Blood has two main components:
* Plasma: This is the liquid part of your blood, about 55% of its total volume. It's mostly water, but it also contains proteins (like albumin, antibodies, and clotting factors), hormones, nutrients, and waste products. It acts as the transport medium for everything else.
* Formed Elements: These are the actual cells and cell fragments suspended in the plasma, making up about 45% of your blood volume. There are three main types:
* Red Blood Cells (Erythrocytes): These are by far the most numerous. Their main job is to carry oxygen from your lungs to your body's tissues and bring carbon dioxide back to your lungs. They contain a special protein called hemoglobin which binds to oxygen.
* White Blood Cells (Leukocytes): These are your body's defenders, part of your immune system. There are several types (neutrophils, lymphocytes, monocytes, eosinophils, basophils), each with slightly different roles in fighting infections and diseases.
* Platelets (Thrombocytes): These are not full cells but small fragments that play a critical role in stopping bleeding by forming clots.