BLOOD FORMATION AND COMPOSITION PRESENTED BY LISA CHADHA MSC MSC NURSING FY STD BVCON

BLOODProvides a mechanism for rapid transport of nutrients, waste products, respiratory gases and cellsPowered by the pumping action of the heart

Introduction

Cardiovascular SystemSystem made up of blood vessels, blood and heart. Major function is to transport nutrients, gases and hormones to the cells and pick up wastes from cells to transport them to areas of body where they are excretedLymphatic SystemNetwork of vessels that return the fluid escaped from blood vessels back to the bloodstreamIncludes lymphocytes, lymphoid tissue and lymphoid organs which fight infections and give immunity to disease Circulatory System Together the cardiovascular system and lymphatic system make up the circulatory system

COLOUR SCARLET RED VOLUME- NORMAL ADULT 5 LITRES REACTION AND PH- SLIGHTLY ALKALINE AND PH 7.4SPECIFIC GRAVITY- 1.052-1.061VISCOSITY- 5 TIMES MORE VISCOUS THAN WATER PROPERTIES OF BLOOD

FUNCTIONS OF BLOODTransportation - the blood transports dissolved gases, nutrients, hormones and metabolic wastes.Protection - the blood restricts fluid losses through damaged vessels. Platelets in the blood and clotting proteins minimize blood loss when a blood vessel is damaged.RegulationBlood regulates the pH and electrolyte composition of the interstitial fluids. Blood regulates body temperature.

COMPOSITION OF BLOOD

Males: 5 6 liters Females: 4 5 liters

55% PLASMA45% CELLULAR

COMPONENTS

BLOOD PLASMAStraw-colored, sticky fluid portion of bloodApproximately 90% waterContains: Ions Na+ and Cl- Nutrients sugars, amino acids, lipids, cholesterol, vitamins and trace elements Three main proteins - Albumin (60%), globulin (35%), fibrinogen (4%) Dissolved Gasses including O2 and CO2 Waste Products other protein wastes such as urea and bilirubin

Figure 19.1cComposition of Whole Blood

Wrights StainFigure 17.2b

FORMED ELEMENTSRed blood cells (erythrocytes)White blood cells (leukocytes)GranulocytesNeutrophilsEosinophilsBasophilsAgranulocytes LymphocytesMonocytesPlatelets (thrombocytes)

Erythrocytes Red Blood Cells (RBCs)Oxygen-transporting cells 7.5 m in diameter (diameter of capillary 8 10m)Most numerous of the formed elements Females: 4.3 5.2 million cells/cubic millimeter Males: 5.2 5.8 million cells/cubic millimeterMade in the red bone marrow in long bones, cranial bones, ribs, sternum, and vertebraeAverage lifespan 100 120 days

RBC Structure And FunctionHave no organelles or nuclei Hemoglobin oxygen carrying protein Each RBC has about 280 million hemoglobin moleculesBiconcave shape 30% more surface area

Leukocytes White Blood Cells (WBCs)Protect the body from infectious microorganisms4,800 11,000/cubic millimeterFunction outside the bloodstream in loose connective tissue Diapedesis circulating leukocytes leave the capillariesWBCs have a nucleus and are larger than RBCsMost produced in bone marrow Lifespan of 12 hours to several years

Leukocytes White Blood Cells (WBCs)Two types of leukocytesGranulocytesAgranulocytesDifferential WBC CountNeverLetMonkeysEatBananas

Figure 17.5

White Blood Cells

Type Of White Blood Cells% By Volume Of WBCDescriptionFunctionNeutrophils60 70 %Nucleus has many interconnected lobes; blue granulesPhagocytize and destory bacteria; most numerous WBCEosinophils2 4 %Nucleus has bilobed nuclei; red or yellow granules containing digestive enzymesPlay a role in ending allergic reactionsBasophils< 1 %Bilobed nuclei hidden by large purple granules full of chemical mediators of inflammationFunction in inflammation medication; similar in function to mast cells Lymphocytes (B Cells and T Cells)20 25 %Dense, purple staining, round nucleus; little cytoplasmthe most important cells of the immune system; effective in fighting infectious organisms; act against a specific foreign molecule (antigen)Monocytes4 8 % Largest leukocyte; kidney shaped nucleusTransform into macrophages; phagocytic cells

GranulocytesNeutrophils most numerous WBCPhagocytize and destroy bacteriaNucleus has two to six lobesGranules pick up acidic and basic stains

Figure 17.4a

Eosinophils compose 1 4% of all WBCsPlay roles in ending allergic reactions, parasitic infections

Figure 17.4bGranulocytes

GranulocytesBasophils about 0.5% of all leukocytesNucleus usually two lobesGranules secrete histamines Function in inflammation mediation, similar in function to mast cells

AgranulocytesLymphocytes compose 20 45% of WBCsThe most important cells of the immune systemNucleus stains dark purpleEffective in fighting infectious organismsAct against a specific foreign molecule (antigen)Two main classes of lymphocyte T cells attack foreign cells directlyB cells multiply to become plasma cells that secrete antibodies

Figure 17.4d

AgranulocytesMonocytes compose 48% of WBCsThe largest leukocytesNucleus kidney shapedTransform into macrophagesPhagocytic cells

Figure 17.4e

LymphocytesT lymphocytes can attack foreign cells directly

Lymphocytes B lymphocytes transform into plasma cells and secrete antibodies

Summary of Formed ElementsTable 17.1

PLATELETS StructureSmall cellular fragments; originate in bone marrow from giant cell megakaryocyteContain several clotting factors calcium ions, ADP, serotoninFunctionInvolved in stopping bleeding when a blood vessel is damaged; Process is called hemostasis

Production of Formed ElementsHematopoiesis or hemopoiesis: Process of blood cell productionStem cells: All formed elements derived from single populationProerythroblasts: Develop into red blood cellsMyeloblasts: Develop into basophils, neutrophils, eosinophilsLymphoblasts: Develop into lymphocytesMonoblasts: Develop into monocytesMegakaryoblasts: Develop into platelets

Blood Cell FormationHematopoiesis process by which blood cells are formed100 billion new blood cells formed each dayTakes place in the red bone marrow of the humerus, femur, sternum, ribs, vertebra and pelvisRed marrow actively generates new blood cellsContains immature erythrocytesRemains in epiphyses, girdles, and axial skeletonYellow marrow dormant Contains many fat cellsLocated in the long bones of adultsTissue framework for red marrowReticular connective tissue

Cell Lines in Blood Cell FormationGenesis of erythrocytesCommitted cells are proerythroblasts Remain in the reticulocyte stage for 12 days in circulationMake up about 12% of all erythrocytesFormation of leukocytesGranulocytes form from myeloblasts Monoblasts enlarge and form monocytesPlatelet-forming cells from megakaryoblasts, break apart into platelets

The Blood Throughout LifeFirst blood cells develop with the earliest blood vesselsMesenchyme cells cluster into blood islands Late in the second month the liver and spleen take over blood formationBone marrow becomes major hematopoietic organ at month 7

RBC life span and circulation Replaced at a rate of approximately 3 million new blood cells entering the circulation per secondDamaged or dead RBCs are recycled by phagocytes Components of hemoglobin individually recycledHeme stripped of iron and converted to biliverdin, then bilirubinIron is recycled by being stored in phagocytes, or transported throughout the blood stream bound to transferrin

Figure 19.5Red Blood Cell Turnover

COMPOSITION OF BLOODNORMAL VALUES

WBC, Total.............(4000/L -11000/L)RBC, Total......M(4.5 - 6.5)m/L, F(3.85.8)m/L.Hemoglobin... M(13.0-18.0)g/dL F(11.6-16.5)g/dLHCT......................... M(40 - 54)% F(38 - 47)%MCV..................... (80 - 90)fLMCH....................... (27 - 32)pgMCHC..................... (33 - 38)g/dLPlatelet Count....................(150,000-400,000)/L