Blood Lecture Outline : Fluid Connective Tissue Part I of the Cardiovascular Unit

Transcription

1 Blood Lecture Outline : Fluid Connective Tissue Part I of the Cardiovascular Unit General Characteristics: Extracellular matrix ph Volume Functions of the blood: 1. Transport 2. Regulation 3. Protection Composition of Blood (hematocrit): Typical concentration is 4-6 million per cubic mm (or hematocrit [packed cell volume] of about 42% for females & 45% for males) Puncture and Collection: Measure the distance of total fluid and the distance of RBC and divide = %

2 PART 1: FORMED ELEMENTS A) Erythrocytes (4-6 million/mm 3: Anucleate (so can t repro, die after ~ 120 days) biocancave What is so advantageous of the shape? Structure = function transport hemoglobin (each RBC has about 280 million hemoglobin molecules) contain carbonic anhydrase (critical for transport of carbon dioxide) RBC Life Cycle (role of erythropoietin ) Erythropoiesis = formation of erythrocytes wblood.html - make 2.5 million new RBCs per sec -bone marrow (adult = flat bones) - begins with a cell called a hemocytoblast or stem cell (below) - rate is regulated by oxygen levels: hypoxia (lower than normal oxygen levels) is detected by cells in the kidneys o o via the hypothalamus kidney cells release the hormone erythropoietin into the blood erythropoietin stimulates erythropoiesis by the bone marrow Bone Marrow Smear and talk :

3 Hemoglobin : normal range of g Hb/100 ml of whole blood composed of globin (made up of 4 highly folded polypeptides)+ 4 heme groups (with iron) each molecule can carry 4 molecules of oxygen called oxyhemoglobin when carrying oxygen & called reduced hemoglobin when not can also combine with carbon dioxide & helps transport carbon dioxide Increase RBC = increase viscosity SICKLE CELL: B chain has valine substitute:

4 The binding and release of oxygen illustrates the structural difference between oxyhemoglobin and reduced (or deoxy-) hemoglobin. Only o of the four heme groups is shown (Source: wikipedia). What give Hb color? Hemoglobin recycling PART B Platelets = Thrombocytes 250, ,000/mm 3 : ( thrombopoietin hormone) 2-4 micrometers Megakaryocytes Video Live for 5 9 days Sacs full of fibrin Form Platelets: video 1 - formed in the bone marrow from cells called megakaryocytes 2 - have no nucleus, but can secrete a variety of substances & can also contract (because they contain actin & myosin) 3 - normal concentration in the blood is about 250,000 per cubic millimeter 4 - remain functional for about 7-10 days (after which they are removed from the blood by macrophages in the spleen & liver) 5- play an important role in hemostasis (preventing blood loss)

5 PART C Leukocytes 5,000-9,000/ mm3 Leukocytes: (role of CSF: colony stimulating hormone) How WBC are formed: types of WBCs: Agranulocytes: (2-8%) Monocytes dk purple nucleus (25-40%)Lymphocytes dk purple nucleus

6 Granulocytes Eosinophils (1-4%) red cytoplasm/blue nucleus E: help initiate and sustain inflammation and can activate T-cells (directly by serving as antigen-presenting cells and indirectly by secreting a variety of cytokines. Eosinophils can also kill bacteria by quickly releasing mitochondrial DNA and proteins Basophils (less than 1%) blue cytoplasm/dk blue nucleus U: along with mast cells, play a role in inflammation and allergic responses Neutrophils: 50-70% of WBCs: pink cytoplasm/purple nucleus multi lobed: phagocytosis (bacteria & cellular debris); very important in inflammation Diapedesis - Eosinophils respond to diverse stimuli, including tissue injury, infections,, allergens, and tumors. release a variety of cytokines, chemokines, lipid mediators, and neuromodulatorsdirectly communicate with T cells and mast cells.

7 Release of histamine (that contributes to the 'symptoms' of allergies) by mast cells requires the production of antibodies (IgE) by B-cells and that process is regulated, in part, by cytokines produced by basophils (Bischoff 2007). Monocytes - phagocytosis (typically as macrophages in tissues of the liver, spleen, lungs, & lymph nodes) & also important antigen-presenting cells

8 Once distributed through the blood stream, monocytes enter other tissues of the body such as the liver (Kupffer cells), lungs (alveolar macrophages), skin (Langerhans cells), and central nervous system (microglia) (Gordon 2003). Lymphocytes - immune response (including production of antibodies) Eosinophils (in green with red nucleus) catapult their mitochondrial DNA out of the cell, forming tangled traps (red) that ensnare foreign bacteria. (Photo credit: Hans-Uwe Simon, Institute of Pharmacology, University of Bern, Switzerland) Some important characteristics of White Blood Cells (particularly neutrophils): 1 - phagocytic 2 - capable of diapedesis (also called extravasation)

9 3 - capable of ameboid movement 4 - exhibit chemotaxis (attracted to certain chemicals, such as those released by damaged cells) 3. Plasma formation PLASMA FORMATION: Acidosis alkalosis Plasma proteins: (albumin, fibrinogen, globulins) hepatocytes: albumins: globulins: fibrinogens: 5.Homeostasis = hemostasis 3 phases = vascular spasm,à platelet plug à coagulation Cascade Coagulation video :

10 6. Blood typing Agglutination Antigens = agglutinogens Antibodies = agglutinins ABO Rh system 7. Blood tests: know how to perform these, read then and interpret Blood typing Taliquist Sedimation rate Hematocrit : look for interactive

11 Clotting WBC differential count Leucopenia Leukocytosis 8. Blood disorders Disorders of hemostasis Thrombus Embolus Blood clotting Serotonin = vascular spasm + tissue thromboplastin + prothrombin/ca++ =thrombin + fibrinogen = fibrin = clot *thrombus & embolus = L Anemia How to diagnose? Anemia from RBC loss:

12 Polycythemia Bleeding Disorders Thrombocytopenia Hemophilia Low cf Types of Anemias a. decrease in RBC number b. inadequate Hb in RBC c. Abnormal Hb in RBC 9. Liver and jaundice Cord Blood: How to make a blood Slide:

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