Switching of the Laryngeal Cavity From the Respiratory Diverticulum to the Vestibular Recess: A Study Using Serial Sagittal Sections of Human Embryos and Fetuses.

摘要: Summary A cecum-like protrusion of the pharynx (the laryngeal cecum or vestibular recess [VR]) develops immediately anterior to part respiratory diverticulum. An expansion VR has been well described, whereas fate diverticulum is still obscure, although its pharyngeal opening corresponds glottis. We observed sagittal sections 10 embryos (five specimens at 5–6 weeks and another five 7–8 weeks) eight fetuses 25–30 weeks. At 5–6 weeks, a lumen appeared, subsequently, opened into epithelial lamina. Because this discrete separation, it seemed unlikely that pouches contributed epithelium. 6–7 weeks, exhibited high boot-shaped with canalization diverticular level cricoid cartilage. Thus, in midline area between bilateral arytenoid cartilages, double lumina were evident, separated by thick 25–30 weeks, inferior had become enlarged because destruction lamina along corniculate cartilages. In contrast, candidates for initial remained as slits anterosuperior side transverse muscle. Therefore, final lateral walls originate from canalization, contrast posterior wall derived wall.