Hematopoiesis

what is blood composed of

plasma and formed elements (RBC, WBC, platelets)

white cells include

granulocytes and lymphocytes

what is blood composed of

plasma and formed elements (RBC, WBC, platelets)

white cells include

granulocytes and lymphocytes

what cells are granulocytes and what are they important in

neutrophils, eosinophils, basophils; important in innate immune system

what cells are lymphocytes and what are they important in

B cells and T cells; important in adaptive immune system

what are platelets

pieces of megakaryocytes

what do platelets contribute to

work with circulating coagulation factors to effect hemostasis

what is hemostasis

the normal clotting of blood in response to injury

what is another word for platelets

thrombocytes

what is the exact definition of anemia

decreased oxygen carrying capacity due to deficiency of erythrocytes; decreased hemoglobin

what does -penia mean

too few

what does -cytosis mean

too many

stem cells in embryos are

pluripotent

hematopoietic stem cells are

multipotent

what is the difference between pluripotent and multipotent

pluripotent means it can develop into many different tissues while multipotent means it is limited to one type of tissue but can develop into various cells within the tissue

what are the 2 ways stem cells replicate or differentiate

1) asymmetric replication

2) stochastic differentiation

what is asymmetric replication of stem cells

one daughter cell retains its self renewing capacity while second daughter enters a differentiation pathway

what is stochastic differentiation of stem cells

balance between stem cell divisions that generate either 2 self-renewing stem cells or 2 daughter cells that differentiate

what are the requirements for a stem cell to be a stem cell

they must have the capacity for proliferation, differentiation, and self-renewal

what is a CBC

complete blood count

what things might you see in a CBC

hematocrit, hemoglobin, WBC count, RBC count, platelet count, reticulocytes, MCV, etc

what is the lifespan of RBCs in the blood

120 days

what is the lifespan of granulocytes in the blood

several days

what is the lifespan of platelets in the blood

~10 days

what is hematopoiesis

the process of blood cell production

where does hematopoiesis occur

bone marrow

what 4 things does hematopoiesis involve

cell renewal, proliferation, differentiation, maturation

what does hematopoiesis respond to

increased demand such as blood loss, infection, or increased cellular turnover

all hematopoietic lineages are derived from what common progenitor

the hematopoietic stem cell (HSC)

HSCs develop into which 2 common progenitors

common myeloid progenitor and common lymphoid progenitor

what do the common myeloid progenitor develop into

1) megakaryocyte

2) erythrocyte

3) mast cell

4) myeloblast

what do myeloblasts differentiate into

basophils, neutrophils, eosinophils, monocytes

what do the common lymphoid progenitor develop into

natural killer cell and small lymphocytes (which differentiate into T and B lymphocytes)

what are the 6 stages of myeloid maturation

myeloblast —> promyelocyte —> myelocyte —> metamyelocyte —> band —> neutrophil

what is the left shift

presence of immature myeloid cells in peripheral blood

what are 3 relevant growth factors to recognize

TPO (thrombopoietin)

EPO (erythropoietin)

G-CSF (granulocyte colony-stimulating factor)

where does EPO come from

kidney

where does G-CSF come from

macrophages and fibroblasts (other white cells)

where does TPO come from

liver

why do we care about hematopoiesis as health care providers

if a pt has too many or too few blood cells or platelets, we need to figure out why; it could be from blood loss, infections, diseases, etc

what disease does bone marrow failure account for

pancytopenia AKA universal low blood cell counts

what are 5 causes for pancytopenia

1) autoimmune disease

2) inherited genetic disorders

3) extrinsic insults

4) clonal diseases such as blood cancers

5) nutritional deficits (severe) such as B12 or folate

what if only one cell line is too low?

most likely not a problem of the bone marrow

what are 4 clinical features associated with anemia

1) severe fatigue

2) dyspnea

3) need transfusions

4) headaches and dizziness

what are 2 clinical features associated with thrombocytopenia

1) petechiae, bruises, mucosal bleeding

2) need transfusions

what are 4 clinical features associated with neutropenia

1) severe fatigue

2) oral ulcers, HSV, thrush

3) soft tissue infections

4) risk for sepsis

the treatment depends on the

diagnosis or cause

besides transfusions, what other treatments can be used for cytopenia(s)

1) nutrients important for hematopoiesis

2) antibiotics

3) hematopoietic growth factors

EPO is used for anemia to combat what 2 things

1) chronic kidney disease

2) other causes of halted RBC production

G-CSF is used for neutropenia to combat what

mostly chemotherapy-induced neutropenia

TPO is used for thrombocytopenia to combat what 3 things

1) immune mediated thrombocytopenia

2) aplastic anemia

3) chemotherapy-associated thrombocytopenia

when HSCs are used to treat disease, what is this known as

bone marrow transplant

what is autologous bone marrow transplant

uses patients own stem cells

what is allogeneic bone marrow transplant

uses donors stem cells

where are 3 places we can get HSCs from to use in bone marrow transplants

1) bone marrow

2) peripheral blood stem cells

3) placenta cord blood