Using a tiny, spherical glass lens sandwiched between two brass plates, the 17th-century Dutch microscopist Antonie van Leeuwenhoek was the first to officially describe red blood cells and sperm cells ...

Red blood cells transport oxygen throughout your body, including to vital organs and tissues. They also help your body get rid of carbon dioxide. Too little or too many red blood cells may be ...

Using a tiny, spherical glass lens sandwiched between two brass plates, the 17th century Dutch microscopist Antonie van Leeuwenhoek was the first to officially describe red blood cells and sperm cells ...