Hematopoiesis

Hematopoiesis is the process of blood cell formation. The sites with dates and cell lines are: Yolk sac - around week two of gestation, where mesodermal cells congregate to form blood cell clusters; Intra-embryonic sites - liver and spleen, starting from week six of gestation, where hematopoietic stem cells migrate and differentiate into blood cells.

The text mentions the germinal stage, which is the first two weeks after conception; the embryonic period, which spans from the third through the eighth week after conception; and the fetal period, which extends from the ninth week until birth.

Vasculogenesis is the de novo formation of blood vessels from mesodermal precursor cells. Angiogenesis is the formation of new blood vessels from pre-existing vessels. Types of vasculogenesis and angiogenesis are not mentioned in the text. The sites for vasculogenesis and angiogenesis are not specified in the given text.

<p>Extra-embryonic hematopoiesis, which is the formation of blood cells outside of the embryo, precedes intra-embryonic blood cell development. This process provides an early source of blood cells before the intra-embryonic sites such as the liver and spleen become functional for hematopoiesis.</p> Signup and view all the answers

<p>The text mentions the objective of linking some clinical cases with embryonic explanations, but it does not provide specific clinical cases or their corresponding embryonic explanations.</p> Signup and view all the answers