Basic of Blood

Human body consist of blood. Blood is a specialized body fluid that delivers necessary substances to the body's cells such as oxygen and nutrients and transports waste products away.


Red Cells/Erythrocytes

Red cells or erythrocytes are relatively large microscopic cells without nuclei. Red cells normally make up 40-50% of the total blood volume. They transport oxygen from the lungs to all of the living tissues of the body and carry away carbon dioxide.

White Cells/Leukocytes

White cells or leukocytes, exist in variable numbers and types but make up a very small part of blood's volume - normally only about 1% in healthy people. Some white cells (called lymphocytes ) are the first responders for our immune system. They seek out, identify, and bind to alien protein on bacteria, viruses, and fungi so that they can be removed. Other white cells (called granulocytes  and macrophages ) then arrive to surround and destroy the alien cells. They also have the function of getting rid of dead or dying blood cells as well as foreign matter such as dust and asbestos.

Platelets

Platelets or thrombocytes are cell fragments without nuclei that work with blood clotting chemicals at the site of wounds. Individual platelets are about 1/3 the size of red cells.  They have a lifespan of 9-10 days.  Like the red and white blood cells, platelets are produced in bone marrow from stem cells.

Plasma

Blood plasma is the liquid component of blood, consisting of around half of the total blood volume. Plasma itself is around 90% water, with the 10% remainder including proteins, minerals, waste products, clotting factors, hormones, and immunoglobins. Without plasma, blood cells would have no medium to travel on as they moved through the body, and plasma also performs a number of other useful functions in the body.