what is PHSC and genesis of RBCs

2. TOPIC;
Genesis of RBCs
BY
RONIT KUMAR
Student of cop, JPMC

3. What is pluripotential hematopiotic stem cell?
•PHSC cells are primitive cells in bone
marrow which give rise to all blood cells.
•They are rounded in shape.
•PHSC are found in bone marrow of adults.

4. Genesis of blood cells
• Pluripotential hematopoietic stem cell;
From which all the cells of the circulating
blood are eventually derived.
. Successive divisions of the pluripotential cells to from the
different circulating blood cells.
. A small portion of them remains pluripotential cells and is
retained in the bone marrow to maintain a supply of these.
. The reproduced cells, differentiate to form the other cell
types.

5. Genesis of blood cells
• The intermediate stage cells are very much like the
pluripotential stem cells, even though they have already become
committed to a particular line of cells and are called
commited stem cells.
• The different commited stem cells, will produce colonies of
specific types of blood cells.
• A committed stem cell produces erythrocytes is called a
Colony-forming unit-erythrocyte, and the abbreviation
CFU-E is used to designate this type of stem cell.

6. Genesis of blood cells
•Growth and reproduction of the different stem cells;
are controlled by multiple proteins called Growth
inducers.one of the these , interleukin-3, promotes growth and
reproduction of virtually all the different types of committed stem
cells.
. The growth inducers promote growth but not differentiation of
the cells.
. Another set of proteins called differentiation inducers.each of
these causes one type of committed stem cell to differentiate one
or more steps towards a final adult blood cell.

8. Stages of differentiation of RBCs
•Proerythroblast (MEGALOBLAST);
proerythroblast is the first cell derived from
CFU-E.
. It is very large in size, with diameter of 20 micron.
. Its nucleus is very large and accupies the cell almost
completely.
. Proerythroblast does not contain hemoglobin.
. Cytoplasm is basophilic in nature.
. Proerythroblast divides multiple times and forms cell of next
stage called BASOPHILIC ERYTHROBLAST.

9. Basophilic erythroblast(Early
normoblast);
• It is smaller than proerythroblast.
• Diameter of about 15 micron.
• In the nucleus nucleoli disappears.
• Condensation of chromatin network occurs, the
condensed network becomes dense.
• Cytoplasm is basophilic in nature so thats why it is
called basophilic erythroblast.
• The cell develops into next stage called POLY
CHROMATIC ERYTHROBLAST.

10. Polychromatic erythroblast(intermediate
normoblast);
• Cell is smaller than basophilic erythroblast.
• Diameter of 10 to 12 micron.
• The nucleus is still present, chromatin network
shows further condensation.
• The hemoglobin starts appearing.
• The cell develpos into next stage called
ORTHROCHROMATIC ERYTHROBLAST.

11. ORTHROCHROMATIC ERYTHROBLAST;

12. RETICULOCYTE;
• It is slightly larger than mature RBC.
• The cytoplasm contains reticular networks which are
formed by remnants of organelles due to the reticular
network the cell is called Reticulocyte.
• During this stage cell enters in the blood cappilaries from
the site of production by diapedsis.
• Reticular network disappears and cell becomes MATURE
ERYTHROCYTE.

13. MATURE ERYTHROCYTE;
• It has biconcave shape.
• it has a diameter of 7.2 micron.
• The mature RBC have hemoglobin.
• it lacks nucleus.
• it requires 7 days for development and maturation of RBC
from proerythroblast.