CHAPTER 12 Lesson 1 CIRCULATORY SYSTEM Inflammation Leukocyte Plasma Serum Spectrophotometry Thrombocyte Allergen Anemia Antibody Coagulation Erythrocyte Immunity Journal question: What are the five functions of blood?

Chapter 12 Learning Objectives Define at least 10 terms relating to the circulatory system. Describe two functions of the circulatory system. List five functions of blood.

Chapter 12 Learning Objectives Describe the function of lymph. Identify at least three methods of assessment of the circulatory system. Describe at least five disorders of the circulatory system.

Structure and Function Structure of the circulatory system Includes the blood and lymph that move throughout the body Function of the circulatory system Blood and lymph are tissues that maintain homeostasis and provide immunity.

Blood The body contains approximately 4 to 5 liters of blood, making up about 8% of the body’s weight. Functions Transporting nutrients, oxygen, and hormones Removing metabolic wastes and carbon dioxide Providing immunity with antibodies Maintaining body temperature and electrolyte balance Clotting to prevent bleeding from a wound Hematology is the study of blood.

Hematocrit Blood divides into solid and liquid portions when spun in a centrifuge. The solid parts are called formed elements. The liquid portion is composed of the buffy coat and plasma. Define and discuss the term buffy coat. FIGURE 12-1 Hematocrit.

Red Blood Cells (Erythrocytes) Erythrocytes contain a protein called hemoglobin that carries oxygen to all cells and removes carbon dioxide. Each red blood cell lives 90 to 120 days. New cells are manufactured by the red marrow or myeloid tissue in bones. Hemopoiesis (hematopoiesis) is the process by which a few million new blood cells are made each second. The liver and spleen remove dead red blood cells and reuse the material. More than 25 trillion erythrocytes (red blood cells or RBCs) circulate in the body’s blood. A red blood cell has a strange shape, like a shallow bowl that is round and flat.

Erythrocytes Circulating in the Blood FIGURE 12-2 Erythrocytes circulating in the blood. (Courtesy Ward’s Natural Science Establishment, Rochester, N.Y.)

White Blood Cells (Leukocytes) Remove foreign particles Fight infection Help prevent disease There are fewer white blood cells than red White blood cells are larger than red Leukocytes live about 9 days Pus consists of white blood cells mixed with bacteria. What does it mean when you have a high white blood cell count?

Five Types of White Blood Cells Neutrophils Lymphocytes Monocytes Eosinophils Basophils Discuss the functions of the five types of WBCs – refer to Slide 11 or Table 12-1 in the students’ textbook.

Formed Elements of Blood

Platelets (Thrombocytes) Smallest blood cells Promote clotting to prevent blood loss Can form a plug to seal small vessels by themselves or start the clotting process Produced in red bone marrow Live about 5 to 9 days Discuss how platelets promote clotting. Healthy bone marrow makes a constant supply of red cells, plasma, and platelets. The body replenishes these elements after a blood donation.

Plasma Plasma is a pale yellow liquid that remains when elements are removed from blood. Whole blood is 55% plasma. Plasma is 90% water and approximately 10% proteins. Plasma helps to fight infection and assists in the clotting (coagulation) of blood. Serum is plasma without the clotting proteins. The plasma contains many important proteins, without which you would die. Imagine plasma as a river and the blood cells and platelets as leaves floating in it.

Plasma Plasma contains Nutrients Electrolytes Oxygen Enzymes Hormones Wastes Explain what is meant by the term wastes. Plasma is stored in frozen state and can be used for up to 1 year after collection. Plasma, once thawed, is transfused to treat bleeding disorders when many clotting factors are missing.

Blood Typing A person’s blood type is an inherited characteristic. A blood type is determined by the antigens located on the surface of the red blood cell. Clumping of incompatible cells blocks blood vessels and may cause death. Discuss why blood typing is important. What may happen if you are given the wrong blood type during a transfusion?

Blood Typing Four main blood types A B AB (universal recipient) Person with AB can safely receive any type of blood. O (universal donor) Blood can safely be given to a person with any blood type. Ask the students to identify their blood type if known. Discuss the different blood types of students and the number of students in each of the four main blood groups.

Blood Types

Approximate Distribution of Blood Types in the U.S. Population Have the students identify the blood types from largest to smallest groups by percentage of population. Discuss what they discovered. What is the most common blood type? What is the least common of the four main blood types in the U.S. population?

Blood Typing Rh factor Antigen Found in red blood cells Among North Americans, 85% have Rh-positive blood. Giving Rh-positive blood to a person with Rh-negative blood can be fatal. Considered a foreign particle to the Rh person’s blood and recipient tries to combat it by forming antibodies Rh factor is important in an Rh-negative mother having a second Rh-positive baby. Ask students to give their thoughts on why 85% of North Americans are Rh positive. (The D antigen is the most common Rh antigen and if the D antigen is present, that blood is Rh positive).

Erythroblastosis Fetalis FIGURE 12-3 In erythroblastosis fetalis, an Rh- (Rh negative) mother may form antibodies against the Rh+ blood of a fetus. That infant is not harmed, but when a second Rh+ (Rh positive) fetus is formed, the mother’s antibodies will attack the unborn baby’s blood. (From Patton KT, Thibodeau GA: Anatomy & physiology, ed 7, St. Louis, 2010, Mosby.)

Review Question Blood is pumped from the heart to the body by the largest artery in the body, which is the: a. Arterioles b. Aorta c. Capillaries d. Venules e. Pulmonary artery

Review Question Blood is pumped from the heart to the body by the largest artery in the body, which is the: a. Arterioles b. Aorta c. Capillaries d. Venules e. Pulmonary artery