Module 19: Blood Components

blood plasma

a watery liquid extracellular matrix that contains dissolved substances

formed elements

cells and cell fragments

55%

percentage of blood that is plasma

45%

percentage of blood being formed elements

albumins

most numerous plasma proteins that play a role in transport and exchange of fluids across blood capillary walls

globulins

plasma proteins that function as either antibodies that help attack viruses and bacteria or transport proteins for iron, lipids, and fat-soluble vitamins

fibrinogen

plasma protein that plays an essential role in blood clotting

hemopoiesis

the process by which the formed elements of blood develop in bone marrow

pluripotent

stem cells that have the capacity to develop into many different types of cells - including either myeloid or lymphoid stem cells

myeloid

type of stem cell that give rise to red blood cells, platelets, monocytes, neutrophils, eosinophils, basophils, and mast cells

lymphoid

type of stem cell that give rise to T and B lymphocytes and natural killer cells

erythrocyte

formed element that transports most oxygen and part of the carbon dioxide in blood

hemoglobin

oxygen-carrying protein that gives blood its red color

globin

protein portion of hemoglobin containing 4 polypeptide chains

heme

ringlike nonprotein portion of hemoglobin that binds iron (Fe)

iron

ion portion of hemoglobin that binds oxygen

vitamin B12

vitmanin required for proper RBC synthesis - deficiency can cause pernicious anemia

transferrin

transport protein for iron in the bloodstream

bilirubin

yellow-orange metabolite of heme - transported to the liver for removal

spleen, liver, bone marrow

organs that contain macrophages that remove old RBCs from circulation

sterocobilin

brown metabolite of heme eliminated in feces

erythropoietin (EPO)

hormone produced by kidneys that stimulates erythropoiesis (RBC production)

hematocrit

percentage of blood volume occupied by RBCs

Sickle cell anemia

genetic defect in the gene for hemoglobin

polycythemia

high percentage of RBCs in blood

neutrophil

60-70% of circulating WBCs; phagocytosis during early inflammation; can destroy bacteria using lysozyme, hydrogen peroxide; and defensins

eosinophil

2-4% of circulating WBCs; combat effects of histamine in allergic reactions; can destroy certain parasitic worms

basophil

0.5-1% of circulating WBCs; release histamine, heparin, and serotonin during allergic reactions that intensify inflammation

lymphocyte

20-25% of circulating WBCs; mediate immune responses including production of antibodies and attack of viruses, cancer cells, and transplanted tissue cells

monocyte

3-8% of circulating WBCs; transform into macrophages that phagocytose

platelet

form temporary "plug" during hemostasis

tPA

genetically engineered human enzyme use as a thrombolytic agent to dissolve blood clots

ADP and thromboxane A2

molecules released by platelets that activate nearby platelets

aspirin

nonsteroidal anti-inflammatory drug given in low doses to reduce the chance of a thrombus (blood clot)

vascular spasm

vasoconstriction that occurs immediately following damage to blood vessels

prothrombinase

formation of this marks the beginning of the common pathway of blood clotting

thrombin

enzyme that converts fibrinogen into fibrin

tissue factor (TF)

released from damaged cells, this mixture of lipoproteins initiates the extrinsic pathway

vitamin K

vitamin required for the synthesis of 4 clotting factors

plasmin

enzyme that dissolves the clot during fibrinolysis

fibrin

thread-like protein that reinforces the platelet plug

heparin

anticoagulant produced by mast cells and basophils

collagen

when a blood vessel is damaged, platelets adhere to this connective tissue protein

streptokinase

first thrombolytic agent approved that is used to dissolve blood clots. Naturally produced by streptococcal bacteria

Serotonin and thromboxane A2

molecules released by platelets that function as vasoconstrictors

calcium

cation required for multiple steps during blood clotting

coumadin

anticoagulant drug that reduces vitamin K levels and therefore 4 clotting factors