blood disorders
Overview of Blood
Introduction
Blood is a complex mixture of Plasma (the liquid component) Red Blood Cells (the oxygen-carrying component) White Blood Cells (the cells that defend against infection) Platelets (particles that promote clotting) The body contains about 5 to 6 quarts (about 5 liters) of blood. Blood performs various essential functions as it circulates through the body: Delivers oxygen and essential nutrients (such as fats, sugars, minerals, and vitamins) to the body's tissues Carries carbon dioxide to the lungs Carries waste products to the kidneys for elimination from the body Transports hormones (chemical messengers) to allow various parts of the body to communicate with each other Carries components that fight infection and stop bleeding Carries components that stop bleeding Once blood is pumped out of the heart, it takes 20 to 30 seconds to make a complete trip through the circulation and return to the heart. 