Blood and HaemoBlood and Haemopoiesispoiesis

Overview of BloodOverview of Blood

Blood is a fluid Blood is a fluid connective tissue.connective tissue.

Its total volume is Its total volume is about 6 liters.about 6 liters.

It has many It has many functions.functions.

Blood is made of Blood is made of two parts: blood two parts: blood cells and plasma. cells and plasma.

Main FunctionsMain Functions

Transport of nutrients and oxygen to cells.Transport of nutrients and oxygen to cells. Transport of wastes and carbon dioxide awaTransport of wastes and carbon dioxide awa

y from cells.y from cells. Delivery of hormones and other regulatory sDelivery of hormones and other regulatory s

ubstances to and from cells and tissues.ubstances to and from cells and tissues. Maintenance of homeostasis.Maintenance of homeostasis. Transport of humoral agent and cells of the Transport of humoral agent and cells of the

immune system. immune system.

PlasmaPlasma

Acellular fluid in which blood cells are suspendAcellular fluid in which blood cells are suspended ed

Its main component is water.Its main component is water. A variety of solutes ,including A variety of solutes ,including proteinsproteins (albumi (albumi

n, fibrinogen) , n, fibrinogen) , dissolved gasesdissolved gases (oxygen, carbo (oxygen, carbon dioxide) , n dioxide) , electrolyteselectrolytes (Na, Mg ,Ca), (Na, Mg ,Ca), nutrientsnutrients (glucose, lipids) , (glucose, lipids) , regulatory substancesregulatory substances (horm (hormones, enzymes) and ones, enzymes) and waste materialswaste materials (drugs ure(drugs urea).a).

What do blood cells include?What do blood cells include?

Platelets Platelets

ErythrocytesErythrocytes

LeukocytesLeukocytes

neutrophilsneutrophilsgranulocytesgranulocytes

eosinophilseosinophils

lymphocyteslymphocytes agranulocytesagranulocytes

basophilsbasophils

monocytesmonocytes

ErythrocytesErythrocytes 4.4-5×4.4-5×10101212 / L (F) / L (F) 5×5×10101212 / L (M) / L (M)

Anucleate, biconcavAnucleate, biconcave disks.e disks.

Quite flexible.Quite flexible. Packed with protein Packed with protein

hemoglobin (110-16hemoglobin (110-160g/L).0g/L).

Few reticulocytes.Few reticulocytes.

Membrane proteinsMembrane proteins

Integral membrane proIntegral membrane proteins: express blood grteins: express blood group antigens, attach cyoup antigens, attach cytoskeletal protein netwtoskeletal protein network to the cell membraork to the cell membrane. ne.

Peripheral membrane Peripheral membrane proteins: organized intproteins: organized into cytoskeletal protein no cytoskeletal protein network. etwork.

LeukocytesLeukocytes 4~10×4~10×101099 / L / L

Possess two types of granules: specific granPossess two types of granules: specific granules and azurophilic granules.ules and azurophilic granules.

Granulocytes have nuclei with two or more lGranulocytes have nuclei with two or more lobes. obes.

Include the neutrophils, eosinophils, and baInclude the neutrophils, eosinophils, and basophils. sophils.

Involved in body’s cellular and humoral deInvolved in body’s cellular and humoral defense against foreign material. fense against foreign material.

Granulocytes

NeutrophilsNeutrophils 50~70%50~70%

Spherical, with a nucleus consisting of tSpherical, with a nucleus consisting of two to five lobes.wo to five lobes.

The active phagocytes of bacteria and otThe active phagocytes of bacteria and other foreign agents.her foreign agents.

Specific granules: collagenase, phospholSpecific granules: collagenase, phospholipaseipase

Azurophilic granules: myeloperoxidase Azurophilic granules: myeloperoxidase (kill bacteria) , acid hydrolases and defe(kill bacteria) , acid hydrolases and defensin (digest foreign agents)nsin (digest foreign agents)

Tertiary granules: phosphatases , gelatinTertiary granules: phosphatases , gelatinases and collagenases.ases and collagenases.

EosinophilsEosinophils 0.5~3%0.5~3%

Nuclei are bilobed.Nuclei are bilobed. Large and elongated refLarge and elongated ref

ractile specific granules.ractile specific granules. Associated with allergic Associated with allergic

reactions, parasitic infereactions, parasitic infections.ctions.

EosinophilsEosinophils

Specific granules: major basic protein (MBP), eSpecific granules: major basic protein (MBP), eosinophil cationic protein(ECP), eosinophil perosinophil cationic protein(ECP), eosinophil peroxidase(EPO) and eosinophil-derived neurotoxoxidase(EPO) and eosinophil-derived neurotoxin (EDN);in (EDN);

----destruct parasites----destruct parasites.. histaminase, arylsulfatase, collagenase.histaminase, arylsulfatase, collagenase. ----attenuate allergic reactions----attenuate allergic reactions. . Azurophilic granules: acid hydrolases.Azurophilic granules: acid hydrolases. ----attenuate allergic reactions----attenuate allergic reactions..

BasophilsBasophils 0~1%0~1%

Nucleus is divided into irregNucleus is divided into irregular lobes.ular lobes.

Specific granules are few aSpecific granules are few and irregular in size and shand irregular in size and shape. Contain heparan sulfate,pe. Contain heparan sulfate, histamine, and slow-reacti histamine, and slow-reacting substance of anaphylaxing substance of anaphylaxis (SAS-A). s (SAS-A).

Participate in anaphylaxis, Participate in anaphylaxis, anticoagulation. anticoagulation.

Leukocytes-agranulocytesLeukocytes-agranulocytes

Do not have specific granules, but contaiDo not have specific granules, but contain azurophilic granules.n azurophilic granules.

The nucleus is round or indented.The nucleus is round or indented. Includes lymphocytes and monocytes.Includes lymphocytes and monocytes.

LymphocytesLymphocytes 20~30%20~30%

The spherical cell has a The spherical cell has a spherical nucleus with spherical nucleus with an indentation.an indentation.

The cytoplasm is scanty.The cytoplasm is scanty. All related to immune All related to immune

reactions.reactions.

MonocytesMonocytes 3~8%3~8%

The largest cells of thThe largest cells of the leukocytes.e leukocytes.

The nucleus is oval, eThe nucleus is oval, eccentrically placed.ccentrically placed.

Precursors of the cellPrecursors of the cells of the mononuclear s of the mononuclear phagocytotic system.phagocytotic system.

PlateletsPlatelets 100~400×100~400×101099 / L / L

Nonnucleated 2-4 um, Nonnucleated 2-4 um, cytoplasmic fragmentcytoplasmic fragments derived from megaks derived from megakaryocytes.aryocytes.

Promote blood clottinPromote blood clotting and help repair gaps g and help repair gaps in the walls of blood vin the walls of blood vessels.essels.

Each platelet has a peripheral light Each platelet has a peripheral light blue-stained transparent zone, the blue-stained transparent zone, the hyalomerehyalomere and a central zone and a central zone containing purple granules, called containing purple granules, called the the granulomere.granulomere.

cell coat rich in glycosaminoglycans cell coat rich in glycosaminoglycans and glycoproteins involved in and glycoproteins involved in platelets adhesion.platelets adhesion.

HaemopoiesisHaemopoiesis Hemopoiesis includes both erythropoiesHemopoiesis includes both erythropoies

is and leukopoiesis, as well as thrombopis and leukopoiesis, as well as thrombopoiesis.oiesis.

In the adult, erythrocytes,granulocytes, In the adult, erythrocytes,granulocytes, monocytes, and platelets are formed in tmonocytes, and platelets are formed in the red bone marrow; lymphocytes are alhe red bone marrow; lymphocytes are also formed in the red bone marrow and iso formed in the red bone marrow and in the lymphatic tissues.n the lymphatic tissues.

Hematopoiesis is therefore the result Hematopoiesis is therefore the result of simultaneous, continuous of simultaneous, continuous proliferation and differentiation of proliferation and differentiation of cells derived from steam cells.cells derived from steam cells.

Monophyletic theoryMonophyletic theory

Pluripotential stem cell (PPSC) differentiate intPluripotential stem cell (PPSC) differentiate into multipotential myeloid stem cell and multipo multipotential myeloid stem cell and multipotential lymphoid stem cell.otential lymphoid stem cell.

Multipotential myeloid stem cell only in bone Multipotential myeloid stem cell only in bone marrow and give rise to all blood cells other thmarrow and give rise to all blood cells other than lymphocytes.an lymphocytes.

Multipotential lymphoid stem cell in bone marMultipotential lymphoid stem cell in bone marrow and in lymphoid tissues ,give rise to lymphrow and in lymphoid tissues ,give rise to lymphocytes.ocytes.

Bone MarrowBone Marrow

Red bone marrow lies entirely within the Red bone marrow lies entirely within the spaces of bone, in the medullary cavity ospaces of bone, in the medullary cavity of young long bones and the spaces of spf young long bones and the spaces of spongy bone.ongy bone.

Bone marrow not active in blood cell forBone marrow not active in blood cell formation contains predominately adipose mation contains predominately adipose cells, giving it the appearance of adipose cells, giving it the appearance of adipose tissue.tissue.

Two types of bone marrowTwo types of bone marrow

a)a) Red bone marrowRed bone marrow due to the presence of due to the presence of

numerous erythrocyte numerous erythrocyte

b) Yellow bone marrowb) Yellow bone marrow rich in adipose cells, which rich in adipose cells, which

does not produce erythrocyte does not produce erythrocyte except under certain special except under certain special condition.condition.

Maturation of blood cellsMaturation of blood cells

Divided into three stageDivided into three stage Problasts stageProblasts stage Blasts stageBlasts stage Mature stageMature stage

Erythrocyte Erythrocyte

ProeythroblastProeythroblast Basophilic erythroblstBasophilic erythroblst Polychromatophilic erythroblastPolychromatophilic erythroblast NormoblastsNormoblasts ReticulocytesReticulocytes

Granulocytes Granulocytes

MyeloblastsMyeloblasts PromyelocytesPromyelocytes MyelocytesMyelocytes metamyelocytesmetamyelocytes

Lymphocytes and monocytesLymphocytes and monocytes

LymphoblastsLymphoblasts are the precursor cell are the precursor cell of lymphocytes, spherical, basophilic of lymphocytes, spherical, basophilic cytoplasm and no azurophilic cytoplasm and no azurophilic granules.granules.

Lymphoblast give rise to Lymphoblast give rise to prolymphocytesprolymphocytes, smaller, basophilic , smaller, basophilic may contain azurophilic granules.may contain azurophilic granules.

Prolymphocytes gives rise directly to Prolymphocytes gives rise directly to circulating lymphocytes.circulating lymphocytes.

Monocytes develop from stem cell, Monocytes develop from stem cell, monoblastmonoblast

Monoblasts give rise to Monoblasts give rise to promonocytes, basophilic, azurophilic promonocytes, basophilic, azurophilic granulesgranules

Promonocytes give rise to monocytesPromonocytes give rise to monocytes

Platelets Platelets

Platelets originate in red bone Platelets originate in red bone marrow from the fragmentation of marrow from the fragmentation of cytoplasm of mature granular cytoplasm of mature granular megakaryocytes which themselves megakaryocytes which themselves have arisen by differentiation of have arisen by differentiation of megakaryoblasts.megakaryoblasts.

Megakaryocytes extend cytoplasmic Megakaryocytes extend cytoplasmic processes which become pinched off processes which become pinched off as platelets.as platelets.

SummarySummary

What is plasma?What is plasma? What do blood cells include?What do blood cells include? What is the characteristics of each kind What is the characteristics of each kind

of blood cells?of blood cells? What is the hemopoiesis?What is the hemopoiesis? What is the structure of bone marrow?What is the structure of bone marrow?

HomeworkHomework

Review the characteristics of blood Review the characteristics of blood cells.cells.

Prepare for the next lesson-chapter Prepare for the next lesson-chapter 10 muscle tissue.10 muscle tissue.