Open AccessMORPHOLOGIC and RADIOLOGICAL OBSERVATIONS ON THE EARLIEST BONE MARROW FORMATION IN HUMAN EMBRYOS and FETUSES
Author(s) -
Enzan Hideaki,
Haea Hiroshi,
Izumi Takaki,
Ohkita Takeshi
Publication year - 1983
Publication title -
acta patholigica japonica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 74
ISSN - 0001-6632
DOI - 10.1111/j.1440-1827.1983.tb00351.x
Subject(s) - intramembranous ossification , ossification , pathology , fetus , bone marrow , anatomy , clavicle , diaphysis , mandible (arthropod mouthpart) , mononuclear phagocyte system , maxilla , medicine , biology , femur , pregnancy , surgery , genetics , botany , genus
Morphologic and radiologic studies were undertaken on 26 human embryos and fetuses to determine the stage and site of the earliest bone marrow formation. Up to the 10th week of gestation, primary bone marrow is not present anywhere although the intramembranous ossification occurs in the maxilla and mandible and also in the middle portion of the clavicle. At the 11th week of gestation, X‐ray examination showed in two fetuses the bone formation in the clavicle, scapula, maxilla, mandible, and the diaphysis of the long bones. Serial sections of these fetuses revealed that the primary bone marrow occurs first in the middle portion of the clavicle. From a series of our embryological studies, the concept of the mononuclear phagocyte system which involves the bone‐marrow‐derived monocytic origin of tissue macrophages, is not accepted, at least, on the origin of Kupffer cells in human fetal livers.