◾ The immune system is the body’s defense network, protecting against infections, toxins, and harmful invaders. ◾ Tonsils and adenoids act as the first barrier, trapping germs entering through the mouth and nose. ◾ The thymus is where T-cells mature, preparing to fight infections. ◾ Lymph nodes filter pathogens and activate immune responses. ◾ Lymphatic vessels transport lymph fluid carrying immune cells throughout the body. ◾ Bone marrow produces white blood cells, the soldiers of immunity. ◾ T

Microbes – bacteria and fungi – live everywhere, even on the station. NASA scientists are testing DNA sequencing on the station to identify the tiny residents and keep crews safe. Read more: https://go.nasa.gov/2IbtgAL | International Space Station