Medically reviewed by Archana Sharma, DO A mean corpuscular volume (MCV) test is a blood test that measures the size and volume of your red blood cells. Red blood cells carry oxygen from the lungs to ...

Some cells do repairs if you get a cut. Red blood cells deliver oxygen and take away rubbish. And your white blood cells are like police looking for germs. There's a lot going on inside you!

There are four components - or parts - of the blood: red blood cells, white blood cells, plasma and platelets. Blood carries things you need, like oxygen and glucose, and waste products ...