What forms the majority of blood?

What component of blood accounts for the majority of its volume?

Is it platelets, plasma, leukocytes, or buffy coat?

Final answer:

Plasma forms the majority of blood, accounting for about 55% of its volume.

Plasma forms the majority of blood, accounting for about 55% of its volume. The rest includes erythrocytes, leukocytes, and platelets. Leukocytes are critical for immune defense, while platelets are essential for clotting.

Explanation:

The majority of blood is composed of plasma, which makes up about 55% of its total volume. The remaining elements, including red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes), make up the rest of the blood. Among these components, leukocytes and platelets form a thin layer known as the buffy coat when blood is centrifuged, separating the heavier red blood cells from the lighter plasma.

Leukocytes are essential for the body's immune response, defending against pathogens and foreign substances. There are various types of leukocytes, each with specific functions in the immune system. The main types include granular leukocytes (like neutrophils, eosinophils, and basophils) and agranular leukocytes (like lymphocytes and monocytes). Platelets are crucial for the blood clotting process. They arise from megakaryocytes in the bone marrow and are stored in organs like the spleen. In case of an injury, they contribute to the formation of a clot to prevent excessive bleeding.