Ch. 25: Structure and Function of the Hematologic System Flashcards
Which of the following is TRUE regarding the constituents of blood?
Plasma is composed of 90% dissolved substances and 10% water.
Blood volume in adults is about 6 L.
Plasma accounts for 10% of blood volume.
Plasma and serum are identical.
Blood volume in adults is about 6 L.
The adult blood volume is about 5.5 L. Plasma is composed of 10% dissolved substances and 90% water. Plasma accounts for 55% to 60% of blood volume. Plasma differs from serum. Serum is altered in the laboratory by removing fibrinogen.
Which component of the blood system is responsible for the critical colloid oncotic pressure? Immune globulins Albumin Gamma globulin Clotting factors
Albumin
Albumin is essential for regulating the passage of water and solutes through the capillaries. The immune globulins are responsible for fighting infection. Clotting factors are responsible for the clotting cascade and the formation of a blood clot.
Which of the following is TRUE regarding erythrocytes?
They comprise 80% of blood volume.
Erythrocytes are responsible for tissue oxygenation.
They contain ribosomes and mitochondria.
They can synthesize proteins.
Erythrocytes are responsible for tissue oxygenation
Erythrocytes carry hemoglobin and are responsible for tissue oxygenation. They do not carry ribosomes and mitochondria; therefore, they cannot divide or synthesize proteins. They comprise 42% to 48% of blood volume.
Which of the following is NOT a granulocyte? Neutrophil Basophil Eosinophil Monocyte
Monocyte
Neutrophils, basophils, and eosinophils are granulocytes. The agranulocytes include monocytes and macrophages.
A person develops a severe urinary tract infection. Which of the following are the predominant cells of early inflammation? Monocyte Neutrophil Basophil Eosinophil
Neutrophil
The neutrophil is the earliest cell of inflammation. Soon after bacterial invasion or tissue injury, neutrophils migrate out of the capillaries and into the inflamed site.
A student looking at a slide notices large cells with a horseshoe-shaped nucleus and no granules present. Which of the following cells are these? Monocytes Macrophages Lymphocytes Natural killer cells
Monocytes
Monocytes are agranulocytic with a horseshoe-shaped nucleus. Macrophages are larger and more active as phagocytes than monocytes. Lymphocytes are the primary cells of the immune response, and natural killer cells kill some types of virus-infected cells.
Which of the following is TRUE regarding platelets?
They are disk-shaped cytoplasmic fragments.
They are formed by clumps of megakaryocytes.
They have a large nucleus.
They divide rapidly
They are disk-shaped cytoplasmic fragments
They are not cells but fragments of cytoplasmic components. They are disk shaped. They fragment from megakaryocytes. They have no nucleus and cannot divide.
Which of the lymphoid organs cluster around lymphatic veins and collect interstitial fluid from tissues? Spleen Bone marrow Lymph nodes Thymus
Lymph nodes
The lymph nodes cluster around lymphatic veins. Their fluid is collected and redistributed through the circulatory system. The spleen is the largest organ of the secondary lymphoid organs. It is the site of fetal hematopoiesis. The thymus and bone marrow are the primary lymphoid organs.
Which of the following is NOT one of the four processes of platelet activation? Adhesion Aggregation Secretion Inhibition
Inhibition
The four processes of platelet activation (clot formation) are adhesion, aggregation, secretion, and procoagulant activity. Inhibition is associated with tissue factor inhibitor and inhibits factor Xa of the clotting cascade.
Which of the following is responsible for lysis or the breakdown of blood clots? Nitric oxide Tissue factor Antithrombin III Fibrinolytic system
Fibrinolytic system
The fibrinolytic system breaks down clots. Nitric oxide causes vasodilation. The extrinsic pathway is activated when tissue factor is released from damaged endothelial cells. Antithrombin III is a circulating plasma protease inhibitor. It inhibits thrombin and factor Xa.
