Pathophysiology of Megaloblastic Anemia: Megaloblastic anemia is a type of anemia caused by impaired DNA synthesis, resulting in abnormal maturation of hematopoietic cells, particularly erythroid precursors in the bone marrow. The two major nutritional causes are vitamin B12 (cobalamin) deficiency and folate (vitamin B9) deficiency. The characteristic feature is nuclear-cytoplasmic asynchrony: cytoplasmic maturation continues relatively…
Mechanism of Inflammation: Inflammation is a protective biological response of living, vascularized tissues to harmful stimuli such as infection, tissue injury, trauma, chemical irritation, toxins, and foreign bodies. Its primary purpose is to eliminate the initial cause of injury, remove damaged cells and tissues, and initiate tissue repair. Inflammation is not itself a disease. It…
Rh Factors and Blood Transfusion: The Rh blood-group system is one of the most important blood-group systems in transfusion medicine after the ABO system. The term Rh factor most commonly refers to the D antigen, a protein present on the surface of red blood cells in some individuals. People who possess the D antigen are…
Composition and Functions of Blood: Blood is a specialized fluid connective tissue that continuously circulates through the cardiovascular system. It is essential for maintaining life because it connects almost every organ and tissue of the body with one another. Blood transports oxygen from the lungs to tissues, carries carbon dioxide from tissues back to the…
What are Body Fluids: Body fluids are the liquid components present within the human body that provide an essential medium for the transport of nutrients, gases, hormones, metabolic waste products, electrolytes, and other substances. Water is the major component of body fluids and accounts for approximately 50–60% of the total body weight in a healthy…
Pathophysiology of Hemophilia : Hemophilia is a rare genetic bleeding disorder characterized by the deficiency or dysfunction of clotting factors in the blood, primarily factor VIII (hemophilia A) or factor IX (hemophilia B). This results in prolonged or spontaneous bleeding episodes, which can lead to serious complications. This note explores the causes, types, symptoms, diagnosis,…
Pathophysiology of Hereditary and Acquired Anemia: Hereditary and Acquired Anemia: Anemia is a condition characterized by a deficiency in the number or quality of red blood cells (RBCs) or hemoglobin, leading to reduced oxygen-carrying capacity of the blood. Anemia can be broadly categorized into hereditary and acquired types, based on its underlying cause. This note…
Pathophysiology of Thalassemia: A thalassemia is a group of inherited blood disorders characterized by the body’s inability to produce sufficient and functional hemoglobin, resulting in anemia. Hemoglobin, the protein in red blood cells responsible for carrying oxygen, has two main components: alpha and beta globin chains. Thalassemia is categorized based on which globin chain is…
Pathophysiology of Sickle Cell Anemia: Sickle cell anemia is a hereditary blood disorder characterized by the production of abnormal hemoglobin, known as hemoglobin S (HbS). This leads to the deformation of red blood cells into a sickle shape, which causes various complications including pain, anemia, infections, and organ damage. This note explores the genetic basis,…
Lymph nodes are small, bean-shaped structures distributed throughout the body along the lymphatic vessels. They constitute an integral part of the lymphatic system and possess a distinctive structure, featuring the following elements: Capsule: Each lymph node is surrounded by a dense, fibrous connective tissue capsule. This capsule serves as a protective outer covering and provides…