BMS201 || L5 Quiz

Anemia Definitions and Types

• Anemia is characterized by a decrease in the oxygen-carrying capacity of the blood due to low hemoglobin levels.
• Acute blood loss anemia results in normocytic, normochromic red blood cells immediately following loss.
• Chronic blood loss anemia commonly produces microcytic, hypochromic red blood cells, often due to iron deficiency.
• Aplastic anemia occurs due to failure of bone marrow function, leading to decreased production of red blood cells.
• Megaloblastic anemia is linked to vitamin B12 deficiency, resulting in abnormally large red blood cells.
• Hemolytic anemia can stem from various causes, but is not caused by iron deficiency.

Sickle Cell Anemia and Erythroblastosis Fetalis

• In sickle cell anemia, abnormal hemoglobin (HbS) precipitates under low oxygen conditions, causing cell sickling.
• Erythroblastosis fetalis results from Rh-positive blood cells in a fetus attacked by antibodies from an Rh-negative mother.

Anemia Effects on Blood and Vascular System

• Anemia decreases blood viscosity, which subsequently reduces peripheral resistance.
• Increased blood flow in anemia is due to decreased peripheral resistance and hypoxia-induced vasodilation.
• Cardiac output typically increases in anemia as the body compensates for reduced oxygen carrying capacity.
• Cardiac reserve decreases because the heart must work harder to maintain oxygen delivery despite anemia.

Polycythemia Definitions and Effects

• Polycythemia refers to an increase in red blood cell count, leading to increased blood viscosity and peripheral resistance.
• Secondary polycythemia can occur in response to hypoxia, obstructive lung diseases, or living at high altitudes.
• Blood flow velocity decreases in polycythemia due to increased viscosity and resistance, despite increased overall blood cell count.

Symptoms and Other Characteristics

• The typical skin color in anemia is pallor, while polycythemia often leads to a reddened skin appearance.
• Patients with megaloblastic anemia present with abnormally large red blood cells, contrasting with hereditary spherocytosis, which shows small, spherical cells.
• A "water hammer pulse" may be observed in polycythemia, indicating significant cardiovascular effects.

Heart and Blood Pressure Dynamics

• Anemia tends to initially increase blood pressure, but may drop if heart failure occurs.
• In severe anemia, blood viscosity can fall to 1.0 times that of water, impairing oxygen delivery due to low hemoglobin concentration.

General Anemia Causes and Symptoms

• Common causes of aplastic anemia include excessive X-ray irradiation and chronic blood loss.
• Typical symptoms of anemia are fatigue, shortness of breath, pallor; cyanosis is not a typical symptom.
• The rapid formation of new red blood cells, characteristic of polycythemia vera, compensates for destroyed cells.

Key Functional Roles

• Intrinsic factor is crucial for vitamin B12 absorption, necessary for red blood cell production.
• Hypoxia stimulates red blood cell production, driving secondary polycythemia and compensatory mechanisms in the body.

For complaints and inquiries, contact us on WhatsApp,, Contact number: 01098417407