Blood Composition and Function

• Blood consists of 45% red blood cells.
• Formed elements in the blood include RBCs, WBCs, and platelets (cell fragments).
• Percent body fat influences blood volume.
• Red blood cells (erythrocytes) are the most abundant formed element.
• Mature red blood cells are biconcave and lack a nucleus.
• Lymphocytes and monocytes are agranulocytes.
• Platelets are thrombocytes, described as small, disc-shaped cell fragments.
• Lymphocytes' primary function is immune support against foreign substances.
• Vitamin B12 absorption is poor in the absence of intrinsic factor.
• Biliverdin and bilirubin are pigments from hemoglobin breakdown, specifically from the heme part.
• The breakdown order of hemoglobin is: Hemoglobin → heme → biliverdin → bilirubin.
• Iron is a component of heme.
• Platelets release serotonin.
• Neutrophils and monocytes function as phagocytes.
• Heparin prevents blood clotting by inhibiting prothrombin activator formation and thrombin's action on fibrinogen.
• Cyanosis occurs when deoxyhemoglobin levels are abnormally high.
• Sickle cell disease's underlying cause is a gene mutation.
• Aplastic anemia is caused by bone marrow destruction.
• Lymphocytes are essential for immunity.
• Diapedesis is defined as white blood cells moving through cell walls.
• Vascular spasm due to serotonin released by platelets stimulates blood vessels to spasm after an injury.
• Erythropoietin controls red blood cell production via a negative feedback mechanism.
• Creatinine is an example of a nonprotein nitrogenous substance (NPN) in plasma.
• Plasma electrolytes include sodium, potassium, calcium, magnesium, chloride, bicarbonate, and phosphate.
• Serum differs from plasma because it does not have fibrinogen.
• A thrombus is a blood clot that forms abnormally in the heart's blood vessel.
• Prothrombin time blood test evaluates the extrinsic clotting mechanism.
• Thrombocytopenia is defined as a below-normal platelet count.
• Type AB blood has A and B antigens on red blood cell surfaces.
• An individual’s blood type is determined by protein antigens on the surface of RBCs.
• Erythroblastosis fetalis may occur when a pregnant woman with Rh-negative blood is pregnant with an Rh+ fetus, typically in the first pregnancy.
• An Rh-negative person does not have the Rh antigen (D).
• Universal precautions include using PPE and hand washing with all patients.
• Leukemia involves overproduction of abnormal white blood cells (immature, leucoblast) and affects blood marrow.
• Plasma albumin helps maintain osmotic pressure.
• A basophil is the least abundant leukocyte in a blood sample.
• Iron is a component of the hemoglobin molecule.
• Enzyme streptokinase and tPA (tissue plasminogen activator) function to dissolve blood clots.
• Cyanosis is caused by an increased blood concentration of deoxygenated hemoglobin (deoxyhemoglobin).
• Hypoxemia stimulates the release of erythropoietin (EPO).
• Platelets are cell fragments released by megakaryocytes.
• Blood flow decreases and becomes sluggish when blood is too viscous.
• Normal blood pH is 7.35-7.45.
• A normal hematocrit value is 45%.
• Hematocrit, RBC count, and hemoglobin concentration values are typically higher in males than females.
• A hematocrit measures the percentage of blood volume occupied by red blood cells.
• A normal white blood cell count is 4,500 per microliter.
• The correct sequence for red blood cell differentiation is: Hemocytoblast → myeloid stem cell → erythroblast → reticulocyte → erythrocyte.
• Pernicious anemia results from a lack of vitamin B12.
• Hemolytic anemia involves red blood cells breaking down faster than they can form.
• Elite athletes might abuse erythropoietin (EPO) for enhanced endurance and performance due to more oxygen to the muscles, causing more ATP.
• A pulmonary embolism is defined as a clot on pulmonary arteries.
• A person with type AB blood can receive all blood types.
• Polycythemia is an increased number of RBCs.
• Leukocytosis is elevated white blood cells.

Explore blood's components: red blood cells, white blood cells, and platelets. Understand their roles, from oxygen transport to immune defense. Learn about hemoglobin breakdown and the importance of factors like Vitamin B12 and heparin in blood function.