INTRODUCTION TO INTRODUCTION TO PLATELETSPLATELETS

developed bydeveloped by

Liz FracalanzaLiz Fracalanza

Tina GoodyearTina Goodyear

Hugh B. FackrellHugh B. Fackrell

Dept of Biological SciencesDept of Biological Sciences

University of WindsorUniversity of Windsor

Windsor, ON CanadaWindsor, ON Canada

OBJECTIVESOBJECTIVES

To examine the formed To examine the formed elements of bloodelements of blood

To define the structure and To define the structure and function of the cellular function of the cellular elements elements

To differentiate between To differentiate between the various blood cells the various blood cells

IntroductionIntroduction

Blood may be separated Blood may be separated into a clear fluid into a clear fluid composed of either serum composed of either serum or plasma and formed or plasma and formed elements which contain elements which contain cells and cell fragmentscells and cell fragments

Formed Elements of BloodFormed Elements of Blood

Thrombocytes (plateletsThrombocytes (platelets))Erythrocytes (red blood cells)Erythrocytes (red blood cells)Leucocytes (white blood cells)Leucocytes (white blood cells)

Prepartion of BloodPrepartion of Blood

Prevent coagulation by the addition of an Prevent coagulation by the addition of an anticoagulantanticoagulant

Smear blood onto a glass slide, stain and Smear blood onto a glass slide, stain and examine under a microscopeexamine under a microscope

Use an oil immersion or a high-dry Use an oil immersion or a high-dry objectiveobjective

Use an area of the slide with little red Use an area of the slide with little red cell overlapcell overlap

PLATELETSPLATELETS

Platelet CharacteristicsPlatelet Characteristics

Diameter :2.9 - 4.3 umDiameter :2.9 - 4.3 umThickness :0.7 - 1.1 umThickness :0.7 - 1.1 umCytoplasm :purple/blue-greyCytoplasm :purple/blue-greyNucleus :noneNucleus :noneLife-span :8 - 12 daysLife-span :8 - 12 daysGranules :Present(not visible)Granules :Present(not visible)

Platelet FunctionPlatelet Function

Maintain blood vessel integrity Maintain blood vessel integrity Prevent blood loss to maintain Prevent blood loss to maintain hemostasishemostasis

Synthesize chemical substancesSynthesize chemical substances provide a reaction surface for provide a reaction surface for the coagulation cascade the coagulation cascade

AntibodyAntibody - A specific immunoglobulin - A specific immunoglobulin (protein) produced by plasma cells (protein) produced by plasma cells or B cells in response to a foreign or B cells in response to a foreign particle.particle.

AnticoagulantAnticoagulant - A substance that - A substance that inhibits blood clotting.inhibits blood clotting.

BasophilicBasophilic - To have an affinity for - To have an affinity for basic dyes such as methylene blue basic dyes such as methylene blue used in the Wright stain.used in the Wright stain.

ChemotaxisChemotaxis - A chemical - A chemical stimulation causing the movement stimulation causing the movement of a om the chemical source. It of a om the chemical source. It is a part of the inflammation is a part of the inflammation response.response.

ChromatinChromatin - The stainable - The stainable material of the cell nucleus material of the cell nucleus composed of basic histones, composed of basic histones, condensed nucleoprotein and condensed nucleoprotein and parachromatinparachromatin

CoagulationCoagulation - The series of chemical - The series of chemical reactions that result in blood reactions that result in blood clotting.clotting.

ComplementComplement - Serum proteins that - Serum proteins that participate in an enzymatic participate in an enzymatic cascade, resulting in a cytolytic cascade, resulting in a cytolytic membrane attack complex.membrane attack complex.

Endothelial LiningEndothelial Lining - A layer of - A layer of cells that line the blood and cells that line the blood and lymphatic vessels.lymphatic vessels.

HemostasisHemostasis - An equilibrium of - An equilibrium of blood cells and plasma required blood cells and plasma required to support life (homeostasis). to support life (homeostasis).

HeparinHeparin - An anticoagulant used to - An anticoagulant used to inhibit the coagulation cascade by inhibit the coagulation cascade by enhancing the activity of anti-enhancing the activity of anti-thrombin III. thrombin III.

HistamineHistamine - A vasoactive amine - A vasoactive amine secreted by the blood basophils and secreted by the blood basophils and mast cells when stimulated by IgE mast cells when stimulated by IgE antibodies.antibodies.

LymphokineLymphokine - A protein released by - A protein released by lymphocytes that acts as a cellular lymphocytes that acts as a cellular mediator in the immune response.mediator in the immune response.