red blood cells stream in vein. abstract white blood cell in vena. microscope closeup view. science 3d

3d abstract anatomy artery background biological biology blood bloodstream body capillary care cell cells closeup disease flow flowing group health healthy hemoglobin human illness illustration immune immunology infection life macro medical medicine micro microbiology microscope microscopic organic organism red science scientific sick sickness stream system thrombosis vein vena vessel view virus vital white