Red Blood Cells (RBCs): These cells carry oxygen from the lungs to the rest of the body and return carbon dioxide to the lungs for exhalation. White Blood Cells (WBCs): These cells are part of the immune system and help the body fight infection. Hemoglobin: This is the protein in red blood cells that carries oxygen. Hematocrit: This measures the proportion of blood volume that is occupied by red blood cells. Platelets: These cell fragments are essential for blood clotting.
