Bone marrow nonneoplastic
General
Embryonic development
Author: Nat Pernick, M.D.
Last author update: 1 December 2006
Last staff update: 11 July 2019
Copyright: 2002-2019, PathologyOutlines.com, Inc.
PubMed Search: Embryonic development [title] bone marrow
Table of Contents
Definition / general | Diagrams / tables | Microscopic (histologic) images | Additional referencesCite this page: Pernick N. Embryonic development. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/bonemarrowembryonic.html. Accessed January 10th, 2025.
Definition / general
- In embryo, hematopoiesis (other than lymphoid) occurs in yolk sac with formation of mesenchymal derived primitive erythroblasts
- Aorta also contributes lymphomyeloid stem cells, as do embryonic liver and bone marrow (Development 2002;129:4147, Ann N Y Acad Sci 2005;1044:41)
- At weeks 10 to 24, liver is primary hematopoietic organ with production of granulocytes and megakaryocytes in sinusoids
- At months 4 - 5, bone marrow hematopoiesis begins
- By birth, liver and spleen have minimal role in myelopoiesis and bone marrow is major site of hematopoiesis
Diagrams / tables
Images hosted on other servers:
Blood islands in embryo
Microscopic (histologic) images
Images hosted on other servers:
Yolk sac at 18 days
Fetal liver at 17 weeks
Fetal bone marrow at 19 weeks
Additional references
