Untitled Flashcards Set

What is the average volume of blood in an adult?

About 5-6 L, or 7% to 8% of body weight.

What percentage of circulating blood is composed of cells and plasma?

45% cells and 55% plasma.

Where does hematopoiesis initially begin?

In embryonic development.

Which cells do pluripotent stem cells give rise to during hematopoiesis?

Myeloid and lymphoid precursors.

What can stem cells repopulate?

Bone marrow after injury or lethal radiation.

What are the cell types that myeloid progenitors differentiate into?

Erythrocytes, platelets, neutrophils, monocytes, macrophages, eosinophils, basophils, and mast cells.

What factors stimulate the growth of red blood cells?

Erythropoietin hormones secreted by the kidneys.

What is the lifespan of a red blood cell (RBC)?

About 120 days.

What process describes the breakdown of red blood cells?

Destruction and removal by the reticuloendothelial system.

What are the six stages of erythrocyte maturation?

1. Rubriblast, 2. Prorubricyte, 3. Rubricyte, 4. Metarubricyte, 5. Reticulocyte, 6. Mature erythrocyte.

What is the primary function of hemoglobin in erythrocytes?

To carry oxygen to tissues and remove carbon dioxide.

What must hemoglobin contain to combine with and transport oxygen?

A combination of heme (which contains iron) and globin.

What is hypoxia?

A state where oxygen is not available in sufficient amounts at the tissue level.

What are reticulocytes?

Immature red blood cells that differ morphologically from mature RBCs due to RNA presence.

How long does it take for reticulocytes to become fully mature?

1 or 2 days in circulation.

What is the significance of RBC packed volume (microhematocrit)?

It helps in detecting anemia or overproduction of RBCs.

What are some end products of red blood cell destruction?

Wastes excreted in bile, urine, and feces.

What is the role of heme in hemoglobin?

Combines with globin to form an activated form of Hb that carries oxygen.

What is hemoglobin S and its relevance?

It's a variant associated with sickle cell anemia.

What is anemia?

A condition where there is a deficiency in circulating erythrocytes or hemoglobin content.

Define erythrocytes.

Red blood cells responsible for carrying oxygen.

What does leukocytosis indicate?

A high white blood cell count.

What is the primary function of leukocytes?

To protect the body from infection.

What distinguishes granulocytes from non-granulocytes?

Granulocytes contain specific granules in their cytoplasm.

Which type of leukocyte increases during allergic reactions?

Eosinophils.

What are monocytes and their role?

The largest leukocytes that act as phagocytes and can differentiate into macrophages.

What is the distinction between T cells and B cells?

T cells mature in the thymus, while B cells mature in the bone marrow.

What is lymphoma?

A cancer occurring in the lymphatic system.

What does thrombocytopenia refer to?

A low platelet count.

What are platelets and their primary function?

Cell fragments essential for blood clotting.

What is the most common inherited bleeding disorder?

Von Willebrand disease.

What do mature platelets look like under the microscope?

Small, colorless bodies with purplish-red granules.

What can result from too many platelets in the blood?

Increased risk of blood clots, stroke, or heart attack.

What is leukopenia?

A low white blood cell count.

What are the categories of white blood cells?

Granulocytes and agranulocytes.

What is the significance of hemoglobin variants?

They can indicate specific blood disorders.

What role does iron play in hemoglobin function?

It's essential for the primary function of carrying oxygen.

What is the composition of normal adult hemoglobin?

Four heme groups and four globin chains.

What is acute leukemia?

A fast-growing type of blood cancer with malignant cells multiplying in the bone marrow.

What is aplastic anemia?

A condition where the bone marrow stops making new blood cells.

What does it mean if blood cells appear in the peripheral blood in certain disease states?

It's referred to as a shift to the left.

What do basophils release during an allergic response?

Histamine and heparin.

What is the average percentage of neutrophils in peripheral blood?

About 59% of leukocytes.

What does monocytopenia describe?

A decrease in monocyte numbers.

How are sickle cell disease and hemoglobin S related?

Hemoglobin S is the abnormal form of hemoglobin associated with sickle cell disease.

What occurs during immune responses involving normal lymphocytes?

They target infections and cancers through immune reactions.

Which leukocytes primarily fight viral infections?

Lymphocytes.

What does thrombocythemia refer to?

Where the body produces too many platelets.

Describe the function of plasma cells.

They synthesize immunoglobulins (antibodies) from B cells.

What is methemoglobinemia?

A condition where hemoglobin is unable to release oxygen effectively.

What is the role of megakaryocytes in the blood?

They produce platelets.

What is the significance of erythropoiesis?

It's the production of red blood cells.

What condition results from rapid destruction of red blood cells by the immune system?

Autoimmune hemolytic anemia.

Which type of anemia results from vitamin B12 deficiency?

Pernicious anemia.

What happens to RBCs during their maturation process?

They lose their nucleus and become smaller.

What type of cells are commonly affected by acute leukemia?

Malignant white blood cells.

What is the significance of the packed cell volume?

It's an important laboratory measurement in detecting anemia.

How long do eosinophils generally survive in peripheral blood?

Less than 8 hours.

What is the primary function of regulatory T cells?

To help maintain immune tolerance.

What is a common symptom of anemia?

Fatigue.

What condition is characterized by rigid and curved RBCs?

Sickle cell anemia.

What is basophilia?

An increase in the number of basophils.

What does leukocytosis indicate clinically?

Potential infection or inflammation.

What happens to RBCs as they age?

They wear out and are broken down by the reticuloendothelial system.

What are the typical days for RBCs to stay in the bloodstream before they're recycled?

Approximately 120 days.

What causes polycythemia vera?

Bone marrow producing too many RBCs, leading to thickened blood.

What defines a high platelet count?

Thrombocytosis.

What disease is characterized by a decrease in all blood cell lines?

Pancytopenia.