11 Copyright Goodheart-Willcox Co., Inc. 322 The Blood Chapter 11 Outline Section 11.1 Functions and Composition of Blood • Functions of Blood • Composition of Blood • Manufacturing Blood Cells Section 11.2 Blood Types • ABO Blood Grouping System • Rh Classification System Section 11.3 Blood Disorders and Diseases • Complete Blood Count • Anemia • Other Common Blood Disorders and Diseases P eople have not always had a clear understanding of the life-giving functions of blood. As early as ancient Greece, physicians thought that draining blood from the body, a procedure known as bloodletting, would cure the sick and restore health to the body. This practice continued into the late 1800s. As you may suspect, some individuals did not fare well from bloodletting. Bloodletting contributed to the death of President George Washington. During a brief illness that began with a sore throat and fever, Washington’s physicians bled him. Over the course of 16 hours, physicians drained 5 to 7 pints of Washington’s blood. That is equivalent to 40% to 60% of the body’s supply of blood! Not surprisingly, President Washington died shortly thereafter. Today, people understand the important role that blood plays in maintaining health and sustaining life. For this reason, many people donate their blood to organizations such as the American Red Cross, which maintains blood banks. One pint of donated whole blood can be separated into four different components: erythrocytes (red blood cells), leukocytes (white blood cells), thrombocytes (platelets), and plasma. Each component can be used for different people. This process of using blood, called component therapy, allows more than one individual to benefi t from a single blood donation. According to the American Red Cross, every two seconds someone in the United States will need blood, so blood donations truly do give the gift of life! This chapter describes the functions and composition of blood. It also discusses blood types and common blood disorders and diseases. Clinical Case Study Donya, a pre-med student, was excited to be accepted into the summer abroad program that would provide medical services to underserved people in South America. After a thorough medical exam, including the proper immunizations, she was cleared to go. In addition to making a positive impact on the lives of others, she wanted to immerse herself in the culture as much as possible and was eager to try the foods and customs. After weeks of working long hours assisting the doctors and PAs in treating a wide range of medical disorders, Donya and her classmates helped build a staircase that bridged an impoverished low-lying area to a more affl uent area on a hill. The workers accrued many scrapes and bruises, but the staircase was completed, and everyone feasted on the local cuisine. Donya and the others arrived home exhausted but gratifi ed. In the month that followed, Donya’s exhaustion intensifi ed. She lost weight and developed abdominal discomfort. Her parents insisted that she be evaluated by the family physician. Among the medical conditions and disorders discussed in this chapter, what are the possible causes of Donya’s ailment, and which one is the most likely diagnosis? What types of tests would help evaluate Donya’s condition? JPC-PROD/Shutt erstock.com