10.2 Lab + Lecture Notes Flashcards
Megakaryocyte
= large, appearing multinucleate cell
- always found basal to blood sinus (which might not always be apparent in plane of section)
- undergo endomitosis
Endomitosis
= chromosome duplication without division
- seen in megakaryocytes
What are the advantages of real world microscope over virtual slides
1) Helpful to focus though cell - aiding in identification of nucleoli, primary and secondary granules
2) Helpful to adjust light source
- narrow aperture = benefits resolving power as expense of color
- wide aperture = better color contrast
Which hemoatopoietic lineage is more dependent on color contrast and which is more dependent on resolution of the slides for identification
- Resolution = important for granulocyte precursors
- Color = important for erythrocyte precursors
Describe the key morphologic features of proerythroblast cells
- large cell nucleoli and cytoplasm
- ranges from neutral to basophilic
- in common preparations is not distinguishable from myeloblast
Describe the key morphologic features of basophilic erythroblast cells
- large (usually slightly smaller than proerythroblast cells)
- basophilic cytoplasm
- lack nucleoli
Describe the key morphologic features of polychromatic erythroblast cells
- average-sized cell
- cytoplasm intermediate in color between basophilic and eosinophilic extremes
Describe the key morphologic features of othrochromatic erythroblast cells
- average-size cells
- cytoplasm equivalent in color to that of reticulocytes
Describe the key morphologic features of reticulocytes
- small, spherical eosinophilic cells
- lacks nucleus
- remnants of intracellular organelles can be visualized with special stains
- stage where cell leaves the marrow (erythrocytes are not present within the marrow - developed from reticulocytes within the blood)
Describe the key morphologic features of myeloblast cells
- large cell
- nucleoli
- not distinguishable from proerythroblast
Describe the key morphologic features of promyelocyte cells
- smaller cell
- nucleoli
- azurophilic granules appearing –> often near golgi
Describe the key morphologic features of early myelocyte cells
- need to indicate neutrophilic, basophilic, eosinophilic from this stage on in naming
- few specific granules being to accumulate intracellular
- round nucleus
Describe the key morphologic features of late lyelocyte cells
- many specific granules
- bean shaped nucleus
Describe the key morphologic features of metamyelocyte cells
- V-shaped nucleus (has an acute angle of indentation
- No basophilic metamyelocytes in LM because basophilic granules obscure the outline of nucleus
Describe the key morphologic features of band cells
= also called stab cells
- neutrophilic by definition
- C-shaped nucleus (usually no acute indents - but consider the orientation of the cell)
- 2% normally in peripheral blood
Describe the overall key morphologic features of mature granulocyte cells
- Segment nucleus
- granulocytes normally leave the bone marrow in the mature form
- if there is a large demand or a pathology may leave as late precursors as well
Nucleoli
- in common stains for blood and marrow (Wright’s, Romanovsky, Giemsa) they appear as light circular regions inside nucleus
- need to distinguish them from euchromatin/heterochromatin
- largest cells in marrow will contain nucleoli
Azurophilic granules
= extremely small granules (primary) just at the limit of LM
- blue granules in precursor cells of granulocyte lineages (promyelocyte and then in decreasing number in each of the subsequent precursors as the specific granules are increasingly produced)
Describe the general strategy for identifying marrow cells
1) Do not identify cells that are broken/damaged or not round, and regions where cells are too close or too far apart
2) Triage into 1 of 3 categories
2A) Large nucleated cells –> erythroblast, myeloblast (both will just be called blast cells) or promyelocyte
2B) Smaller cells with round nuclei and no granules = erythrocytic lineage
2C) Smaller cells with indented (bean, V, C, lobed) nuclei = granulocytic lineage = most will be neutraphils
3) Evaluate overall slide for: color, azurophilic granules, neutrophilic/eosinophilic granules
4) ID using the 3 observations - weighing key features the highest
Red Marrow
= hematopoietically active
- predominant until age 4
- in adult red marrow is confined to ends of long bones + middle of some flat bones
- ilium crest = area where we prefer to take marrow biopsies from
Yellow Marrow
= formed when hematopoietic activity declines
- adipocytes replace hematopoietic island
- balance between red and yellow marrow is dynamic - depends on demand for hematopoiesis
Stroma
= supporting tissue
ex. adipose tissue; reticular cells; CT (fibroblasts/CT and the cells that make it); blood supply
Parenchyma
=”functional tissue”
- developing blood cells (hematopoietic islands)
What is bone Marrow stroma
= cells that collaborate to control development and release of the hematopoietic cells
- contains mesenchymal derived cells and hematopoietic derived cells
- all marrow stromal cells are active in regulating + supporting hematopoiesis –> secreting cytokines fro growth, division, apoptosis as necessary
Describe the Hematopoietic derived Bone marrow stromal cells
- osteoclasts
- macrophages (monocytes) –> where born in the marrow –> entered the blood –> and then returned to the CT of marrow
Describe the mesenchymal derived Bone marrow stromal cells
- osteoblasts
- adipocytes
- fibroblasts
- endothelial cells
Stem cells
- renew themselves
- totipotent
- don’t exists in adult
- these are embryonic stem cells
Pluripotent Hematopoietic Stem Cell (PHSC)
= stem cell for blood - all cells come from it <0.015 of nucleated cells in marrow - give rise to 2 progenitor cells 1) CMP - myeloid = everything else in blood except lymphocytes 2) CLP - lymphoid - T and B lymphocytes
Progenitors
= renew themselves
- give rise to restricted cell lines
- hematopoietically derived cells not listed in our drawings include mast cells, plasma cells, dendritic cells, NK-cells
What does CMP give rise to
- CFU-Eos (eosinophils)
- CFU-B (basophils)
- CFU-GM –> CFU-G (neutrophils) + CFU-M (monocytes)
- CFU-megakarocyte (platelets)
- ## BFU-E –> CFU-E (erythrocyte)Used to be known as CFU-S (spleen)
What does CLP give rise to
- CFU-LyT (T-lymphocyte)
- ## CFU-LyB (B-lymphocyte)Used to be known as CFU-Ly (lymphocyte)
Precursors
- generate daughter cells that are more differentiated than the parent cell
- progenitors (CFUs) - can make more of them selves while precursors cannot
- 1st precursor cell in each lineage = blast
ex. - proerythroblasts –> form erythocytes
myeloblasts –> from granulocytes
CD Markers
- see in all except RBC
-are not just for blood - presence or absence can be useful in ID of a cell
- CD expression can be dependent on stage of differentiation (i.e. 45+ = all except RBC lineage from CMP –> mature; 33+ = same as 45+ except it excludes the progenitors)
- CD molecules are FXNlly significant to cell
(ex.
CD34= cell adhesion molecule;
CD14= receptor for molecules found on bacteria;
CD3= part of T-cell receptor complex;
CD4= helper T-cell;
CD8= cytotoxic T-cell)
Describe the erythrocyte Precursor lineage
1) Proerythroblast
2) basophilic erythroblast
3) Polychromatic erythroblast
4) Orthochromatic erythroblast
5) Reticulocyte
Describe the Granulocyte Precursor Lineage
1) Myeloblast
2) Promyelocyte
3) Early (E/N/B) Myelocyte
4) late (E/N/B) Myelocyte
5) Metamyelocyte (E/N)
6) Band Cell (N), Mature E or B
7) Mature N
Describe Regulation of Erythropoiesis
- EPO rescues BFU-E and CFU-E from apoptosis - preventing a few erythrocyte progenitor cells from dying allow for more RBC production
- is regulated by substances normally present in marrow stroma
1) G-CSF (granulocyte colony stimulating factor)
2) SCF ( stem cell factor)
3) IL3
4) Cytokine = Erythropoietin (EPO)
Describe the regulation of EPO
- [Oxygen]
- renin-angiotensin system (sensing BP)
- other hormones –> i.e. insulin
Describe Erythropoiesis of progenitors
CMP - generates all lymphoid lineages
- BFU-E
- CFU- E
Describe BFU-E
= progenitor Cell
- motile - can present in peripheral blood
- requires several cytokines for survival
- high proliferative potential
- 14 days to RBCs in culture
Describe CFU-E
= progenitor cell
- highly dependent on EPO
- 7 days to RBC in culture
- non-motile
- found in marrow only
Describe proerythroblast
- nucleoli present in nucleus
- no granules in cytoplasm
describe basophilic erythroblast
= fine chromatin clumps in nucleus
- basophilic cytoplasm
Describe polychromatophilic erythroblast
- coarse chromatin clumps in nucleus
- grey-blue cytoplasm
- last stage for mitosis
describe orthochromatophilic erythroblast
- chromatin very condensed
- cytoplasm like RBC’s in color
Describe reticulocyte
- no nucleus
- fine strands in cytoplasm
- frequency in peripheral blood depends on activity
Compare granulocyte and RBCs in reference to their exit from bone marrow
- Granulocytes –> leave marrow as band cells or mature forms - are present at 3% in peripheral blood
- RBCs –> leave marrow as reticulocytes (immature forms) - are still finishing Hb production at this time - are present at <1.5% in peripheral blood
Reticulocyte ultrastructure
- leave marrow by piercing through endothelial cells
- mitochondria and polysomes are still finishing the Hb production
- Biconcave RBC shape is formed in circulation so they are still in spherical shape
Describe neurtrophilic granules
- secrete IL-1 = pyrogen
- Tertiary granules = facilitate migration to target - followed by neutraphil phagocytosis - engulfing bacteria - internalizing it in phagosome (has decreased pH)
- specific (secondary) granules - kill bacteria with enzymes and ROS (by binding with phagosome)
- azurophilic (primary) granules - lysosomal enzymes digest bacteria
Describe eosinophilic granules
- specific granules have a very distinctive EM appearance
- Internum = electron-dense crystalloid body containing major basic protein (causes line across granule), eos cationic protein, parasitic neurotoxins)
- Externum = aryl sulfatase, histaminase, acid phosphatase
Describe basophilic granules
- have distinct granules in EM
- contain inflammatory substances –> histamine (vasodilator) + heparin (anti-coagulant)
Describe Monocyte Developmental lineage
1) CFU-GM (progenitor)
2) CFU-M (progenitor)
3) Monoblast (precursor)
4) Promonocyte (precursor)
5) Monocyte (blood)
6) Macrophage, dendritic cells, osteoclasts (in tissue)
Describe Lymphocyte Developmental Lineage
1) CFU-Ly (progenitor) 2A) CFU-LyB (progenitor) 2B) CFU-LyT (progenitor) 3) Lymphoblast (precursor) 4) Proplymphocyte (precursor) 5) Lymphocyte (blood) 6) Ly-B, Ly-T, NK-Cells, Interstitial plasma cells (tissue)
Megakaryocyte
- reside exclusively in bone marrow
- huge cells
- release pre platelets into sinusoid –> mature into platelets in circulation
- polyploid cells (1 nucleus but many copies of DNA) - as a result of endomitotic division
- promegakaryocytes = have their adult chromosome content - the amount is related to number of platelets produced
Developmental Lineage:
CMP –> CFU-Meg–> (Pro-)Megakaryoblast –> (Pro-)Megakaryocyte
Megakaryocyte ultrastructure
- platelet demarcation channels form in cytoplasm
- 8000 platelets per megakaryocyte
- can see endomitosis in EM
- processess extend through sinus capillaries into sinus lumen –> pre-platelets are pinched off in lumen
Diseases of Bone Marrow
- bone marrow and thymus = primary lymphoid organs
- disorders of marrow function can cause anemias or leukemias (= disorders of WBC proaction - might see circulating precursors)
- hematopoiesis can be controlled pharmacologically
Diseases of Bone Marrow
- bone marrow and thymus = primary lymphoid organs
- disorders of marrow function can cause anemias or leukemias (= disorders of WBC proaction - might see circulating precursors)
- hematopoiesis can be controlled pharmacologically
What are the 4 cytokines often used as drugs and what cells do they com from
1) G-CSF (neutrophils)
2) GM-CSF ( leukocytes)
3) EPO (erythrocytes)
4) IL-2 (T-cells)
What are the 4 cytokines often used as drugs and what cells do they com from
1) G-CSF (neutrophils)
2) GM-CSF ( leukocytes)
3) EPO (erythrocytes)
4) IL-2 (T-cells)
Describe Anemia
- reduction in O2 carrying capacity of blood
- ## causes include: blood loss via trauma/genetic defect; kidney disease (kidney and liver make EPO); bone marrow cancertaxonomy of anemias
a) too few RBCs - too few produced or to many lost/destroyed
b) too many RBCs - polycythemia
C) right # but - too small or too large or wrong shape
Describe Anemia
- reduction in O2 carrying capacity of blood
- ## causes include: blood loss via trauma/genetic defect; kidney disease (kidney and liver make EPO); bone marrow cancertaxonomy of anemias
a) too few RBCs - too few produced or to many lost/destroyed
b) too many RBCs - polycythemia
C) right # but - too small or too large or wrong shape
What are the 4 leukemias described in class and Describe the basic classification system
- ALL, AML, CLL, CML
First Letter
= A = acute = few matter circulating cells
= C = chronic = abnormal FXN in circulating cells
Second Letter
= M = myelongenous = affecting myeloid cells
= L = lymphatic = affecting lymphatic cells
Third Letter
= L = Leukemia = adbnormal proliferation of leukocytes (why it is sometimes called “cancer of blood”)
What are the 4 leukemias described in class and Describe the basic classification system
- ALL, AML, CLL, CML
First Letter
= A = acute = few matter circulating cells
= C = chronic = abnormal FXN in circulating cells
Second Letter
= M = myelongenous = affecting myeloid cells
= L = lymphatic = affecting lymphatic cells
Third Letter
= L = Leukemia = abnormal proliferation of leukocytes (why it is sometimes called “cancer of blood”)
Describe AML
- peripheral blood –> most cells are myeloblasts (nucleoli), contains many cells normally found in marrow
- very few mature leukocytes in blood
- Marrow: is full of rapidly dividing immature cells - that do not differentiate
- normal cell in marrow are affected by crowding (anemia and bleeding are common)
- treatment includes drugs, radiation, bone marrow transplant, autologous stem cell transplants
Describe AML
- peripheral blood –> most cells are myeloblasts (nucleoli), contains many cells normally found in marrow
- very few mature leukocytes in blood
- Marrow: is full of rapidly dividing immature cells - that do not differentiate
- normal cell in marrow are affected by crowding (anemia and bleeding are common)
- treatment includes drugs, radiation, bone marrow transplant, autologous stem cell transplants
