Blood Flashcards
Functions of blood
Transport of gases, nutrient, wastes… Maintains homeostasis Maintains osmotic balance Regulates Body temperature Protection from pathogens
Composition of blood
55% Plasma
45% cells
Plasma
- mostly water, proteins, Ions, inorganic salts, gases
- Tissue fluid: Plasma which leaks from capilarries into tissues
- Lymph: tissue fluid which is collected through lymph capillaries
Blood cells
erythrocytes
Leukocytes
- -> Granulocytes (neutrophils, eosinophils, basophils)
- –> Agranulocytes (Lymphocytes, monocytes)
Erythrocytes
- biconcave and flexible
- life span: 120 days
- Anisocytosis –> RBCs are of unequal size:
>Normocytes: 6-9
>Microcytes: less than 6
> Macrocytes: more than 9
produced in red bone marrow and destroyed in Spleen, liver, red marrow or blood stream
erythrocytosis: abnormal increase in number
Anemia: abnormal decrease in number
RBC membrane-associated proteins
Antigens on Surface –> determine blood group
Inner structure of RBC
- no nucleus and organelles!!!
- 33% hemoglobin
Hb is Globin and heme
Functions of RBCs
Transport of O2 and CO2
pH homeostasis
blood coagulation
Determination of blood groups
Reticulocyte
- immature form of erythrocyte
- larger, contains some organelles
- amount can increase in anemia or hypoxia
Platelets (Thrombocytes)
- boconvex, small
- no nucleus
- have processes when activated
- derived from megakaryocyte in bone marrow
- life span: 10 days
Formation of platelets
- in cytoplasm of megakaryocytes: many invaginations –> PLATELET DEMARCATION CHANNELS
Inner structure of platelet
Hyalomere
(outer, structural Zone, with open tubular System, cytoskeleton of microtubules and microfilaments)
Granulomere
(inner, organelles Zone, dense tubular System with ribosomes and granules
Alpha granules: Fibrinogen, coagulation factors…
Delta granules: ADF, ATF
Lysosomes with Enzymes)
Function of platelets
- Formation of blood clots
- Prevention of blood loss
Coagulation –> degranulation of platelets
Leukocytes
–> perform their function in tissue!
granulocytes
- spherical
- Multi lobed nucleus –> POLYMORPHONUCLEUAR
- contain Primary and secondary granules
- phagocytose and degranulate
- do not recirculate!!
Primary granules
- characteristic for granulocytes and agranulocytes
- 20% of all granules
- are lysosomes with hydrolytic enzymes
Secondary granules
- characteristic just for granulocytes
- specifically stained: pink/lilac in neutrophils, red in in eosinophils, blue in basophils
Neutrophils
- 50-70%
- Cytoplasm has Primary, secondary, tertiary and secretory granules
- Multi-lobed nucleus
- life span: 8-12 h in blood, 2-3 days in CT
Pools of neutrophils
Reserve pool: mature neutrophils in red bone marrow
Circulating pool: neutrophils in bloodstream
Marginated pool: neutrophils which are adherent to endothelial cells in small vessels
Function of neutrophils
- phygocytosis of foreign agents
- -> neutrophils are attracted by chemotactic Signals from Inflammation –> adhere to Endothelium, extend pseudopodia and leave blood
- dead neutrophils are main component of pus
- secretion:
Interleukins –> Tumor necrosis factor Alpha
Antibacterial and tssue breakdown tissue
Neutrophili and Neutrophenia
Neutrophilia: increase in neutrophil Count, in bacterial infections
Neutrophenia: decrease in Count, in viral infections
Eosinophils
1-4%
- bilobed nucleus
- Primary and secondary granules
- life span: 8-18 h in blood, several days in CT
Functions of eosinophils
- anti-parasitic activity
- associated with allergic reactions and chronic Inflammation (inactivate histamine, phagocytose antigen-antibody complex)
Basophils
> 1%
- Bilobed nucleus
- Primary and secondary nucleus
- life span: 3 days in blood, several days in CT
- similar to mast cells (have a common precursor)
- secondary granules contain histamine and heparin
Functions of basophils
- in allergies and anaphylaxix
- ->activated they undergo degranulation and initiate inflammatory Response
- release of specific granules of basophils and mast cells on second exposure to certain Antigens leads to anaphylactic shock
Agranulocytes
- spherical
- unlobed nucleus –> MONONUCLEAR
(Gegenteil von polymorphonucleuar) - contain only Primary granules (lysosomes)
- do not phagocytose!
Lymphocytes and Monocytes
Lymphocytes
20-30%
- small, medium and large (about 90% are small)
- contains mainly mitochondria, free ribosomes, Primary granules
- life span. few to several years
- can proliferate and recirculate!!!!
Functional classification of lymphocytes
T lymphocytes: differentaite in Thymus, responsible for cellular immunity
B lymphocytes: for humoral immunity, may differentiate into Plasma cells
Natural Killers.: rapid cytotoxic Response to VIRALLY infected cells and Tumor cells
Monocytes
3-10%
Largest
- small Primary granules and mitochondria
- life span: 1-2 days in blood, as macrophages months to years in CT
- kindey shaped nucleus
Functions of monocytes
- in tissues differentiate into macrophages
- give rise to macrophage phagocytic system
Functions of macrophages
- phagocytosis as defense or cleaup
- Antigen presentation (present Antigen to helper T) –> are called Antigen presenting cells APCs
- secretion of cytokines
Leukogram
- Neutrophils (40-60%)
- Lymphocytes (20-40%)
- Monocytes (3-10%)
- Eosinophils (1-4%)
- Basophils (>1%)
“never let Monkeys eat bananas”
in Children: more leukocytes in General and more lymphocytes until year 4
Blood cell development
Hematopoiesis
- Erythropoiesis
- Trhombopoiesis
- Leukopoiesis
normally occurs in red bone marrow, but lmyphocytes are also formed in lmypahtic tissue
Embryonic and fetal heamopoiesis phases
Yolk sac Phase
hepatic Phase
Medullary phase
Yolk sac haemopoiesis
- blood Islands in Mesoderm of yolk sac
- during 3-5th weeks: extraembryonic and intravascular
Hepatic haemopoiesis
- haemopoietic stem cells migrate into fetal Organs
5th week: liver
8th week: Thymus
12th week: Spleen
intraembryonic and extravascular
Medullary haemopoiesis
- starts during 3rd month
- during 3rd Trimester
- in red bone marrow
Monophyletic theory
- all blood cells reive from common hemopoietic stem cell (HSC) or pluripotential stem cell (PPSC)
- from HSC: common myleoid progentiro (CMP) and common lymphoid progenitor (CLP)
- CMP and CLP from Colony forming Units (CFU)
- from CMP:
> CFU-E/M (erthrocyte and megakaryocyte progenitor)
> CFU-G/M (granulocyte and monocyte progenitor) - from CLP: CFU-Ly (lmyphocyte progenitor)
Maturation of blood cells
- decrease in size (exception is megakaryocytes)
- Chromatin condensation
- future erythrocytes fill with hemoglobin
- future granulocytes produce Primary and seconary granules
- future monocytes produce Primary granules
- future lymphocytes enter blood and undergo extensive maturation in immune organs
Erythropoiesis stages
- Proerythroblast
- Basophilic erythroblast
- Polychromatophilic eryhtroblast
- Orhtochromatophilic eryhtroblast
- Reticulocyte
- Erythrocyte
Proerythroblast (stage)
- large
- light nucleus
- basophilic cytoplasm
- divides
Basophilic erythroblast (stage)
- less in Diameter
- basophilic
Polychomatophilic erythroblast (stage)
- intesive Synthesis of Hb
- Basophilic ribosomes and acidophilic Hb
- last form that is able to divide
Orthochomatophilic erythroblast (stage)
- organelles disappear!!!
- Acidiphilic cytoplasm
- Extrusion of nucleus!
Reticulocyte (stage)
- few ribosomes which look like basophilic network
Eryhtrocyte (stage)
- rate of eryhtropoiesis is controlled by Erythropoietin secreted by kidney
Thrombopoiesis stages
- Megakaryoblast
- Promegakaryocyte
- Megakaryocyte
- Thrombocytes (platelets)
Megakaryoblast (stage)
- round, unsegmented nucleus
- divides
Promegakaryocyte (stage)
- larger in Diameter
- endomitosis (mitosis without cytoplasmic and nucleic division)
- rate of division controlled by thrombopoietin secreted by kidney and liver
Megakaryocyte
- large, dense and multilobed nucleus
- 3 zones of cytoplasm
>Perinuclear: organelles and nucleus
>Intermediate: demarcation canals
>Marginal Zone: platelets are shedding
Granulopoiesis stages
- Myeloblast
- Promylocyte
- Myelocyte
- metamyelocyte
- Stab or band form of neutrophil
- Neutrophil, eosinophil, basophil
Myeloblast (stage)
- round nucleus
- divides
Promyelocyte (stage)
- oval nucleus
- development of Primary granules
- divides
Myelocyte (stage)
- oval nucleus
- development of secondary granules
- last form that is able to divide
Metamyelocyte (stage)
- kindey-form nucleus
- number of secretory granules increases
Stab or band form of neutrophil (stage)
- horeshoe shaped nucleus
- tertiary and secretory granules
Mature form of granulocytes (stage)
- segmented nucleus (3-5 in neutrophil, 2 in eosinophil, 2 in basophil)
- rate is controlled by grwoth factorws and cytokines
mast cells / stages
1- Mastoblast
2- Promastocyte (into tissue)
3- Mast cell
Monopoiesis stages
- Monoblast
- Promonocyte
- Monocyte
Monoblast (stage)
- round nucleus
. divides
Promonocyte (stage)
- development of Primary granules
- divides
Monocyte (stage)
- circulate in blood
- migrate into tissues and differentiate into macrophage
Lymphopoiesis stages
1- Lmyphoblast
2-Prolymphocyte
3- Lympocyte
Lymphoblast (stage)
- round nucleus
- divides
Prolmyphocyte (stage)
- development of Primary granules
- divides
Lymphocyte (stage)
- recirculates in blood and lmyph
- undergoes divisions and final maturation in immune Organs
