2. HEMATOPOIESIS PART 1 Flashcards
It is a continuous and regulated process of blood cell production that includes cell renewal, proliferation, differentiation, and maturation.
hematopoiesis
organs involved in hematopoieis
bone marrow, liver, spleen, lymph nodes, thymus
stages of hematopoiesis
mesoblastic, hepatic, myeloid
when does mesoblastic phase begin?
19th day of gestation
what type of hematopoiesis happens in the mesoblastic period?
primitive hematopoiesis
in the mesoblastic stage, cells from the mesoderm migrate in these two locations:
yolk sac, aorta-gonad mesonephros
cells from the mesoderm that migrate to the central cavity of the yolk sac form into?
primitive erythroblasts
cells from the mesoderm that surround the cavity of the yolk sac form into?
angioblasts
angioblasts will eventually form what structures
blood vessels
cells from the mesoderm that migrate to the aorta-gonad mesonephros region will form?
hematopoietic stem cells
what is the purpose of primary erythroblasts?
produce hemoglobin needed for delivery of oxygen to rapidly developing embryonic tissues
embryonic hemoglobins
gower 1, gower 2, portland
yolk sac hematopoiesis is (intra/extravascular)?
intravascular
start of the hepatic stage of hematopoiesis
5th to 7th week of gestation
this marks the definitive stage of hematopoiesis
hepatic stage
the stage of hematopoiesis that is marked by the presence of recognizable developing erythroblasts, granulocytes, monocyte
hepatic phase
first fully developed organ in the hepatic stage; major site of T cell production
thymus
the site of b cell production in the hepatic stage
kidney and spleen
will gradually decrease granulocyte production and starts to mainly focus on lymphopoiesis during the hepatic stage
spleen
the predominant hemoglobin in the hepatic stage
Hb F
hepatic hematopoiesis is (intra/extravascular)?
extravascular
it is when medullary hematopoiesis begins
5th month of gestation
site of myeloid hematopoiesis
bone marrow
in medullary hematopoiesis, these cells begin to migrate into the core of the bone
HSCs, mesenchymal cells
these cells continue to proceed with hematopoiesis as they migrate to the bone marrow
Hematopoietic stem cells
in the myeloid stage of hematopoiesis, these cells differentiate into stromal cells
mesenchymal cells
it is the week where the bone marrow becomes the primary site of hematopoiesis
end of the 24th week gestation
it is the week where the bone marrow becomes the only normal site of blood cell production
3 weeks postpartum onwards
specific medullary hematopoietic sites in children
skull, clavicle, sternum, ribs, vertebrae, pelvis, long bones of arms & legs
specific medullary hematopoietic sites in adults
flat bone only: skull, clavicle, sternum, ribs, vertebrae, pelvis, proximal ends of long bones of arms & legs
percentage of hemoglobin in neonates in myeloid hematopoiesis
Hb F (60-80%)
Hb A (20-40%)
percentage of hemoglobin in adults in myeloid hematopoiesis
Hb A1 (>95%)
Hb A2 (1.5-3%)
Hb F (<1/2%)
the myeloid to erythroid ration in the medullary phase
3:1/4:1
These five are within measurable levels during myeloid phase.
EPO
G-CSF
GM-CSF
Hb F
Hb A
The counterpart of fetal hepatic period in infants is the ________________ in adults
extramedullary hematopoiesis
it is where extramedullary hematopoiesis
liver, spleen
contains developing erythroid, myeloid, megakaryocytic, and lymphoid cells
bone marrow
consists of the bone marrow and thymus and is where T and B lymphocytes are derived
primary lymphoid tissue
where lymphoid cells respond to foreign antigens
secondary lymphoid tissue
secondary lymphoid organs
MALT, lymph nodes, spleen
two major components of the bone marrow
red marrow, yellow marrow
hematopoietically active marrow
red marrow