Blood and Cardiovascular System Flashcards

Vocabulary-style flashcards based on the lecture notes for Blood and the Cardiovascular System, covering blood composition, cell types, hemoglobin, anemia, and hemostasis.

Hematocrit

The percentage of red blood cells (RBC) out of the total blood volume.

Blood pH

The normal alkalinity level of blood, ranging between $7.35$ and $7.45$.

Erythrocytes (RBCs)

Anucleate, biconcave discs essentially lacking organelles, filled with hemoglobin ($97\%$) for gas transport.

Spectrin

A plasma membrane protein that provides erythrocytes with flexibility to change shape as they pass through narrow vessels.

Hemoglobin (Hb)

A protein composed of four globin chains each bound to a heme group containing an atom of $Fe^+$, capable of transporting four oxygen molecules.

Oxyhemoglobin

Hemoglobin that is bound to oxygen.

Deoxyhemoglobin

Reduced hemoglobin that has released its oxygen.

Carbaminohemoglobin

Hemoglobin that is bound to carbon dioxide.

Hematopoiesis

The process of blood cell formation which occurs in the red bone marrow of the axial skeleton, girdles, and epiphyses of the humerus and femur.

Erythropoietin (EPO)

A hormone released primarily by the kidneys that stimulates the red bone marrow to enhance erythropoiesis.

Transferrin

The transport protein to which iron is bound while circulating in the blood.

Ferritin

An intracellular protein used for the storage of iron in the liver, spleen, and bone marrow.

Bilirubin

A yellow pigment produced from the degradation of heme that is secreted into the intestine in bile and metabolized to stercobilin by bacteria.

Anemia

A condition in which the blood has an abnormally low oxygen-carrying capacity.

Pernicious Anemia

An autoimmune disease resulting in a deficiency of vitamin $B_{12}$ due to a lack of intrinsic factor needed for absorption.

Thalassemias

A genetic disorder prevalent in the Mediterranean involving absent or faulty globin chains, resulting in thin, delicate RBCs deficient in Hb.

Polycythemia

An excess of red blood cells that results in increased blood viscosity (thickness).

Diapedesis

The process by which white blood cells (WBCs) leave the capillaries to enter surrounding tissues.

Leukocytosis

A condition where the white blood cell count exceeds $11,000/\text{mm}^3$.

Neutrophils

Granulocytes with multilobed nuclei that function primarily to phagocytize bacteria.

Eosinophils

Granulocytes with bilobed nuclei and red granules that kill parasitic worms and destroy antigen-antibody complexes.

Basophils

Granulocytes containing purplish-black granules that release histamine and heparin to mediate inflammation.

Lymphocytes

Agranulocytes with spherical nuclei that mount immune responses via direct cell attack or antibodies.

Monocytes

Agranulocytes with U-shaped nuclei that develop into macrophages in tissues for phagocytosis.

Leukopenia

An abnormally low white blood cell count.

Platelets

Discoid cytoplasmic fragments of megakaryocytes that contain granules and function in the clotting mechanism.

Thrombopoietin

The hormone that regulates the production and development of platelets.

Hemostasis

The fast series of reactions to stop bleeding, consisting of vascular spasms, platelet plug formation, and coagulation.

Fibrin

An insoluble polymer formed from fibrinogen by the action of thrombin, which creates a mesh to stabilize blood clots.

Thrombus

A blood clot that develops and persists within an unbroken blood vessel.

Embolus

A thrombus that has broken away from the vessel wall and is floating freely in the bloodstream.

Thrombocytopenia

A condition characterized by a deficiency in the number of circulating platelets, often resulting in petechiae.

Hemophilia A

The most common hereditary bleeding disorder ($83\%$ of cases) caused by a deficiency of factor VIII.