Red Blood Cell Production and Disorders

Red Blood Cells (RBCs) live for about 120 days.

Hemoglobin has 4 subunits: 2 alpha and 2 beta.

RBCs are made in bone marrow.

A condition with an increased number of RBCs, blood thickens too much.

Symptoms include pale skin, blue skin, flushing, difficulty breathing & muscle weakness.

Caused by a deficiency in folic acid or vitamin B12.

Most common; caused by insufficient iron, blood loss, pregnancy or neoplasia.

Reduced RBC concentration, not due to a decrease in RBC counts, but due to increased plasma volume.

Acute pain, tissue damage (ischemia), lung infarcts, stroke, and avascular necrosis, caused by abnormal red blood cells.

Inherited blood disorder causing insufficient red blood cell production (hemolysis) due to mutations in alpha or beta chains of hemoglobin.

Blood clotting process initiated by endothelial damage, activating platelets & coagulation cascade; to limit blood flow and form a plug, in a process of positive feedback

Hemostasis promotes blood clotting, anti-coagulation opposes it, inactivating factors to prevent inappropriate clots.

Blood clot in a vein, often in the leg, causing symptoms like pain, swelling and dilated veins, leading to embolism if the clot moves to other organs.

Bleeding disorder, deficient Factor 8 impairs blood clotting.

Increased tendency for abnormal blood clot formation.

Bleeding disorder caused by a deficiency or defect in von Willebrand factor (vWF) making it hard to stop bleeding properly.

Thrombus formation refers to the development of an inappropriate blood clot within a blood vessel, obstructing blood flow.

Venous Thrombosis, commonly known as DVT, occurs when a blood clot forms in a vein, particularly in the lower leg.

When a thrombus breaks free and travels through the bloodstream, it becomes an embolism. This can cause significant complications depending on where it lodges.

A pulmonary embolism occurs when a blood clot travels to the lungs, disrupting oxygen and blood flow, leading to breathing difficulties and chest pain.

Factor V Leiden is a genetic mutation that increases the risk of forming blood clots, primarily DVT.

Virchow's Triad describes the three primary contributors to thrombus formation: endothelial damage, alterations in blood flow, and hypercoagulability.

Hemophilia A is a bleeding disorder caused by a deficiency in Factor VIII, a crucial clotting factor.

While both Hemophilia A and B are bleeding disorders, Hemophilia A is due to Factor VIII deficiency, while Hemophilia B is caused by a lack of Factor IX.

Iron is essential for the synthesis of hemoglobin, the protein responsible for oxygen transport in red blood cells.

Both vitamin B12 and folate are essential for DNA synthesis, which is crucial for the proper development and division of red blood cells in the bone marrow.

Red blood cells are produced in the bone marrow, a soft tissue found inside bones.

Red blood cells have a lifespan of approximately 120 days, after which they are broken down and recycled.

Old red blood cells are engulfed by phagocytes, mainly in the spleen and liver. The heme portion of hemoglobin is converted into bilirubin, which is excreted in feces.

Polycythemia is a condition characterized by an abnormally high number of red blood cells, resulting in thicker blood and a lower plasma volume.

There are two main types: relative polycythemia, caused by decreased plasma volume, and absolute polycythemia, caused by an increase in red blood cell mass.

Anemia is a condition characterized by a lower than normal number of red blood cells or decreased hemoglobin levels, resulting in reduced oxygen carrying capacity.

Vitamin B12 and folic acid are vital for DNA synthesis, a process essential for the division and maturation of red blood cells. Deficiencies can lead to megaloblastic anemia, where large, immature red blood cells are produced.

Red blood cells have a lifespan of about 120 days. When they age, they are removed from circulation by phagocytes, primarily in the spleen and liver. The heme portion of hemoglobin is broken down into bilirubin, which is then excreted in feces.

Relative polycythemia is caused by a decrease in plasma volume, making the blood appear thicker. Absolute polycythemia, on the other hand, is due to an actual increase in the production of red blood cells.

Megaloblastic anemia is caused by a deficiency in either vitamin B12 or folic acid, essential for DNA synthesis. Without them, the body produces large, immature red blood cells, which cannot function properly.

Iron-deficiency anemia is the most common type of anemia and is caused by a lack of iron in the body, which is essential for hemoglobin production. This results in smaller, pale red blood cells that cannot carry enough oxygen effectively.

Sickle Cell disease can lead to ischemia and tissue damage, causing acute pain. It can also cause lung infarcts, stroke, avascular necrosis, and pigment gallstones.

Treatment for sickle cell disease involves blood transfusions to replace unhealthy red blood cells with healthy ones, and hydroxyurea, a chemotherapy drug that increases production of fetal hemoglobin, which is less likely to sickle.

Thalassemia is an inherited blood disorder caused by mutations on the alpha or beta chains of hemoglobin, leading to insufficient red blood cell production and hemolysis.

Hemostasis is the process of blood clotting. After endothelial injury, platelets are activated, releasing ADP and thromboxanes. These stimulate vasoconstriction, make platelets sticky, and activate other platelets through positive feedback. This forms a plug and triggers coagulation.

Anti-coagulation opposes clot formation. It inactivates factors Xa and VIIa, which are part of the Tissue Factor Pathway secreted by endothelial cells.

Thrombus formation is the inappropriate formation of a blood clot within a blood vessel. It is usually caused by Virchow's Triad - endothelial damage, altered blood flow, and hypercoagulability.

A pulmonary embolism occurs when a clot travels to the lungs, leading to symptoms like dyspnea, tachycardia, pleuritic chest pain, and cough.

Factor V Leiden is a genetic mutation that increases the risk of DVT due to a mutated version of Factor V in the clotting cascade, which makes it less easily inactivated by Protein C.

Normal RBC production requires adequate bone marrow, sufficient iron for hemoglobin synthesis, and adequate vitamin B12 and folate for DNA synthesis.

RBCs develop in the bone marrow over a week, accumulating hemoglobin. They enter circulation as immature reticulocytes, which mature into mature RBCs and lose their nuclei within a few days.

Red blood cells have a lifespan of approximately 120 days.

Hemolysis is the breakdown of RBCs. It plays a crucial role in regulating RBC count and maintaining normal blood volume.

Polycythemia is an increase in RBC mass. Relative polycythemia is caused by a decrease in plasma volume, while absolute polycythemia is caused by an increase in RBC production.

Anemia is a decrease in the number of RBCs or hemoglobin. It can be caused by dysfunctional RBC production, abnormal destruction, genetic abnormalities, nutritional deficiencies, chronic disease, and blood loss.

Megaloblastic anemia is caused by vitamin B12 or folate deficiency. It results in the production of large, oval-shaped RBCs that are immature.

Iron-deficient anemia is the most common type. It's caused by insufficient iron intake or loss. It leads to small, pale RBCs with reduced hemoglobin.