Anatomy and Physiology Lecture Notes - Blood PDF

JLAT,RMT ANATOMY AND PHYSIOLOGY LECTURE NOTES Prepared by: John Larry Amis Taberna, RMT TOPIC 6: Cardiovascular System (The Human Blood) Hematology – branch of science concerned with the s...

JLAT,RMT ANATOMY AND PHYSIOLOGY LECTURE NOTES Prepared by: John Larry Amis Taberna, RMT TOPIC 6: Cardiovascular System (The Human Blood) Hematology – branch of science concerned with the study of blood, blood-forming tissues, and the associated disorders Blood – liquid connective tissue that consists of cells surrounded by a liquid extracellular matrix (Plasma) Interstitial fluid – fluid that bathes body cells Functions: o Transport of gases (O2 and CO2), nutrients and waste products o Transport of processed molecules (Ex. transport of Vit. D) o Transport of regulatory molecules (hormones and enzymes) o Regulation of pH (normal: pH7.35–7.45) and osmosis (maintaining normal fluid and ion balance) o Maintenance of body temperature. o Protection against foreign substances o Clot formation Composition: o Plasma o Formed elements (RBC, WBC, Platelet) Total Blood Volume (Adult): o Male – 5-6L o Female – 4-5L Blood makes up about 8% of total body weight PLASMA JLAT,RMT  JLAT,RMT FORMED ELEMENTS Red Blood Cells (Erythrocyte) o Erythropoiesis: production of RBCs in red bone marrow o Erythropoietin(EPO): Hormone produced by kidney and responsible for RBC production. o Biconcave disk shape o Mature RBC: Non-nucleated o Life span: 120days (spleen “graveyard” of senescent RBCs) o Hemoglobin: primary protein that binds Oxygen and responsible for the cell’s red color o transport oxygen from the lungs to body cells and deliver carbon dioxide from body cells to the lungs o Hemoglobin ▪ consists of four globin (2alpha; 2beta) proteins and four heme groups (1:1 ratio) ▪ Each heme contains one iron atom, which is necessary for the normal function of hemoglobin ▪ Each iron in a heme molecule can reversibly bind to an oxygen molecule each globin can reversibly bind with carbon dioxide JLAT,RMT  JLAT,RMT ▪ 2/3 of body iron is in the hemoglobin ▪ Oxygenated blood: bright red ▪ Deoxygenated blood: dark red o Other molecules that binds to hemoglobin ▪ Carbon Monoxide gas produced by the incomplete combustion of hydrocarbons, such as gasoline has a higher affinity to hemoglobin than Oxygen result: Nausea, headache, unconsciousness, and death ▪ Carbon Dioxide produced in tissues and transported in the blood to the lungs, where it is removed from the blood Bicarbonate ions – major form of CO2 transported in blood Carbonic anhydrase o found primarily inside red blood cells o catalyzes a reaction that converts carbon dioxide (CO2) and water (H2O) into a hydrogen ion (H+) and a bicarbonate ion (HCO3−) RBC LIFE CYCLE Red Blood Cell and Erythropoietin Hypoxia – occur if too little oxygen enters the blood (causes: anemia, high altitudes, circulatory problems) o Hypoxia stimulates the kidneys to step up the release of erythropoietin to increase the production of RBCs JLAT,RMT  JLAT,RMT White Blood Cells (Leukocytes) o Nucleated and do not contain hemoglobin o Can be granular or agranular Granular Leukocyte ❖ Neutrophil o Aka Polymorphonuclear leukocytes (PMNs), polymorphs, polys or seggs o Diameter: 10-15 µm o Nucleus: 2 and 5 lobes o Cytoplasm: neutral staining o nucleus has two to five lobes connected by very thin strands of nuclear material o primary responder in bacterial infection o Primary granule: Myeloperoxidase ❖ Eosinophil o It neutralizes basophil and mast cell products o Kill parasites and responds to allergy o Diameter: 12-15 µm o Nucleus: bilobed or ellipsoidal and often eccentrically located o Cytoplasm: orange to reddish-orange ❖ Basophil o Contains Histamine granules that contracts smooth muscle and causes allergic reaction o Diameter: 10-15 µm o Cytoplasm: deep-bluish-purple o Primary Granules: Histamine Agranular Leukocyte ❖ Lymphocyte o increase in the number has diagnostic significance in acute viral infections and in some immunodeficiency diseases. ❖ Monocyte o Diameter: 12-22 µm o Nucleus: horse shoe shaped o Cytoplasm: dull grayish blue (“ground glass appearance”) o They migrate into tissues to be known as macrophages o Two types: Fixed and Wandering JLAT,RMT  JLAT,RMT Platelets (Thrombocyte) o Thrombopoietin – hormone that influences the production of platelet o Megakaryoblast – precursor cells for platelet production o Megakaryocyte – huge cells that splinter into 2000 to 3000 fragments (platelets) o Platelets break off from the megakaryocytes in red bone marrow and then enter the blood circulation o Platelets help stop blood loss from damaged blood vessels by forming a platelet plug o Lifespan: 5-9days (Aged and dead platelets are removed by fixed macrophages in the spleen and liver) o Hemostasis – a sequence of responses that stops bleeding and prevents hemorrhage ▪ Primary Hemostasis – formation of platelet plug ▪ Secondary Hemostasis – stabilization of platelet plug by serum proteins (clotting factors) ▪ Fibrinolysis – refers to the normal breakdown of clots. o Platelet Plug Formation ▪ Platelet adhesion platelets contact and stick to parts of a damaged blood vessel, such as collagen fibers of the connective tissue underlying the damaged endothelial cells ▪ Platelet Release Reaction Platelet is activated upon contact to collagen of damaged blood vessel and releases its contents o ADP and Thromboxane A2 – activate nearby platelets o Serotonin and Thromboxane A2 – causes vasoconstriction which decreases blood flow through the injured vessel JLAT,RMT  JLAT,RMT ▪ Platelet Aggregation ADP makes other platelets in the area sticky, and the stickiness of the newly recruited and activated platelets causes them to adhere to the originally activated platelets HEMATOPOIESIS/ HEMOPOIESIS Continuous, regulated process of renewal, proliferation, differentiation & maturation of all blood cells Embryonic o Mesoblastic Phase o Hepatic Phase o Myeloid Adult o Medullary (Bone marrow) o Extramedullary (Liver) MEDULLARY HEMATOPOIESIS Red Bone Marrow o primary site of hemopoiesis in the last 3 months before birth, and continues as the source of blood cells after birth and throughout life o highly vascularized connective tissue located in the microscopic spaces between trabeculae of spongy bone tissue o bones with active marrow: bones of the axial skeleton, pectoral and pelvic girdles, and the proximal epiphyses of the humerus and femur Pluripotent stem cell o derived from mesenchyme o Stem cells in red bone marrow that reproduce themselves, proliferate, and differentiate into cells that give rise to blood cells, macrophages, reticular cells, mast cells, and adipocytes o Reticular fibers – serves as framework that supports the cells of red bone marrow JLAT,RMT  JLAT,RMT Hemopoietic Growth Factors o Hormones that regulate the differentiation and proliferation of particular progenitor cells ▪ Erythropoietin (EPO) increases the number of red blood cell precursors produced primarily by cells in the kidneys in Renal Failure, EPO production is decreases ▪ Thrombopoietin (TPO) hormone produced by the liver stimulates the formation of platelets from megakaryocyte ▪ Cytokines produced by cells such as red bone marrow cells, leukocytes, macrophages, fibroblasts, and endothelial cells Colony Stimulating Factor and Interleukins o Two important families of cytokines that stimulate white blood cell formation JLAT,RMT  JLAT,RMT BLOOD GROUPS AND BLOOD TYPES Antigens – glycoproteins and glycolipids present in cell surface Blood groups – based on the presence or absence of various antigens in the red blood cell. Within a given blood group, there may be two or more different blood types. o Example: ABO Blood Group (Blood Types: Type A, B, AB, O) Common blood Group: ABO and Rh Blood Group ABO Blood Group based on two glycolipid antigens called A and B ABO antigens (agglutinogens) o Type A has only A antigen o Type B has only B antigen o Type AB has both A and B antigen o Type O do not have both A and B antigen ABO antibodies (agglutinins) o Present in the plasma that react with the A or B antigens if the two are mixed o anti-A antibody, which reacts with antigen A o anti-B antibody, which reacts with antigen B o an individual do not have antibodies that react with the antigens of theis own RBCs, but they have antibodies for any antigens that their RBCs lack Rh Blood Group named because the Rh antigen, called Rh factor, was first found in the blood of the Rhesus monkey Rh antigens are designated Rh+ (Rh positive); those who lack Rh antigens are designated Rh− (Rh negative). Important to consider in case of Hemolytic Disease of the Newborn (HDN) JLAT,RMT