Chapter 17 Learning Outcomes

Does an Rh+ mother carrying an Rh- fetus require a RhoGAM injection? Explain your answer.

An Rh+ mother carrying an Rh- fetus does not require a RhoGAM injection because the fetus is not at risk of Rh incompatibility. The fetus is not at risk because its RBCs lack Rh surface antigens, and the mother's plasma lacks anti-Rh antibodies.

Which type of white blood cell would you find in the greatest numbers in an infected cut?

An infected cut would contain a large number of neutrophils, phagocytic white blood cells that are general the first to arrive at the site of an injury.

Why is RhoGAM administered to pregnant Rh- women?

When RhoGAM (which contains anti-Rh antibodies) is injected into a pregnant Rh- woman, the anti-Rh antibodies circulate in the mother's bloodstream, where they destroy any fetal RBCs there. This prevents the mother's immune system from making antibodies against the developing fetus's red blood cells.

What is determined by the surface antigens on RBCs?

Surface antigens on RBCs are glycoproteins in the plasma membrane; they determine blood type.

Identify the components of the cardiovascular system.

The components of the cardiovascular system are the heart, blood vessels (arteries, capillaries, and veins), and blood.

Describe the functional aspects of RBCs.

The functional aspects of RBCs include: (1) large surface area-to-volume ratio that results in a faster exchange of materials between the RBC and its surroundings; (2) the ability to form stacks of cells; and (3) flexibility, which allows RBCs to bend and pass through capillaries that are narrower than their diameter.

Define hematocrit.

The hematocrit, also called the packed cell volume, is the percentage of whole blood volume contributed by formed elements.

Why can't a person with type A blood safely receive blood from a person with type B blood?

A person with type A blood also has anti-B antibodies, so if the person received a transfusion of type B blood, the transfused red blood cells would clump, or agglutinate, potentially blocking blood flow to various organs and tissues.

How do basophils respond to tissue damage?

Basophils enter damaged tissues and release a variety of chemicals, including histamine, which promotes inflammation.

In what way would a liver disease affect the level of bilirubin in the blood?

Bilirubin would accumulate in the blood, producing jaundice, because diseases that damage the liver impair the liver's ability to excrete bilirubin in the bile.

What are the functions of blood?

Blood functions to transport dissolved gases, nutrients, hormones, and metabolic wastes; regulate pH and ion composition of interstitial fluids; restrict fluid loss at injury sites; defend against toxins and pathogens; and stabilize body temperature.

Describe the events that follow the coagulation phase.

Clot retraction and fibrinolysis follow the coagulation phase. The clot consists of fibrin, red blood cells, and platelets. The platelets contract, and the entire clot retracts, pulling the cut vessel edges together. As repairs continue, the clot dissolves through the process of fibrinolysis. Fibrinolysis is activated by plasminogen, which, in turn, activates plasmin, which erodes the foundation of the clot.

Which specific plasma proteins would you expect to be elevated during an infection?

During an infection, you would expect the level of immunoglobulins (antibodies) in the blood to be elevated.

Briefly describe the vascular, platelet, and coagulation phases of hemostasis.

During the vascular phase, local blood vessel constriction (vascular spasm) occurs at the injury site. In the platelet phase, platelets are activated, aggregate at the site, and adhere to damaged blood vessel surfaces. In the coagulation phase, factors released by platelets and endothelial cells interact with clotting factors (through either the extrinsic pathway, the intrinsic pathway, or the common pathway) to form a blood clot, a process involving the conversion of soluble fibrinogen to insoluble fibers of fibrin.

Define hemolytic disease of the newborn (HDN).

HDN is a condition in which maternal antibodies attack and destroy fetal red blood cells, resulting in fetal anemia. It most commonly occurs in a sensitized Rh- mother who is carrying an Rh+ fetus.

Define hemocytoblasts.

Hemocytoblasts form from hematopoietic stem cells. Hemocytoblasts divide in the red bone marrow, producing two types of cells: lymphoid stem cells and myeloid stem cells.

Describe hemoglobin.

Hemoglobin is a protein-composed of four globular subunits, each bound to a heme molecule-that gives RBCs the ability to transport oxygen in the blood.

Define hemostasis.

Hemostasis is the stopping of bleeding. It involves three phases: the vascular phase, the platelet phase, and the coagulation phase.

Explain why venipuncture is a common clinical procedure for obtaining blood for examination.

In venipuncture, blood is collected from a superficial vein. Venipuncture is a common clinical procedure because superficial veins are easy to locate, the walls of the veins are thinner than comparably sized arteries, and blood pressure in the venous system is relatively low, so the puncture wound seals quickly.

Compare the types of cells that lymphoid stem cells and myeloid stem cells produce.

Lymphoid stem cells originate in red bone marrow and give rise to lymphocytes; these stem cells also produce lymphocytes in the thymus, spleen, and lymph nodes. Myeloid stem cells are cells in red bone marrow that give rise to all the formed elements except lymphocytes.

Identify the two types of leukemia.

Myeloid leukemia and lymphoid leukemia.

Identify the five types of white blood cells.

Neutrophils, eosinophils, basophils, monocytes, and lymphocytes.

What is the most common blood type in the United States?

O+

Which blood type(s) can be safely transfused into a person with type O- blood?

O-

Compare oxyhemoglobin with deoxyhemoglobin.

Oxyhemoglobin is hemoglobin whose iron has bound oxygen; it is bright red. Deoxyhemoglobin is hemoglobin whose iron has not bound oxygen; it is dark red.

Compare pernicious anemia with iron deficiency anemia.

Pernicious anemia is insufficient red blood cell production that results from a lack of vitamin B12; the blood cells that do develop tend to be microcytic (abnormally large) and abnormally shaped. Iron deficiency anemia results when the dietary intake or absorption of iron is insufficient, impairing normal hemoglobin synthesis; these blood cells are microcytic (abnormally small).

Describe platelets and their origin.

Platelets are cell fragments that develop from megakaryocytes. These large cells shed their cytoplasm in small, membrane-enclosed packets. These packets are the platelets that enter the bloodstream.

Identify two components making up whole blood, and list the composition of each.

Whole blood is composed of plasma (which contains albumins, globulins, fibrinogen, electrolytes, organic nutrients, and organic wastes) and formed elements (which are platelets, white blood cells, and red blood cells). White blood cells include neutrophils, eosinophils, basophils, lymphocytes, and monocytes.