Smith T D, Siegel M I, Mooney M P, Burdi A R, Burrows A M, Todhunter J S
School of Physical Therapy, Slippery Rock University, Pennsylvania 16057-1326, USA.
Anat Rec. 1997 Jul;248(3):447-55. doi: 10.1002/(SICI)1097-0185(199707)248:3<447::AID-AR18>3.0.CO;2-P.
Vomeronasal organs (VNOs) are paired epithelial structures located adjacent to the nasal septum that form in the late first trimester of human fetal development. Although VNOs have long been known to exist in fetal and adult humans, some studies continue to suggest that these structures may be degenerative or functionless. Little is known of the growth of the VNO.
The present study examined length and volume changes of the human VNO in 26 "normal" (10 female, 16 male) histologically prepared fetuses from the University of Pittsburgh and the University of Michigan across three trimesters (8-30 weeks postmenstrual age). A computer reconstruction technique was used to quantify lengths and volumes of right and left VNOs, and regression equations were generated to assess growth rates.
A linear increase in VNO length and a logarithmic increase in VNO volume with increasing postmenstrual age was found. Volume increase was noted for both the vomeronasal epithelium and the lumen of the VNO. A comparison with most estimates of adult human VNO length suggested that further prenatal or postnatal size increase occurs. The growth curves also suggested a more rapid growth in VNO length and volume for females than for males.
The present study demonstrates that the fetal human VNO commences volumetric increase in the early second trimester but does not achieve maximum size during fetal development. Further investigation is needed to determine whether the human VNO is sexually dimorphic in size.
犁鼻器（VNOs）是成对的上皮结构，位于鼻中隔附近，在人类胎儿发育的孕早期晚期形成。尽管长期以来已知胎儿和成年人体内存在犁鼻器，但一些研究仍表明这些结构可能会退化或无功能。关于犁鼻器的生长情况知之甚少。
本研究检查了来自匹兹堡大学和密歇根大学的26例“正常”（10例女性，16例男性）经组织学处理的胎儿在三个孕期（月经龄8 - 30周）的人类犁鼻器的长度和体积变化。使用计算机重建技术量化左右犁鼻器的长度和体积，并生成回归方程以评估生长速率。
发现随着月经龄增加，犁鼻器长度呈线性增加，体积呈对数增加。犁鼻器上皮和犁鼻器腔的体积均有增加。与大多数对成年人类犁鼻器长度的估计值相比，表明产前或产后还有进一步的尺寸增加。生长曲线还表明，女性犁鼻器的长度和体积增长比男性更快。
本研究表明，人类胎儿犁鼻器在孕中期早期开始体积增加，但在胎儿发育期间未达到最大尺寸。需要进一步研究以确定人类犁鼻器在大小上是否存在性别差异。
