Lecture 7 Flashcards
(89 cards)
With in the first two weeks of embryonic life what blood cell is produced by the yolk sac?
Primitive red cell
What type of WBC is produsted 1st?
Granulocytes
What is the 1st major stage of Hematopoietic Development?
Mesoblastic Period (Yolk Sac Phase)
What is the 2nd major stage of Hematopoietic Development?
Hapatic Period
What is the 3rd major stage of Hematopoietic Development?
Medullary (Myeloid Phase AKA Bone Marrow)
When does the Mesoblastic Period begin?
Around the 19th day of embryologic development.
When doe the Mesoblastic Period end?
Around 8 weeks (or 2 months) of gestation.
What are the Hematopoietic products produced during the Mesoblastic Period?
- Portlans
- Gower 1
- Gower 2 HgBs
When the the Hepatic Period usually start?
Begins at 4-5 weeks of gestation.
How long does the Hepatic Period last?
It ends just before birth.
Where does the Hepatic Period take place?
Liver
Where does the Mesoblastic Period take place?
THe Yolk Sac
What are the Hematopoictic products produced during the Hepatic Period?
- Primitive and definitive erythoblasts
- Granulocytes, monocytes, lymphocytes, megakaryocytes
- Hemoglobins F, A, and A2
What other tissue produces blood cells during the Hepatic Period besides the Liver?
Spleen
What Period is 1?

Mesoblastic
What Period is 2?

Hepatic
What Period is 3?

Medullary
Where does 1 take place?

Yolk Sac
Where does 2 take place?

Liver & Spleen
Where does 3 take place?

Boan Marrow
When does the Medullary Phase begin?
Usually begins between the 4th and 5th month of fetal gestation.
Where does the Medullary (Myeloid) Phase take place?
In the the medulla or inner part of the bone marrow.
When does the bone marrow become the primary site of hematopoiesis?
By the sixth month of age.
What Hematopoietic products produced at this time?
- Various stages of all cell lines
- EPO: Erythropoietin
- Fetal and adult hemoglobins




