Whole blood consists of the blood plasma, a fluid extracellular matrix, and formed elements, including cells and cell fragments.
Blood plasma, which makes up about 55% of total blood volume, is a yellowish fluid. It is predominantly water dissolved with vital substances, such as electrolytes and proteins.
It also acts as a medium for carrying nutrients, enzymes, antibodies, hormones, gasses, and blood cells.
Red blood cells, white blood cells, and platelets, collectively known as the formed elements, make up 45% of the blood's volume.
The red blood cells or erythrocytes comprise about 99% of the formed elements; their percentage in the total volume of a blood sample is known as the hematocrit.
The mature erythrocytes are anucleated and contain hemoglobin — a specialized protein that binds and transports oxygen and carbon dioxide between lungs and tissues.
The white blood cells or leukocytes are a group of nucleated cells involved in immune responses.
Lastly, platelets are enucleated cell fragments essential for clotting and repairing damaged blood vessels.
The blood in our bodies comprises three major components: blood plasma, formed elements, and the extracellular matrix. Blood plasma is a yellowish fluid that constitutes 55% of the total blood volume. It is primarily made up of water and essential substances such as electrolytes and proteins. Blood plasma serves as a medium for transporting blood cells and also contains nutrients, enzymes, hormones, antibodies, and gases.
Formed elements constitute the remaining 45% of the blood volume. These elements include red cells, white cells, and platelets. Red cells, or erythrocytes, account for about 99% of the formed elements. The proportion of erythrocytes in a blood sample's total volume is known as the hematocrit. Mature erythrocytes are anucleated and contain hemoglobin, a specialized protein that binds and transports oxygen and carbon dioxide between the lungs and tissues.
White cells, or leukocytes, are nucleated cells involved in immune responses and play a crucial role in defending the body against infections.
Lastly, platelets, small enucleated cell fragments, are essential for clotting and repairing damaged blood vessels.