Initial stage of fetal development of the pharyngotympanic tube cartilage with special reference to muscle attachments to the tube

• 발행기관: 대한해부학회
• 저자명: Yukio Katori Jose Francisco Rodrí guez-Vá zquez Samuel Verdugo-Ló pez Gen Murakami Tetsuaki Kawase Toshimitsu Kobayashi
• 간행물 정보: 『Anatomy and Cell Biology』Vol.45(3), 185~192쪽, 전체 8쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2012.09.30

영문 초록

Fetal development of the cartilage of the pharyngotympanic tube (PTT) is characterized by its late start. We examined semiserial histological sections of 20 human fetuses at 14-18 weeks of gestation. As controls, we also observed sections of 5 large fetuses at around 30 weeks. At and around 14 weeks, the tubal cartilage first appeared in the posterior side of the pharyngeal opening of the PTT. The levator veli palatini muscle used a mucosal fold containing the initial cartilage for its downward path to the palate. Moreover, the cartilage is a limited hard attachment for the muscle. Therefore, the PTT and its cartilage seemed to play a critical role in early development of levator veli muscle. In contrast, the cartilage developed so that it extended laterally, along a fascia-like structure that connected with the tensor tympani muscle. This muscle appeared to exert mechanical stress on the initial cartilage. The internal carotid artery was exposed to a loose tissue facing the tubal cartilage. In large fetuses, this loose tissue was occupied by an inferior extension of the temporal bone to cover the artery. This later-developing anterior wall of the carotid canal provided the final bony origin of the levator veli palatini muscle. The tubal cartilage seemed to determine the anterior and inferior margins of the canal. Consequently, the tubal cartilage development seemed to be accelerated by a surrounding muscle, and conversely, the cartilage was likely to determine the other muscular and bony structures.

목차

Abstract

Introduction

Materials and Methods

Results

Discussion

Acknowledgements

References

키워드

Pharyngotympanic tube cartilage Levator veli palatini muscle Internal carotid artery Tensor tympani muscle Human fetuses