Myeloid tissue trans
Myeloid tissue
Is the bone marrow
Why we discuss myeloid tissue/bone marrow? – because we want to study the development of blood cells. We called it HEMOPOEISIS/HEMATOPEISIS
HEMOPEISIS/HEMATOPOEISIS –Blood cell formation (occurs in the bone group)
Why study this? Because: there is a continuous replacement of cells they have short life span when they are in the peripheral circulation so, we have to study how these cells mature and differentiate
Phases of hematopoeisis
MESOBLASTIC PHASE (Prehepatic or primordial phase) hemopoeisis starts in utero and the development of which in utero at first starts at Yolk Sac
The blood cells in utero are formed from the yolk sac
So in the development, the yolk sac degenerates
By 3rd week of embryonic development
HEAPTIC PHASE (Hepatosplenothymic phase)
From the yolk sac, it is transferred to the liver
The formation will occur in the liver
Other books also called it “hepatosplenothymic phase” because it also includes the spleen and the thymus
By 6th week of development
MYELOID PHASE (Medulo Lymphatic Phase)
When the bone cells are formed – the medullary cavities of the long bone are fromed- then, the formation will now occur in the bone marrow
By 3rd Month of development
What happens then is that you formed your bone marrow
So at BIRTH, all the medullary cavities that are formed are all RED MARROW
As you grow at the age of 6 y/o, you start replacing the red marrow with YELLOW MARROW
So when you the age of 10, most of the red marrow is replaced by yellow marrow except:
Sternum
Ribs
Vertebra
Pelvic bones
Epiphysis of the long bones
So this are the sites of hemopoeisis in adults
Bone marrow aspiration –usually taken from the pelvic
So these are now the sites of red marrow
Types:
Red Marrow
Active in hemopoeisis
Yellow Marrow
Inactive during hemopoeisis because it consist of adipose in cases of emergencies, some authors believe that this yellow marrow could be reverted back
Is the bone marrow
Why we discuss myeloid tissue/bone marrow? – because we want to study the development of blood cells. We called it HEMOPOEISIS/HEMATOPEISIS
HEMOPEISIS/HEMATOPOEISIS –Blood cell formation (occurs in the bone group)
Why study this? Because: there is a continuous replacement of cells they have short life span when they are in the peripheral circulation so, we have to study how these cells mature and differentiate
Phases of hematopoeisis
MESOBLASTIC PHASE (Prehepatic or primordial phase) hemopoeisis starts in utero and the development of which in utero at first starts at Yolk Sac
The blood cells in utero are formed from the yolk sac
So in the development, the yolk sac degenerates
By 3rd week of embryonic development
HEAPTIC PHASE (Hepatosplenothymic phase)
From the yolk sac, it is transferred to the liver
The formation will occur in the liver
Other books also called it “hepatosplenothymic phase” because it also includes the spleen and the thymus
By 6th week of development
MYELOID PHASE (Medulo Lymphatic Phase)
When the bone cells are formed – the medullary cavities of the long bone are fromed- then, the formation will now occur in the bone marrow
By 3rd Month of development
What happens then is that you formed your bone marrow
So at BIRTH, all the medullary cavities that are formed are all RED MARROW
As you grow at the age of 6 y/o, you start replacing the red marrow with YELLOW MARROW
So when you the age of 10, most of the red marrow is replaced by yellow marrow except:
Sternum
Ribs
Vertebra
Pelvic bones
Epiphysis of the long bones
So this are the sites of hemopoeisis in adults
Bone marrow aspiration –usually taken from the pelvic
So these are now the sites of red marrow
Types:
Red Marrow
Active in hemopoeisis
Yellow Marrow
Inactive during hemopoeisis because it consist of adipose in cases of emergencies, some authors believe that this yellow marrow could be reverted back