Haematopoeisis Flashcards
Haematology is the study of
Blood, organs that make blood and diseases that affect blood
Blood forming organs include
Liver,thymus,spleen,yolk sac,bone marrow
What is blood
Blood is a group of cells that float in a liquid called PLASMA
The liquid that Carries blood cells is made up of what
Lipid,carbs,protein,blood cells,salt etc but majorly water
What are the blood cells
Erythrocytes
Leukocytes
Thrombocytes
What is heamtopoesis
Heamtopoesis is the formation of blood cells
Formation of leukocytes is called
Leukopoeisis
Leukopoiesis is the formation of
Granulocytes, monocytes
Magakaryopeisis is the formation of
And it is also called
Platelets
Also called thrombopoeisis
Haematopoeisis is regulated by
Glycoproteins hormones
Glycoproteins hormones known as
Growth factor
The compartments or stages to the formation of blood cells are
Stem cells compartment
Progenitor compartment
Precursor compartment
Stem cells are defined as
Undifferentiated cells that can divide for indefinite periods of time and be able to provide offsprings cells that are specialized
Multi potential cells are
Stem cells
What are multi potential cells
Cells capable of giving rise to family of blood cells
Stem cells have self renewal potential
TRUE/FALSE
TRUE
A pluripotent cells
Is a cells that can differentiate to all types of blood cells
A progenitor cells
Is a cells that can only produce one lineage of blood cells
Progenitor cells produce little self renewal
TRUE/FALSE
True
Macromolecules in a haematopoetic environment includes
Collagen
Fibronectin
Thrombospondin
Tenascin
Ontogeny is the
Origination and Development of an organism (both physical and psychological)
Ontogeny of heamtopoesis
Fetus-
3-6 weeks of gestation
Yolk sac
Blood is produced where during the 6-22 week of gestation
Liver,spleen
Blood is produed where at 5-9 months of intra-uterine life
Bone marrow
Infants undergoes haematopoeisis at
Bone marrow ( all bones)
Adults produces blood cells at there
Bones which are
STERNUM,ribs, vertebrae, sacrum,pelvis, proximal end of femur
Extra medullary haematopoeisis is taken up by which organ in adult hood
Liver and spleen
Surrogate markers of HSC are
CD34
What regulates haematopoeisis
Growth factors
Growth factor and target cells
1)Stem cell factor
2)Flt ligand
3)Interleukin 3
4)Interleukin 6
5)Thrombopoetin
1)Pluripotent haematopoetic stem cell
2)PHSC
3)multipotent progenitors
4)multipotent progenitors,B-lmyphocyte, megakaryocytes
5)multipotent progenitors
A single proerythroblast give rise to
16 matured red blood cell
Reticulocyte can be identified by
Staining with methylene blue
Regulators of erythropoiesis
Erythropoietin
Vitamin b12
Iron
Folic acid
Vitamin B6 (pyridoxine or pyridoxial phosphate PLP)
Regulators of red blood cells include
Vitamin E
Protein
Carbs
Hormones- thyroxin and androgens
Megakarypoesis is the formation of
Platelets
Megakaryocytes differentiate by
Endo mitosis
Regulators of megakaryocytes are
Thrombopoetin and cytokines
Life span of leucopoeisis
6-10 days
Neutrophils life span
6hrs in blood
2-4 days in tissues
Life span of eythropoeisis
6-7 days from pro erythroblast to reticulocyte
Reticulocyte to fully matured red blood cells takes
2-3days
Life span of red blood cells
100-120days
Life span of platelets
7-10days
What are the two types of stem cells that comes from pluripotent stem cells
Long term stem cells
Short term stem cells
Myeloid stem cells give rise to
RBC
WBC
PLATELETS
Eosinophils
Basophils
Neutrophils
Lymphoid stem cells give rise to
Lymphocytes ( T AND B Lymphocytes )and natural killers
Self renewal characteristics and of stem cells means
One cell will replace the differentiating stem cells while the stem cell will continue to the progenitor phase
What is a stem cell
An unspecialized cell that can differentiate into any specialized cell and another stem cell
Stem cell niches are found
Spongy bone( cancellous bones)
What happens in red bone marrow
Active heamtopoesis
What happens in yellow bone marrow
Fat,capillaries, reticular cell, inactive haematopoeisis
What are the stem cell niches
Endostealum niche
Vascular niche
What is a niche
A niche is a site where something is located at signals can be sent there
Characteristics of endostealum niche
Inhibition of differentiation
Self renewal
Stem cells migrate from the surface of the endostealum to the blood vessels to
Differentiate ( vascular niche)
What does growth factor do
Regulate proliferation and maturation( without growth factor, cells will not grow)
Where is erythropoietin produced and what does it do
Kidney
Increases erythrocytes precursor
Where is thrombopoetin produed and function
Liver
Stimulate platelet formation
Main stimuli of erythropoesis
Hypoxia
Extra medullary haematopoeisis is a condition where
The liver and the spleen helps in the production of blood cells when the long bones are not efficient in a disease
Stem cells repopulate a bone marrow by process of
Chemotherapy or lethal irridation
CD34+ and CD38- is a marker that indicated that
Long term haematopoetic stem cells are present in bone marrow and absent in bone marrow respectively
Secondary organs for producing lymphocytes (B and T)
Spleen thymus and lymph nodes
Stromal cells that maintain the survival and function of a stem cell include
Micro environment niche for stem cell
Fibroblast, endothelial cells, mesenchymal stem cell, adipocytes, plasma cells, lymphocytes, macrophages
These stomal cells major job is to
Secrete glycoproteins
Glycoproteins act as a hormone to haematopoetic stem cells
True
Properties of growth factor
1) they may act where they are produced(BM) or act in plasma( erythropoietin)
2) they act on low concentration
3)produced by many cell types
4) may act on more than one lineage
5) have multiple actions
6) two or more growth factor can work together ( synergise) to produce one cell lineage
Major source of growth factor
Stromal cells
Thrombopoetin growth factor is 90% secreted by
Liver
Apoptosis is
Programmed cell death
Haematopoeisis takes place in a conducive
Microenvironment
What growth factor stimulates multipotent progenitors
Interleukin 3
interleukin 6
Interleukin 5 is a growth factor to
Colony stimulating factor for eosinophils
Megakaryocytes growth factor stimulant is
Interleukin 6
thrombopoetin( majorly)
Erythopoeitin target cell is
Erythroid progenitor cell
Two types of stem cells
Self renewal stem cell
Stem differentiating stem cells
Asymmetric population of stem cells implies that
Not all stem cells in a population performs the same job
Stem cell plasticity
Stem cells have the capabilities of becoming another type of cell other than blood cell
Uncommitted stem cells are called
Pluripotent stem cells
Committed stem cells are called
Progenitor stem cell
At what compartment are we able to identify the nature of the cell under the microscope
Precursor compartment
The major part that we find stem cell in bone marrow is
Perivascular space