Four Components of Blood

Blood is a specialized body fluid. It has four main components: plasma, red blood cells, white blood cells, and platelets. Blood has many different functions, including:

• transporting oxygen and nutrients to the lungs and tissues
• forming blood clots to prevent excess blood loss
• carrying cells and antibodies that fight infection
• bringing waste products to the kidneys and liver, which filter and clean the blood
• regulating body temperature

The blood that runs through the veins, arteries, and capillaries is known as whole blood, a mixture of about 55 percent plasma and 45 percent blood cells. About 7 to 8 percent of your total body weight is blood. An average-sized man has about 12 pints of blood in his body, and an average-sized woman has about 9 pints.

Blood Components:

Red Blood Cells

• make up 40-45% of blood volume
• have a lifespan of 120 days
• carry oxygen throughout the body

Plasma

• makes up 55% of blood volume
• mixture of water, sugar, fat, protein and salts
• transports blood cells, nutrients and waste throughout the body

White Blood Cells

• make up only 1% of blood
• they fight against infection

Platelets

• its primary function is to help blood clot