Morphogenesis of the Manubrium of Sternum in Human Embryos: A New Concept

Authors

  • José Francisco Rodríguez-Vázquez,

    Corresponding author
    1. Department of Anatomy and Human Embryology II, Faculty of Medicine, Complutense University, Madrid, Spain
    • Departamento de Anatomía y Embriología Humana II, Facultad de Medicina, Universidad Complutense, E-28040 Madrid, Spain
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    • Fax: +34(9)13947187

  • Samuel Verdugo-López,

    1. Department of Anatomy and Human Embryology II, Faculty of Medicine, Complutense University, Madrid, Spain
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  • Jose Manuel Garrido,

    1. Department of Anatomy and Human Embryology II, Faculty of Medicine, Complutense University, Madrid, Spain
    2. Department of Cardiac Surgery, Ramon y Cajal Hospital. Madrid, Spain
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  • Gen Murakami,

    1. Division of Internal Medicine, Iwamizawa Kojin-kai Hospital, Iwamizawa, Japan
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  • Ji Hyun Kim

    1. Department of Anatomy, Chonbuk National University School of Medicine, Jeonju, Korea
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  • This article was published online on 19 November 2012. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 29 November 2012.

Abstract

To revisit many theories on fetal development of the manubrium of the sternum, we examined 25 mid-term fetuses at 6–9 weeks of gestation. The initial developmental stage of the manubrium was characterized by a distinct interclavicular mesenchyme that was continuous with the developing clavicles. Because parts of the clavicle in which endochondral ossification occurs originate from the neural crest, the interclavicular mesenchyme seems to be of the same origin. The sternal bands, possibly of the lateral plate origin, were restricted at the anterior ends of the ribs in the paired thoracic walls. The interclavicular mesenchyme extended caudally and laterally to reach the anterior ends of the first ribs, and thus the interclavicular mesenchyme expanded into the intercostoclavicular mesenchyme. Then, the primitive manubrium was delimited by the sternoclavicular joint and its related ligaments, all of which developed from the interclavicular and intercostoclavicular mesenchymes. Although the first ribs were attached to the intercostoclavicular mesenchyme, the former was vimentin-negative in contrast to the latter, positive mesenchyme. Soon afterwards, the small upper end of the sternal bands was integrated into the intercostoclavicular mesenchyme to form the primitive manubrium. The infrahyoid muscles and their supplying nerves maintained a close topographical relation to the interclavicular or intercostoclavicular mesenchyme, whereas the pectoralis major muscle kept attachments to the sternal bands. Consequently, the manubrium of sternum appeared to develop in a complex way at a junction area between derivatives of the neural crest, lateral plate, and somite. Anat Rec, 2013. © 2012 Wiley Periodicals, Inc.

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