Human Health Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Congenital Anomaly Research Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Anat Rec (Hoboken). 2019 Dec;302(12):2211-2223. doi: 10.1002/ar.24226. Epub 2019 Jul 25.
Formation of the skeletal structure in the human embryo has important consequences in terms of support, protection, and function of organs and other systems. We aimed to describe the formation of the rib cage during the embryonic period, in order to detect prominent features and identify the possible factors affecting rib cage morphology. We employed high-resolution digitized imaging data (n = 34) obtained in human embryos with Carnegie stage (CS) between 17 and 23. The rib cage became detectable as cartilage formation at CS17, expanding outward from the dorsal side of the chest-abdominal region. Ribs elongated progressively to surround the chest, differentiating into the upper and lower rib cage regions by CS20. The ends of corresponding ribs in the upper region elongated toward each other, leading to their joining and sternum formation between CS21 and CS23, while the lower region of the rib cage remained widely open. The rib cage area with the largest width shifted from the 5th rib pair at CS17 to the 9th pair at CS23. The depth of the rib cage was similar across the upper region at CS17, with the major portion remaining in the middle part after CS20. The heart was located beneath the rib pairs providing the largest depth, while the liver was located beneath the rib pairs providing the largest width. Formation of the sternum, development of spinal kyphosis, and organization of larger internal organs within the thoracic and abdominal cavity are possible factors affecting rib cage morphology. Anat Rec, 302:2211-2223, 2019. © 2019 American Association for Anatomy.
人体胚胎骨骼结构的形成对器官和其他系统的支撑、保护和功能具有重要意义。我们旨在描述胚胎期胸廓的形成，以发现突出的特征，并确定可能影响胸廓形态的因素。我们使用了在卡内基阶段（CS）17 至 23 之间的人类胚胎中获得的高分辨率数字化成像数据（n = 34）。在 CS17 时，胸廓开始作为软骨形成而变得可检测，从胸腹部的背侧向外扩展。肋骨逐渐延长以环绕胸部，到 CS20 时分化为上、下胸廓区域。上区域相应肋骨的末端相互伸长，导致它们在 CS21 和 CS23 之间连接并形成胸骨，而下胸廓区域仍然广泛开放。肋骨区域的最大宽度从 CS17 的第 5 对肋骨转移到 CS23 的第 9 对肋骨。CS17 时，上区域的肋骨深度相似，CS20 后大部分仍在中部。心脏位于提供最大深度的肋骨对下方，而肝脏位于提供最大宽度的肋骨对下方。胸骨的形成、脊柱后凸的发展以及胸腹腔内较大内脏器官的组织可能是影响胸廓形态的因素。解剖学记录，302：2211-2223，2019。©2019 年美国解剖学会。
