Erythroposis starts in fetal liver during ?
a) 2-4 weeks
b) 4-6 weeks
c) 6-8 weeks
d) 8-10 weeks
Correct Answer - C
Ans. is ‘c’ i.e., 6-8 weeks
Developmental hematopoiesis occurs in three anatomic stages:?
- Mesoblastic
- Hepatic
- Myeloid
Mesoblastic hematopoiesis occurs in extraembryonic structures,
principally in the yolk sac, and begins between the 10th and 14th
days of gestation.
By 6-8 wk of gestation the liver replaces the yolk sac as the primary
site of blood cell production, and by 10-12 wk extraembryonic
hematopoiesis has essentially ceased.
Hepatic hematopoiesis occurs in the liver throughout the remainder
of gestation, although production begins to diminish during the
second trimester as bone marrow (myeloid) hematopoiesis
increases.
The liver remains the predominant hematopoietic organ through wk
20-24 of gestation