HEMATOPOIESIS

• Hematopoiesis is formed elements of blood.
• It takes place in bone marrow.
• Liver & spleen are the main sites for blood cell formation.

3 main types of mature blood cells-

1. RBC (erythrocytes)
2. WBC (leucocytes)
3. Platelets (thrombocytes)

       BONE MARROW ASPIRATION-

2 methods-

1. Aspiration- Salah bone marrow aspiration needle.
2. Trephine biopsy- jamshidid trephine needle.

• Romanowsky technique used for staining & a stain for iron assess the reticuloendothelial stores of iron.

Most common site for bone marrow biopsy-

1. Infants- tibia (anterior medial area)
2. Adults & children- posterior iliac crest
3. Obese- anterior superior iliac crest

Normal bone marrow counts (myelogram)

• Fat cells : erythroid ratio – 4: 1
• Fat : cell ratio- 1 : 1

Haemotopoietic stem cells (HSC)-

• HSC progenitors originate in bone marrow.

It have 2 types of progenitors-

1. Lymphoid (immune system)- T, B, NK cells
2. Non- lymphoid or myeloid (trilineage stem cells)- granulocytes- monocytes progenitors, erythroid progenitors, megakaryocytes progenitors.

• Pleuripotent HSC is CD34 cells.

Sites of Haemotopoeisis-

• Site of haemotopoiesis is seen on 19^th day (3 weeks) in embryonic life.
• First cell formed is erythrocytes.
• 1 month till birth in liver.

Don’t Forget to Solve all the previous Year Question asked on Haematopoiesis