6.1 Flashcards
define Hematopoiesis
formation of blood cells and how they get into the circulation
RBC count
male: 4.5-5.5 milion/microL
female: 3.9-5.3 milion/microL
Platelets count
2.5-3 x 10^5 /microL
WBC count
3,000-12,000 /microL
WBC components count
N: 60-70% L: 25-30% M: 4-8% E: 2-4% B: 0-1%
what are the two forms of Hematopoiesis
constituitive
stress
define constituitive Hematopoiesis
daily production to maintain steady levels
10^11 cells producrd per day
(25% RBC, 75% WBC)
define stress Hematopoiesis
induced by event (anemia, infection)
where does Hematopoiesis take place?
Liver of Fetus
Axial skeleton after birth
what are the different components of bone marrow?
yellow- inactive
red- active
active bone marrow contains which cells?
Hematopoietic cells
Hematopoietic stem cells
Stromal cells
job of Stromal cells?
structual support
signalling
control of Hematopoietic cell maturation
Describe Hematopoietic stem cells?
self renewing
multipotent
assymetricc division
2 important surface markers of Hematopoietic stem cells?
c-Kit
CD34
what is c-Kit?
receptor Tyrosine-Kinase which binds “stem cell factor”
like kit-kat choclate. when you eat it it marks you with choclate
what is CD34
cells adhesion regulator. can help stem cells bind to marrow matrix and stromal cells
(like a CD record. you put it inside the radio to make music that adhers to you. i know its bad)
how does Hematopoiesis begin?
HSC differentiate from omnipotent to oligopotent
than to unipotent
what are the two pathways for multipotent progenitor cells?
- Lymphoid (become Lymphocytes or Natural killer cells)
2. Myeloid (become Erythrocytes. Platelets, Granulocytes, Monocytes or Mast cells)
what factors are responsible for maturation?
cytokines
cell-to-cell contact
surrounding environment
hormones
how do Cytokines responsible for maturation?
glycoproteins that induce transcription via Tyrosine-kinase
pathway for RBC formation
Myeloid stem cell -> progenitor cell -> proerythroblast -> early erythroblast -> polychromatophilic erythroblast -> orthochromatophilic erythroblast -> reticulocyte -> eryithrocyte
what regulates RBC formation?
Erythropoietin (produced by kidney)
describe the production of Erythropoietin
low O2 in kidney -> HIF activation -> increased transcription of Erythropoietin
pathway for Platelets formation
Myeloid stem cell -> progenitor cell -> megakaryoblast -> thrombopoietin promegakaryocyte -> thrombopoietin megakaryocyte -> thrombopoietin platelets
