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