Bone Marrow And Hematopoiesis

Front 1

What is hematopoiesis?

Back 1

Blood-cell production

Front 2

Where does hematopoiesis occur?

Back 2

First in the yolk sac, then spleen and liver, finally in the bone marrow

Front 3

What is bone marrow?

Back 3

gelatinous,highly vascular and cellular connective tissue located in marrow cavity of bones

Front 4

What is the function of bone marrow?

Back 4

Formation of blood cells, and delivery of blood cells into circulatory system

Front 5

types of bone marrow

Back 5

Red and yellow

Front 6

Location of yellow bone marrow

Back 6

in long bones of adults

Front 7

Description of yellow bone marrow

Back 7

inflitrated with fat, during childhood replaces red marrow in some sites, in adult not hematopoietic but has potential to do so if necessary

Front 8

Location of red bone marrow

Back 8

epiphyses of long bones as well as flat, irregular short bones (axial skeleton, sternum, areas of skull and vertebrae and certain regions of pelvis)

Front 9

Description of red bone marrow

Back 9

highly vascular, where blood cells differentiate and mature

Front 10

Blood vessels of marrow compartment

Back 10

nutrient artiers, central longitudinal arteries, radial arteries, sinusoids (note lacks lymphatics)

Front 11

Nutrient arteries

Back 11

From the periosteum pass through compact bone to enter the marrow space

Front 12

Central longitudinal arteries

Back 12

formed by the division of the nutrient artyer; they run parallel to the long axis of a bone

Front 13

Radial arteries

Back 13

spoke-like branches that arise form the longitudinal arteries to form sinusoins
enter Volkmann canals and eventually Haversian canals to supply the bone tissue

Front 14

Sinusoids

Back 14

-large
-highly attenuated endothelial lining

Front 15

What in associated with the extravascular surface of sinusoids?

Back 15

reticular fibers and adventitial reticulare cells

Front 16

Where do sinusoids drain?

Back 16

Central longitudinal vien which is drained by veins leavin gbone via the nutrient canal

Front 17

Why don't sinusoids collapse?

Back 17

Veins are smaller then arteries and therefore a high hydrostatic pressure within the sinusoids is developed

Front 18

How do cells enter the sinusoidal lumen?

Back 18

Transcellular. Form migration pores through the endothelial cells

Front 19

What are the compartments in bone marrow?

Back 19

Vascular and hematopoietic

Front 20

Stromal cells in bone marrow

Back 20

macrophages, reticular cells, fibroblasts, and endothelial cells

Front 21

Hematopoietic growth factors

Back 21

Produced and released by endothelial cells, fibroblasts, and other stromal cells

Front 22

Function of macrophones near sinusoid

Back 22

extend processes between endothelial cells into sinusoidal lumen and remove apoptotic cells, residual nuclei from orthochromatic erythroblasts, and particles

Front 23

Function of endothelial cells

Back 23

barrier that prevents immature cells from entering and allow mature one to enter

Front 24

reticular fibers in bone marrow

Back 24

Manufactured by the reticular cells and divide the bone marrow cavity into smaller compartments whicdh are then occupied with cords of hematopoietic cells

Front 25

fat-filled reticular cells in bone marrow

Back 25

recticular cells that have accumulated fat and transform red marrow into yellow marrow

Front 26

glycoproteins in bone marrow

Back 26

fibronectin, laminin and hemonectin
produced by reticular cells

Front 27

Cell associations in red bone marrow

Back 27

-erythroblasts and myelocytes
-orthochromatic erythroblasts and macrophages
-megakaryocytes and sinusoidal wall

Front 28

Mesoblastic Stage of prenatal hematopoiesis

Back 28

-begins at 2 weeks postconception via formation of blood islands
-mesoderm cells become primitive erythroblasts which become nucleated erythrocytes
-NO leukocytes

Front 29

Hepatic and Splenic stage of prenatal hematopoiesis

Back 29

-begins at 6 wks gestaation (liver) or 3 months (spleen)
-erythroblast similar to postnatal
-erythrocytes are still nucleated
-leukocytes begin to develop at 2 months in liver

Front 30

Bone Marrow Stage of prenatal hematopoiesis

Back 30

-Begins at 5 months
-becomes sole producer at birth

Front 31

Stem Cells

Back 31

-self-renewal
-differentiate into multiple cell lineages
-present in circulation and in bone marrow

Front 32

Progenitor cells

Back 32

-committed to single cell lineage (colony forming units)
-proliferate and differentiate into precursor cell
-affected by growth factors
-morphologically indistiguishable forom stem cells

Front 33

Precursor cells

Back 33

-identitable cells in specific lineages

Front 34

CFU-EO

Back 34

progenitor cell that gives rise to: eosinophil

Front 35

CFU-Bas

Back 35

progenitor cell that gives rise to: basophils

Front 36

CFU-GM

Back 36

progenitor cell that gives rise to: neutrophils and monocytes

Front 37

CFU-Meg

Back 37

progenitor cell that gives rise to: megakaryocytes

Front 38

BFU-E

Back 38

slow dividing progenitor cell that gives rise to: erythrocyte

Front 39

CFU-E

Back 39

progenitor cell that gives rise to: erythrocyte

Front 40

Erythropoiesis

Back 40

development of erythrocyte

Front 41

Thrombopoiesis

Back 41

development of platelets

Front 42

Granulopoiesis

Back 42

development of neutrophil, eosinophil and basophil

Front 43

Monopoiesis

Back 43

development of macrophage

Front 44

Progenitor cells in erythropoiesis

Back 44

BFU-E and CFU-E

Front 45

Activity of BFU-E

Back 45

-controlled by unknown regulator but when stimulated high rate of mitotic activity
-normally divides at slow rate
-makes CFU-E

Front 46

Activity of CFU-E

Back 46

-respond to erythropoietin (hormone made by kidney)
-gives rise to proerythroblast