders (and this can be bacteria, viruses, yeast, allergens, mutated cells or free radicals) & destroys them. Most people are unaware of all the organs within the body that function as part of the immune system; these include the thymus, spleen, lymph nodes, gastrointestinal tract, skin & mucus membranes, bone marrow & the liver. Seasonal fluctuations & the onset of colder weather can leave many of us feeling a little run down & in need of an extra lift for our immune systems. A healthy diet as always is essential for the healthy function of this system & taking moderate exercise can also help keep you healthy.