1 / 39

Blood

Blood. Anatomy & Physiology. Functions of blood. Transportation Heat regulation. Composition of blood. Made of plasma & formed elements Plasma: fluid portion of blood Formed elements Red blood cells (erythrocytes) White blood cells (leukocytes) Platelets (thrombocytes).

maia
Download Presentation

Blood

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Blood Anatomy & Physiology

  2. Functions of blood • Transportation • Heat regulation

  3. Composition of blood • Made of plasma & formed elements • Plasma: fluid portion of blood • Formed elements • Red blood cells (erythrocytes) • White blood cells (leukocytes) • Platelets (thrombocytes)

  4. Watch US blood cells clip

  5. Hematocrit or Packed Cell Volume (PCV) • Percent of red blood cells in whole blood • Buffy coat (less than 1%): white blood cells & platelets

  6. Erythrocytes (RBCs) • Mature RBC has no nucleus, ribosomes, mitochondria • Small biconcave discs • Primary component: hemoglobin (1/3 of cell volume) • Flexible because of stretchable fibers called spectrin

  7. Function of RBCs • Transportation of oxygen & carbon dioxide depends on hemoglobin & an enzyme carbonic anhydrase

  8. Hemoglobin • 200-300 million molecules of hemoglobin in each RBC • Each hemoglobin molecule contains 4 protein chains called globin & each chain is bound to a red pigment, heme, which each heme contains an iron molecule • One hemoglobin molecule can unite with 4 oxygen molecules

  9. Erythropoiesis • Formation of RBC • Begins in the bone marrow from hematopoietic stem cells which form all blood cells • In series of steps lose nuclei to become reticulocyte which is released into circulation which become mature RBC which is smaller

  10. Erythropoietin • Hormone released by the kidney when blood oxygen levels decline which then stimulates the bone marrow to increase production of RBCs

  11. Destruction of RBCs • Life span of RBC is about 105-120 days • Macrophages in lining of blood vessels in spleen & liver phagocytose old or damaged RBC • Hemoglobin broken down & amino acids, iron & pigment bilirubin released • Iron used to form new hemoglobin & bilirubin transported to liver & excreted into the intestines in bile

  12. 5 types All have nuclei Larger than RBCs Granulocytes (have large granules in cytoplasm) Neutrophils Eosinophils Basophils Agranulocytes Lymphocytes Monocytes Leukocytes (WBCs)

  13. Neutrophils • About 65% of the total WBC count • Multilobed nucleus • Small light purple granules in cytoplasm • Function: cell defense by phagocytosis of microorganisms • Life span: hours to 3 days

  14. Eosinophils • Usually 2 lobed nucleus • Large orange-red staining granules • Function: cellular defense usually against parasites & involved in allergic reactions • Life span: 10-12 days

  15. Basophils • Usually 2 lobed nucleus • Sparse, large purple staining granules • Least numerous WBC • Function: secrete heparin & histamine • Life span: hours to 3 days

  16. Lymphocytes • Smallest of WBC, about 25% of total WBC count • Large spherical nuclei with scant pale blue cytoplasm • T-lymphocytes: directly attack infected or cancerous cell • B-lymphocytes: produce antibodies against specific antigens • Life span: days to years

  17. Monocytes • Largest of the WBC • Kidney bean shaped nuclei with large quantities of blue-gray cytoplasm • Phagocytic cell capable of ingesting bacteria, debris, cancerous cells • In tissue called macrophages • Life span: months

  18. WBC Formation • Neutrophils, eosinophils, basophils originate in bone marrow • Most lymphocytes & monocytes originate in lymphatic tissue

  19. Watch US platelets clip

  20. Platelets • Small, nearly colorless, irregular • 3 important physical properties • Agglutination • Adhesiveness • Aggregation

  21. Functions of platelets • Hemostasis: stoppage of blood flow • Damage to blood vesselsvascular spasm temporary platelet plug by sticky platelets secrete ADP, thromboxane & fatty acid (arachidonic acid) which are involved in coagulation • Coagulation: blood clotting

  22. Formation & Life Span of Platelets • Formed in bone marrow, lungs & spleen by fragmentation of very large cell, megakaryocyte • Life span: 7 days

  23. Watch US blood type clip

  24. Blood Types • Refers to the type of antigens, called agglutinogens, present on RBC membrane • Important blood antigens: A, B, Rh • Agglutinins: antibodies dissolved in plasma that react with specific blood group antigens

  25. ABO System • Type A: Antigen A on RBCs • Type B: Antigen B on RBCs • Type AB: Antigen A & B on RBCs • Type O: Neither A nor B on RBCs • Plasma never contains Ab against Ag present on it own RBCs • Plasma does contain AB against those Ag not present on its RBCs

  26. The Rh System • Rh positive: Rh antigen is present on RBCs • Rh negative: RBCs have no Rh antigen • Blood does not normally contain anti-Rh antibodies except thru previous transfusion or pregnancy

  27. Blood Plasma • 90% water, 10 % solutes • Most of the solutes are proteins (formed by liver) • Albumin: help maintain osmotic balance • Globulins: immune mechanism • Fibrinogen: blood clotting • Remaining solutes are food substances, metabolic products, respiratory gases, hormones, etc

  28. Four components critical to coagulation Prothrombin Thrombin Fibrinogen Fibrin Three stages Stage I Stage II Stage III Coagulation

  29. Stage I • Production of thromboplastin activator by either: • Extrinsic pathway: chemicals released from damaged tissues • Intrinsic pathway: chemicals present in the blood

  30. Stage II • Conversion of prothrombin to thrombin by the prothrombin activator produced in stage I

  31. Stage III • Conversion of fibrinogen to fibrin and production of fibrin clot by thrombin produced in Stage II

  32. Coagulation facts • Many of clotting factors require calcium ion as a cofactor • Liver synthesizes both prothrombin & fibrinogen. Vitamin K is necessary for production of prothrombin

  33. Conditions that oppose clotting • Smooth surface of lining of blood vessels does not allow platelets to stick • Antithrombins: substances in blood that oppose or inactivate thrombin • Ex: Heparin

  34. Conditions that hasten clotting • Rough spot in the blood vessel lining • Abnormally slow blood flow

  35. Clot Dissolution • Fibrinolysis: physiologic mechanism that dissolves clots

  36. Image Citations • Slide 5: Hematocrit, 12/20/06, http://www.drstandley.com/labvalues_hematology.shtml • Slide 13: Neutrophil, 12/27/06, http://faculty.une.edu/com/abell/histo/histolab3a.htm • Slide 14: Eosinophil, 12/27/06, http://faculty.une.edu/com/abell/histo/histolab3a.htm • Slide 14: eosinophil1a, 12/27/06, http://cellbio.utmb.edu/microanatomy/blood/more_eosinophils.htm • Slide 15: Basophils, 12/27/06, http://faculty.une.edu/com/abell/histo/histolab3a.htm • Slide 16: Medium lymphocyte, 12/27/06, http://www.anatomy.dal.ca/Human_Histology/Lab7/61LO4.html • Slide 17: Monocyte, 12/27/06, http://www.med-ed.virginia.edu/courses/path/innes/nh/wcbmaturation.cfm • Slide 21: Megakaryocyte, 12/30/06, http://www.med-ed.virginia.edu/courses/path/innes/nh/platelets.cfm

More Related