Blood 1 - Lecture 20 PDF

blood 1 - lecture 20 Created @December 10, 2024 10:12 PM Class immunology blood and stem cells What is Blood? Blood consists of: Formed components: Red blood cells (RB...

blood 1 - lecture 20 Created @December 10, 2024 10:12 PM Class immunology blood and stem cells What is Blood? Blood consists of: Formed components: Red blood cells (RBCs). White blood cells (WBCs). Platelets. Dynamic component: Plasma (95% water). Contains plasma proteins, hormones, nutrients, waste products, and gases. Whole Blood = Plasma + Formed Components. Functions of Blood 1. Oxygen and Carbon Dioxide Transport: RBCs transport oxygen (primary role) and some carbon dioxide. 2. Transport of Substances: Plasma carries hormones, enzymes, nutrients, waste products (all water- soluble). 3. Clotting: Platelets initiate the process; they form the foundation for clot formation. 4. Immune Defense: WBCs defend against infections, each with specialized roles. blood 1 - lecture 20 1  5. Temperature Regulation: Blood vessels in the skin dilate or constrict to manage heat loss or retention. 6. pH Regulation: Maintains extracellular fluid pH at ~7.4, assisted by respiratory and renal systems. Historical Context of Blood Transfusion 1. Early Misunderstandings: 15th-century attempt: Pope Innocent VIII drank blood of young boys to gain vitality. All died. 2. 17th Century Milestones: William Harvey (1628): Discovered the circulatory system, proving blood is confined to vessels. Richard Lower (1665): First successful transfusion between dogs. Early human transfusions used animal blood but caused severe reactions. 3. First Human-to-Human Transfusion (1818): James Blundell: Transfused blood into a postpartum hemorrhage patient with successful recovery. Early transfusions were unpredictable; results varied widely. Revolution in Blood Transfusion 1. Discovery of Blood Types (1901): Karl Landsteiner: Identified the ABO blood typing system and later the Rhesus factor (1940). Understanding blood types allowed safer transfusion practices. 2. Technique Improvements (1913): blood 1 - lecture 20 2  Edward Lindemann: Introduced needle-based transfusion, enabling controlled volumes and separation of donor and recipient locations. Applications of Blood Transfusion Clinical Uses: Replace lost blood (e.g., hemorrhage, burns). Improve quality of life for terminally ill patients. Component-Specific Transfusions: RBCs: Treat anemia. Plasma: Aid burn victims. Platelets: Manage clotting disorders. Forensic and Identification Purposes: Criminal investigations and paternity cases rely on ABO and Rhesus systems. blood 1 - lecture 20 3