Lecture 16: Blood Cells and Coagulation (PDF)

About This Chapter 16.1 Plasma and the Cellular Elements of Blood 16.2 Blood Cell Production 16.3 Red Blood Cells 16.5 Hemostasis and Coagulation Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 16.1 Plasma and the Cellular Elements of Blood • Plasma is extracellular matr...

About This Chapter 16.1 Plasma and the Cellular Elements of Blood 16.2 Blood Cell Production 16.3 Red Blood Cells 16.5 Hemostasis and Coagulation Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 16.1 Plasma and the Cellular Elements of Blood • Plasma is extracellular matrix • Fluid matrix of blood – Water (~ 92%) – Proteins (~ 7%) – Remaining 1% ▪ Ions (Na+ , K + , Cl- , H+ , Ca2+ , & HCO3 - ) ▪ Organic molecules ▪ Gases (O2 & CO2 ) ▪ Trace elements ▪ Vitamins Some globulins, like immunoglobulins synthesized and secreted by specialized blood cells rather than by liver • Identical in composition to interstitial fluid but has plasma proteins clotting protein iron-transporting protein – Albumins, globulins, fibrinogen, transferrin 60% Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Cellular Elements Include RBCs, WBCs, and Platelets • Red blood cells (RBCs) – also called erythrocytes have lost nuclei thrombocytes • nucleus, cell fragments that have split off a relatively Platelets – split off from megakaryocytes lack large parent cell megakaryocyte • White blood cells (WBCs) – also called leukocytes only fully functional cells in circulation 1) Lymphocytes – also called immunocytes specific immune responses ingest foreign particles such as bct 2) Monocytes – develop into macrophages; phagocytes bc (phagocytosis) 3) Neutrophils – phagocytes and granulocytes 4) Eosinophils – granulocytes bc contain cytoplasmic inclusions = granular appearance 5) Basophils – granulocytes; tissue basophils are called mast cells Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.1 Composition of blood (1 of 2) Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.1 Composition of blood (2 of 2) Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 16.2 Blood Cell Production (1 of 2) • Blood cells are produced in the bone marrow – Hematopoiesis: production of blood cells – Red bone marrow is red because it contains hemoglobin; active ▪ – • oxygen binding protein of RBC 25% RBCS, 75% WBCs Yellow bone marrow contains adipose cells; inactive released from 1 cell that affect growth or Hematopoiesis is controlled by cytokines peptides/proteins activity of another cell Interleukins: IL-3 —> released by 1 WBC to act on another one called factors = growth factor, differentiating factor, trophic (nourishing) factor… Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.2 Hematopoiesis Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 16.2 Blood Cell Production (2 of 2) molecules made by endothelial cells and WBC = cytokine • • Colony stimulating factors regulate leukopoiesis – CSFs – Leukopoiesis: production of white blood cells cytokine Thrombopoietin regulates platelet production – • regulates growth and maturation of megakaryocytic TPO produced primarily in liver Erythopoietin regulates red blood cell production – EPO – Erythropoiesis: production of red blood cells cytokine made primarily in kidneys of adults Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Table 16.1 Cytokines Involved in Hematopoiesis Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.3 The Complete Blood Count (1 of 3) A complete blood count, commonly known as a CBC, provides the information in the table below. The numbers shown are the normal ranges of values. In addition, a CBC usually also includes the following information: • Mean corpuscular volume (MCV): the average volume of one red blood cell. A corpuscle is a small unattached cell (diminutive of corpus, body) • Mean corpuscular hemoglobin (MCH): amount of hemoglobin per RBC • Mean corpuscular hemoglobin concentration (MCH C): the amount of hemoglobin per volume of one red blood cell Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.3 The Complete Blood Count (2 of 3) Blood Count Normal Ranges of Values Test Hematocrit Hematocrit is the percentage of total blood volume that is occupied by packed (centrifuged) red blood cells. Hemoglobin (g Hb/dL* whole blood) The hemoglobin value reflects the oxygen-carrying capacity of red blood cells. (dL = deciliter = 100 mL) Red Cell Count (cells/mL) A machine counts erythrocytes as they stream through a beam of light. Total White Count (cells/mL) A total white cell count includes all types of leukocytes but does not distinguish between them. Males Females 40–54% 37–47% 14–17 12–16 4.5 − 6.5×106 3.9 − 5.6×106 4 − 11×103 4 − 11×103 Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 16.3 Red Blood Cells • Hematocrit: ratio of red blood cells to plasma, expressed as a percentage RBC/total blood volume • Mature RBCs lack a nucleus – Morphology can provide clues to the presence of disease – Mean corpuscular volume (MCV): size of red blood cells Cells losing their flattened disk shape and become spherical (spherocytosis), shape similar to that of the cell in hypotonic medium: disease Sickle cell anemia, cells are shaped like a sickle or crescent moon Some diseases: size of RBC = MCV —> abnormally large or small (microcytic iron deficiency anemia) If pale due to lack of red Hb: hypochromic Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.4(a-b) Bone Marrow Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Hemoglobin Synthesis Requires Iron • Hemoglobin plays a role in oxygen transport • Four globin molecules • – Four heme groups – Several isoforms Heme is a porphyrin ring with an iron (Fe) atom at its center – Iron comes from diet – Transported in blood by transferrin – Iron taken up in bone marrow – Excess iron stored in liver by ferritin Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved RBCs Live about Four Months • • • Live for about 120 days – Older RBCs rupture or phagocytized in spleen – Amino acids from globin are incorporated into new proteins – Some iron from heme groups are reused in new heme groups Remnants of heme groups are converted to bilirubin, excreted as bile – Bilirubin metabolites are excreted in urine – Jaundice results from elevated levels of bilirubin RBC disorders decrease oxygen transport – Anemia: hemoglobin content is too low ▪ rate of RBC destruction > production genetic defect in which glutamate is replaced by valine —> abnormal Hb that crystallizes when it gives up its oxygen —> sickle form that gets tangled with others —> block blood flow to tissues — > tissue damage and pain from hypoxia Hemolytic anemia (example hereditary spherocytosis), sickle cell disease, not enough iron to make heme erythrocyte cytoskeleton does not link properly bc of iron-deficiency anemia groups —> Hb synthesis defective or deficient cytoskeletal proteins, so cells slower stem cell dysfunction that produces too ▪ blood cells —> blood more Polycythemia vera many viscous and more resistant to flow through circulatory system are more like spheres than biconcave disks —> RBC ruptures easily and are unable to withstand osmotic changes like normal cells Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.6(a-b) Hemoglobin Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.6(c) Hemoglobin Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved 16.5 Hemostasis and Coagulation • Hemostasis prevents blood loss from damaged vessels – Vasoconstriction – Platelet plug begins with platelet adhesion – Exposed collagen and tissue factor lead to a clot ▪ Coagulation cascade – Thrombus blood clot that adheres to the undamaged wall of blood vessel when too much clotting • Platelet activation begins the clotting process – Platelets stick to collagen in damaged vessels platelet membrane phospholipids into – Release of platelet-activating factor (PAF) → thromboxane A2 vasocontrictors intact vascular endothelial cells convert their membrane lipid into it (eicosanoid) that blocks platelets – Prostacyclin adhesion and aggregation Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.8 Hemostasis and tissue repair Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.9 Platelet plug formation Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Coagulation Converts a Platelet Plug into a Clot begins when damage to the tissue exposes collagen • protein already present in plasma Two pathways uses collagen activates 1st enzyme: factor XII to begin cascade – Intrinsic pathway known as contact activation pathway starts when damaged tissues expose factor III – Extrinsic pathway known as cell injury pathway tissue activates factor VII • Common pathway 2 pathways unite at this pathway to create thrombin – Thrombin converts fibrinogen into insoluble fibrin polymers – Fibrin fibers become part of the clot • Fibrin broken by the enzyme plasmin into fragments – Inactive plasminogen activated to plasmin by tissue Plasminogen: inactive form of plasmin, in clot coagulation, thrombin, a factor in coagulation cascade, works with plasminogen activator (tPA) After 2nd factor called tPA to convert inactive plasminogen —> plasmin • Fibrinolysis by plasmin that break down fibrin Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.10 The coagulation cascade Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Figure 16.11 Coagulation and fibrinolysis Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved Key words: plasma, plasma proteins, albumins, globulins, fibrinogen, hemoglobin, erythropoiesis, erythropoietin (EPO), hypoxia, hypoxia-inducible factor 1 (HIF-1), hematocrit, bilirubin, bile, hemostasis, hemorrhage, coagulation, platelet plug, platelet adhesion, platelet aggregation, tissue factor, clot, coagulation cascade, fibrin, plasmin, thrombus, intrinsic pathway, contact activation pathway, extrinsic pathway, tissue thromboplastin, common pathway, thrombin, fibrinogen, fibrin, plasmin, plasminogen, tissue plasminogen activator (tPA), fibrinolysis. Copyright © 2019, 2016, 2013 Pearson Education, Inc. All Rights Reserved