Hemo ch.4
Hematopoietic cells three phases of cell maturity
1 primitive, multipotential cell, 2 intermediate cell, 3 mature cell
extramedullary hematopoiesis occurs when
1. bone marrow becomes dysfunctional (leukemia), 2. bone marrow is unable to meet demands placed on it, as it is in the hemolytic anemias
Hematopoiesis system consists of
Bone marrow, liver, spleen, lymph node and thymus
the foundation of adult hematopoietic system
Hematopoietic STEM cells (HSC)
human stem cells
Totipotential, Pluripotential, multipotential
Multipotential stem cells are found in
adults, but they are limited to specific types of cells to form tissues. Ex: bone marrow stem cells can produce all types of blood cells, bone cartilage, and adipose (fat) cells
red bone marrow is initially found in both
appendicular and axial skeleton
in adults the red bone marrow becomes confined to
axial skeleton and proximal ends of long bones
Hematopoietic cells are compartmentalized in the
cords
produces the first adult repopulating HSC
embryo
Multipotent adult progenitor cells expressed in enzyme... prevents cell from aging
enzyme telomerase
Embryonic blood cells
excluding lymphocyte types of WBC, originate from the mesenchymal tissue
after the ........., the bone marrow begins to assume its ultimate role as the primary site of hematopoiesis
fifth fetal month
Totipotential stem cell are present within
first few hours after ovum is fertilized
during the ....... the bone marrow begins to function in the production of blood cells
fourth month
the onset of circulation between the yolk sac and embryo proper confounds the precise determination of
hematopoietic sources
yellow marrow
inactive and composed of mostly fat (adipose) tissue
master cells
inside bone marrow capable of rebuilding almost any damaged tissue... also called Multipotent adult progenitor cell (MAPC)
group consist of committed progenitors cells destined to develop into distinct cell lines
intermediate cell
Pluripotential stem cell can develop
into any human cell, except they cannot develop into a fetus
gradually ........ becomes the site of blood cell development
liver
secondary ontogenic sites of heatopoiesis
liver and bone marrow
blood, brain etc have specialized stem cells capable of
making replacement cells
most developed group with specific functions
mature cell
Totipotential stem cell are and can develop
most versatile, can develop into any human cell, including embryo into fetus.
progenitor of all blood cells is called
multipotential hematopoietic stem cell
red marrow
normally active in production of leukocytes, erythrocytes and thrombocytes
bone marrow is...... and is found
one of the body's largest organ.... found within the cavities of all bones
is the first in the sequence of steps of hematopoietic cell generation and maturation
pluripotent stem cell
first blood cells are... and formed during the first...
primitive red blood cells (erythroblast)... formed during the first 2 to 8 weeks of life
most immature group capable of self-renewal and differentiation into all blood cell lines
primitive, multipotential cell
erythropoiesis
process of red blood cell (erythrocyte) production
Pluripotential stem cell are present within
several days after fertilization
extramedullary hematopoiesis
spleen, liver and lymph node revert back to producing immature blood cells ( due to this there is enlargement of spleen and liver)
have the capacity for self-renewal as well as proliferation and differentiation into progenitor cells
stem cells
stem cell plasticity
stem cells adaptable and able to generate an assortment of unrelated types of cells
mesoderm
the embryonic germ layer
Mesenchymal stem/progenitor cells and HSC circulate together in ...... during the ......
the peripheral blood... during the first trimester
Hematopoiesis
the process of blood cell production, differentiation and development
by 18, red marrow is only found in
vertebrae, ribs, sternum, skull bone, pelvis...
first hematopoietic cells are generated in the
yolk sac
sequence of blood cell development
yolk sac-liver/spleen/red bone marrow
