Blood and Haemopoiesis

Overview of Blood Blood is a fluid connective tissue. Blood is a fluid connective tissue. Its total volume is about 6 liters. Its total volume is about 6 liters. It has many functions. It has many functions. Blood is made of two parts: blood cells and plasma. Blood is made of two parts: blood cells and plasma.

Main Functions Transport of nutrients and oxygen to cells. Transport of nutrients and oxygen to cells. Transport of wastes and carbon dioxide away from cells. Transport of wastes and carbon dioxide away from cells. Delivery of hormones and other regulatory substances to and from cells and tissues. Delivery of hormones and other regulatory substances to and from cells and tissues. Maintenance of homeostasis. Maintenance of homeostasis. Transport of humoral agent and cells of the immune system. Transport of humoral agent and cells of the immune system.

Plasma Acellular fluid in which blood cells are suspended Acellular fluid in which blood cells are suspended Its main component is water. Its main component is water. A variety of solutes,including proteins (albumin, fibrinogen), dissolved gases (oxygen, carbon dioxide), electrolytes (Na, Mg,Ca), nutrients (glucose, lipids), regulatory substances (hormones, enzymes) and waste materials (drugs urea). A variety of solutes,including proteins (albumin, fibrinogen), dissolved gases (oxygen, carbon dioxide), electrolytes (Na, Mg,Ca), nutrients (glucose, lipids), regulatory substances (hormones, enzymes) and waste materials (drugs urea).

What do blood cells include?  Platelets  Erythrocytes  Leukocytes neutrophils granulocytes eosinophils lymphocytes agranulocytes basophils monocytes

Erythrocytes 4.4-5×10 12 / L (F) 5×10 12 / L (M) Anucleate, biconcave disks. Anucleate, biconcave disks. Quite flexible. Quite flexible. Packed with protein hemoglobin ( g/L). Packed with protein hemoglobin ( g/L). Few reticulocytes. Few reticulocytes.

Membrane proteins Integral membrane proteins: express blood group antigens, attach cytoskeletal protein network to the cell membrane. Integral membrane proteins: express blood group antigens, attach cytoskeletal protein network to the cell membrane. Peripheral membrane proteins: organized into cytoskeletal protein network. Peripheral membrane proteins: organized into cytoskeletal protein network.

Leukocytes 4~10×10 9 / L Possess two types of granules: specific granules and azurophilic granules. Possess two types of granules: specific granules and azurophilic granules. Granulocytes have nuclei with two or more lobes. Granulocytes have nuclei with two or more lobes. Include the neutrophils, eosinophils, and basophils. Include the neutrophils, eosinophils, and basophils. Involved in body’s cellular and humoral defense against foreign material. Involved in body’s cellular and humoral defense against foreign material. Granulocytes

Neutrophils 50~70% Spherical, with a nucleus consisting of two to five lobes. Spherical, with a nucleus consisting of two to five lobes. The active phagocytes of bacteria and other foreign agents. The active phagocytes of bacteria and other foreign agents. Specific granules: collagenase, phospholipase Specific granules: collagenase, phospholipase Azurophilic granules: myeloperoxidase (kill bacteria), acid hydrolases and defensin (digest foreign agents) Azurophilic granules: myeloperoxidase (kill bacteria), acid hydrolases and defensin (digest foreign agents) Tertiary granules: phosphatases, gelatinases and collagenases. Tertiary granules: phosphatases, gelatinases and collagenases.

Eosinophils 0.5~3% Nuclei are bilobed. Nuclei are bilobed. Large and elongated refractile specific granules. Large and elongated refractile specific granules. Associated with allergic reactions, parasitic infections. Associated with allergic reactions, parasitic infections.

Eosinophils Specific granules: major basic protein (MBP), eosinophil cationic protein(ECP), eosinophil peroxidase(EPO) and eosinophil-derived neurotoxin (EDN); Specific granules: major basic protein (MBP), eosinophil cationic protein(ECP), eosinophil peroxidase(EPO) and eosinophil-derived neurotoxin (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.

Basophils 0~1% Nucleus is divided into irregular lobes. Nucleus is divided into irregular lobes. Specific granules are few and irregular in size and shape. Contain heparan sulfate, histamine, and slow-reacting substance of anaphylaxis (SAS-A). Specific granules are few and irregular in size and shape. Contain heparan sulfate, histamine, and slow-reacting substance of anaphylaxis (SAS-A). Participate in anaphylaxis, anticoagulation. Participate in anaphylaxis, anticoagulation.

Leukocytes-agranulocytes Do not have specific granules, but contain azurophilic granules. Do not have specific granules, but contain azurophilic granules. The nucleus is round or indented. The nucleus is round or indented. Includes lymphocytes and monocytes. Includes lymphocytes and monocytes.

Lymphocytes 20~30% The spherical cell has a spherical nucleus with an indentation. The spherical cell has a spherical nucleus with an indentation. The cytoplasm is scanty. The cytoplasm is scanty. All related to immune reactions. All related to immune reactions.

Monocytes 3~8% The largest cells of the leukocytes. The largest cells of the leukocytes. The nucleus is oval, eccentrically placed. The nucleus is oval, eccentrically placed. Precursors of the cells of the mononuclear phagocytotic system. Precursors of the cells of the mononuclear phagocytotic system.

Platelets 100~400×10 9 / L Nonnucleated 2-4 um, cytoplasmic fragments derived from megakaryocytes. Nonnucleated 2-4 um, cytoplasmic fragments derived from megakaryocytes. Promote blood clotting and help repair gaps in the walls of blood vessels. Promote blood clotting and help repair gaps in the walls of blood vessels.

Each platelet has a peripheral light blue-stained transparent zone, the hyalomere and a central zone containing purple granules, called the granulomere. Each platelet has a peripheral light blue-stained transparent zone, the hyalomere and a central zone containing purple granules, called the granulomere. cell coat rich in glycosaminoglycans and glycoproteins involved in platelets adhesion. cell coat rich in glycosaminoglycans and glycoproteins involved in platelets adhesion.

Haemopoiesis Hemopoiesis includes both erythropoiesis and leukopoiesis, as well as thrombopoiesis. Hemopoiesis includes both erythropoiesis and leukopoiesis, as well as thrombopoiesis. In the adult, erythrocytes,granulocytes, monocytes, and platelets are formed in the red bone marrow; lymphocytes are also formed in the red bone marrow and in the lymphatic tissues. In the adult, erythrocytes,granulocytes, monocytes, and platelets are formed in the red bone marrow; lymphocytes are also formed in the red bone marrow and in the lymphatic tissues.

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

Monophyletic theory Pluripotential stem cell (PPSC) differentiate into multipotential myeloid stem cell and multipotential lymphoid stem cell. Pluripotential stem cell (PPSC) differentiate into multipotential myeloid stem cell and multipotential lymphoid stem cell. Multipotential myeloid stem cell only in bone marrow and give rise to all blood cells other than lymphocytes. Multipotential myeloid stem cell only in bone marrow and give rise to all blood cells other than lymphocytes. Multipotential lymphoid stem cell in bone marrow and in lymphoid tissues,give rise to lymphocytes. Multipotential lymphoid stem cell in bone marrow and in lymphoid tissues,give rise to lymphocytes.

Bone Marrow Red bone marrow lies entirely within the spaces of bone, in the medullary cavity of young long bones and the spaces of spongy bone. Red bone marrow lies entirely within the spaces of bone, in the medullary cavity of young long bones and the spaces of spongy bone. Bone marrow not active in blood cell formation contains predominately adipose cells, giving it the appearance of adipose tissue. Bone marrow not active in blood cell formation contains predominately adipose cells, giving it the appearance of adipose tissue.

Two types of bone marrow a) Red bone marrow due to the presence of numerous erythrocyte due to the presence of numerous erythrocyte b) Yellow bone marrow rich in adipose cells, which does not produce erythrocyte except under certain special condition. rich in adipose cells, which does not produce erythrocyte except under certain special condition.

Maturation of blood cells Divided into three stage Divided into three stage Problasts stage Problasts stage Blasts stage Blasts stage Mature stage Mature stage

Erythrocyte Proeythroblast Proeythroblast Basophilic erythroblst Basophilic erythroblst Polychromatophilic erythroblast Polychromatophilic erythroblast Normoblasts Normoblasts Reticulocytes Reticulocytes

Granulocytes Myeloblasts Myeloblasts Promyelocytes Promyelocytes Myelocytes Myelocytes metamyelocytes metamyelocytes

Lymphocytes and monocytes Lymphoblasts are the precursor cell of lymphocytes, spherical, basophilic cytoplasm and no azurophilic granules. Lymphoblasts are the precursor cell of lymphocytes, spherical, basophilic cytoplasm and no azurophilic granules. Lymphoblast give rise to prolymphocytes, smaller, basophilic may contain azurophilic granules. Lymphoblast give rise to prolymphocytes, smaller, basophilic may contain azurophilic granules. Prolymphocytes gives rise directly to circulating lymphocytes. Prolymphocytes gives rise directly to circulating lymphocytes.

Monocytes develop from stem cell, monoblast Monocytes develop from stem cell, monoblast Monoblasts give rise to promonocytes, basophilic, azurophilic granules Monoblasts give rise to promonocytes, basophilic, azurophilic granules Promonocytes give rise to monocytes Promonocytes give rise to monocytes

Platelets Platelets originate in red bone marrow from the fragmentation of cytoplasm of mature granular megakaryocytes which themselves have arisen by differentiation of megakaryoblasts. Platelets originate in red bone marrow from the fragmentation of cytoplasm of mature granular megakaryocytes which themselves have arisen by differentiation of megakaryoblasts. Megakaryocytes extend cytoplasmic processes which become pinched off as platelets. Megakaryocytes extend cytoplasmic processes which become pinched off as platelets.

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

Homework Review the characteristics of blood cells. Review the characteristics of blood cells. Prepare for the next lesson-chapter 10 muscle tissue. Prepare for the next lesson-chapter 10 muscle tissue.