Bone Marrow and Blood Cells Flashcards
Where does haemopoiesis take place in a 0-2 month old foetus?
The yolk sac
Where does haemopoiesis take place in a 2-5 month old foetus?
Liver and spleen
Where does haemopoiesis take place in a 5-9 month old foetus?
Bone marrow
Where does haemopoiesis take place after birth?
Bone marrow
In the bone marrow of which bones does haemopoiesis take place in infants?
Most bones
In the bone marrow of which bones does haemopoiesis take place in adults?
Vertebrae
Ribs
Sternum
Sacrum and pelvis
Proximal end of femur
What is bone marrow?
Soft, spongy, gelatinous tissue found in the hollow space in the interior of bones
What does bone marrow consist of?
Stem cells supported by stroma
What is produced in bone marrow?
Red blood cells
Platelets
Most white blood cells
What are the two different types of bone marrow?
Red marrow
Yellow marrow
What tissue is the main constituent of red marrow?
Haemopoietic tissue
What tissue is the main constituent of yellow marrow?
Fatty tissue
All marrow is what type at birth?
Red marrow
What proportion of marrow is red marrow in adulthood?
Half
What happens to half of the bodies red marrow between birth and adulthood?
It is converted to yellow marrow
How can bone marrow be examined histologically?
By taking a trephine biopsy of the marrow in the pelvis
What is the starting cell for haemopoiesis?
Multipotent haemopoietic stem cell
What cells can a multipotent haemopoietic stem cell become differentiate into?
Common myeloid progenitor
Common lymphoid progenitor
A common myeloid progenitor cell can eventually differentiate into which mature blood cells?
Platelets
Erythrocytes (RBC)
Mast cell
Basophil
Neutrophil
Eosinophil
Macrophage
Under the influence of what hormone does a common myeloid progenitor cell begin differentiating to platelets?
Thrombopoietin
Thrombopoietin causes common myeloid cells to differentiate into which cell initially?
Megakaryocytes
How do megakaryocytes become platelets?
Increase in size
Replicate DNA
Platelets bud from cytoplasm
What causes megakaryocytes to produce platelets?
Thrombopoietin
What causes common myeloid progenitor cells to differentiate into red blood cells?
Erythropoietin