Blood (5) Flashcards
Constitutive Hematopoiesis
Constant formation of cells to maintain the appropriate number
Stress Hematopoiesis
Induced form when need for new blood and immune cells exceeds their steady state (constitutive) production
e.g. hypoxia
Hematopoiesis location Fetus vs Adult
- Fetus: Yolk sac - Liver - Bone marrow (red)
- Adult: Axial skeleton (pelvis, sternum, vertebrae, long bones)
Types of Bone marrow
- Yellow BM: Inactive, fat storage
- Red BM: Active, RBC production
Types of cells in Red Bone Marrow
- Hematopoietic cells
- Stromal cells
- Hematopoietic Stem cells
Stromal Cells
Structural support, Signaling, and Control of hematopoietic cell maturation
Hematopoietic Stem Cells (HSC)
- Self-renewing
- Some remain stem cells & others form differentiated cells (multipotent)
- No specific morphology other than surface markers
Surface markers of HSC
- CD34: Cluster Differentiation, cell migration/adhesion regulator that may help SC bind marrow matrix.
- C-Kit: RTK which binds Stem cell factor
Start of Hematopoiesis
1) LT-HSC
2) ST-HSC
3) MPP-multipotent progenitor
What are the 2 paths that can be taken from MPP cells
- Common Lymphoid Progenitor
- Common Myeloid Progenitor
Common Lymphoid Progenitor differentiation
- T-Progenitor
- B-Progenitor
- Natural Killer Progenitor
Common Myeloid Progenitor differentiation
- Granulocyte-monocyte Progenitor
- Megakaryocyte-erythroid Progenitor
Chemokines
Small signaling proteins which direct immune/stem cells to sites where they are needed
Niche
Area in which Stem cells are present in an undifferentiated state and a self-renewable state
2 Types of Asymmetry
- Divisional: only a certain type of cells divide
- Environmental: Some niches produce specific types of cells
Erythropoiesis
Development of mature RBCs from erythropoietic stem cells
Information on Erythropoiesis
- 7-10 days
- Occurs in Erythropoietic islands
- From Myeloid lineage (proerythroblasts)
Formation of RBC stages
HSC
Proerythroblast
Basophilic Erythroblast
Polychromatic Erythroblast
Orthochromatic Erythroblast
Reticulocyte
Erythrocyte (Mature Red Blood Cell)
What regulates Erythropoiesis and where is it produced?
Erythropoietin
(Kidney cortex Peritubular interstitial fibroblast-like cells)
How exactly is Erythropoietin produced
Low O2 in Kidney signals using Hypoxia Inducible Factor (HIF) , producing EPO
Thrombopoiesis
Formation of Platelets from same myeloid path.
Promegakaryocytes, Megakaryocytes, Thrombocytes (platelets)
Megakaryocyes
- Very large 60 um
- Lots of duplicated DNA
- Reduplication without mitosis
- Processes extend into blood vessels and disintegrate to form Platelets
What regulates Thrombopoiesis?
Thrombopoietin
(Liver, sometimes Kidney)
What do Granulocyte-Macrophage progenitors differentiate to?
- Monocytes
- Macrophages
- Dendritic cells
- Osteoclasts
Hematocrit M/F
Volume percentage of RBC in the blood
- M: 0.40 - 0.52
-F: 0.37 - 0.48
Hemoglobin M/F
- M: 160 - 170 g/L
- F: 135 - 145 g/L
RBC count
4.5 - 5 Million / uL
Platelet count
150,000 - 300,000 / uL
WBC count
7000 / uL
- N: 4000 / uL
- E: 200 / uL
- B: 50 / uL
- Mono: 500 / uL
- Lymph: 2000 / uL
A vs B antigen
- A: N-acetyl-Galactosamine
- B: Galactose
What does RH+ mean?
It has a D antigen also present on RBC
You only get this by Immunization
Blood groups and Antigens
- A: A, H
- B: B, H
- AB: A & B, H
- O: H
Can also have D if RH+
What happens in Platelet Activation
1) GP-VI binds collagen
2) Tyrosine Phosphorylation Cascade
3) PLC act.
4) IP3 causes Ca2+ Release
Platelet activation factor (PAF)
- Produced by Leukocytes
- a2-R (Gi)
- cAMP drops
- Ca2+ increases (activation)
What Glycoproteins attach Platelets to Collagen
- GP-VI
- GP-Ia
- GP-IIa
What Glycoproteins attach Platelet and vWF
GP-Ib-IX-V
What Glycoproteins attach Platelet to Fibrinogen in Platelet aggregation
- GP-IIIa
- GP-IIb
Arg-Gly-Asp domain
What is other name for Tissue Factor
Factor III
What is FXIIIa
a Transglutaminase
What activates TFPI as a Negative feedback?
FXa
What can be used in Vitro anticoagulants to reduce Ca2+
- EDTA
- Na-Citrate
- Na-Oxalate