T3 hematopoiesis

hematopoiesis

production and development of all blood cells

erythropoiesis

production of RBCs

leukopoiesis

production of WBCs

thrombopoiesis

production of platelets

phases of hematopoiesis

mesoblastic, hepatic, myeloid

mesoblastic period - location

yolk sac

hepatic period - location

liver, spleen, lymph nodes

myeloid period - location

bone marrow

extramedullary hematopoiesis - what is it

blood production outside the bone marrow

extramedullary hematopoiesis - occurs when

bone marrow function fails

bone marrow - types

red & yellow

red bone marrow

active site of blood cell production

yellow bone marrow

fat storage

B cells - produce where

bone marrow

B cells - mature where

bone marrow

T cells - produce where

bone marrow

T cells - mature where

thymus

hypercellular bone marrow

blood cells > fat cells

hypocellular bone marrow

blood cells < fat cells

normocellular bone marrow

blood cells = fat cells

myeloid : erythroid ratio

ratio of granulocytes + monocytes to red blood cell precursors

myeloid : erythroid - normal value

3:1

hematopoietic stem cells

immature cells capable of developing into all types of blood cells

stem cells divide to…

1 self-renewing stem cell & 1 differentiating cell

totipotent stem cells

can form all body cells & supporting membranes

pluripotent stem cells

can differentiate to many but not all cell types

erythropoiesis - stages

pronormoblast, basophilic normoblast, polychromatic normoblast, orthochromatic normoblast, polychromatic erythrocyte (reticulocyte), erythrocyte

erythropoiesis - change in cells

size decrease, nucleus loss, accumulate Hb, change staining characteristics

erythropoiesis - bone marrow - stages

pronormoblast, basophilic normoblast, polychromatic normoblast, orthochromatic normoblast

erythropoiesis - bloodstream - stages

polychromatic erythrocyte (reticulocyte), erythrocyte

erythropoiesis - nucleoli gone at what stage

polychromatic normoblast

erythropoiesis - nucleus gone at what stage

polychromasia (reticulocyte)

erythropoiesis - cytoplasm changes

blue → pink-gray & becomes biconcave, central pallor

erythropoiesis - deeply basophilic blue cytoplasm

intense RNA activity for Hb production

erythropoiesis - pink cytoplasm

Hb production can be seen

granulocytopoiesis - stages

myeloblast, promyelocyte, myelocyte, metamyelocyte, band form, mature segmented granulocyte

granulocytopoiesis - nucleoli gone at what stage

myelocyte

myeloblast - cytoplasm

auer’s rod

promyelocyte - cytoplasm

azurophilic granules

myelocyte - key

specific granules appear → neutrophilic, eosinophilic, basophilic

myelocyte - cytoplasm

azurophilic and specific granules visible, golgi region present

metamyelocyte - nucleus

kidney-shaped, acentric

band form - nucleus

horseshoe-shaped, acentric, specific for neutrophils

mature segmented granulocyte

ready for immune defense

lymphocytopoiesis - stages

lymphoblast, prolymphocyte, lymphocyte

lymphoblast - nucleus

large, round, thin loose chromatin, 1-2 nucleoli

prolymphocyte - nucleus

intermediate chromatin with some clumping, 0-1 nucleoli

monocytopoiesis - stages

monoblast, promonocyte, immature monocyte, monocyte

megakaryopoiesis - stages

megakaryoblast, megakaryocyte, platelets

megakaryoblast - nucleus

round/oval, central/eccentric, red-purple, fine and distinct chromatin, 2-6 nucleoli

megakaryoblast - cytoplasm

basophilic (blue), pseudopodia, no granules

megakaryocyte - nucleus

large lobulated nucleus, purple with granular chromatin, no nucleoli

megakaryocyte - cytoplasm

pinkish-blue, occasional pseudopodia

myeloid stem cell - lineages

- Erythrocytes (RBCs)
- Megakaryocytes → Platelets
- Granulocytes (neutrophils, eosinophils, basophils)
- Monocytes → Macrophages

lymphoid stem cell - lineages

- B lymphocytes (B cells)
- T lymphocytes (T cells)
- Natural Killer (NK) cells)