The present review aims to present a perspectiveon a relatively unknown part of the mammalian internal genitalia: their cranial suspensory apparatus. This apparatus shows wide divergence of development when examined during the fetal period or during adulthood, in males or females, or in individuals across a variety of species. In rats and other mamalian species the apparatus undergoes a distinct patern of sexually dimorphic development and fetal testicular androgens are proposed to play a key role in this process. Extensive development of this suspensory apparatus in females is argued to be a part of the anatomical adaptations of the genital apparatus to support the internal genitalia throughout pregnancy, including the relatively enormous growth towards the time of parturition. Minor development of this apparatus in males is judged to be a part of the anatomical requirements allowing developing testes to become displaced from the dorsal abdominal wall during the first stage of testicular descent. Extensive development of this suspensory apparatus in males generally seems to hinder testicular descent. Accordingly, the apparatus is well developed in so-called testicond species which do not show testis descent as a part of their normal male genital development. Furthermore, arguments are adduced that inappropriate and extensive development in species with testis descent may be a key aetiological factor in the disturbance of this process. Diagnosis and treatment of human cryptorchidism might profit from including an analysis of the development and function of (remnants of) the cranial testicular and epididymal suspensory apparatus.

中文翻译：

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跨物种视角的哺乳动物性腺的颅悬韧带的发育，结构和功能；它们在影响睾丸后裔下降中的可能作用。

本文旨在就哺乳动物内部生殖器的一个相对未知的部分：他们的颅骨悬吊装置提出一个观点。在胎儿期或成年期检查时，无论是雄性还是雌性，还是各种物种的个体，这种仪器都显示出很大的发育差异。在大鼠和其他哺乳动物中，该装置经历了明显的性二态发育模式，并且胎儿睾丸雄激素被认为在该过程中起关键作用。据认为，这种悬吊器具在女性中的广泛发展是整个生殖器解剖结构适应的一部分，以在整个怀孕期间支持内部生殖器，包括在分娩时相对较大的增长。这种设备在男性中的较小发育被认为是解剖学要求的一部分，允许在睾丸下降的第一阶段使发育中的睾丸从背腹壁移位。这种悬吊器具在男性中的广泛发展似乎通常会阻碍睾丸下降。因此，该设备在所谓的睾丸物种中得到了很好的发展，这些物种没有显示出睾丸下降作为其正常男性生殖器发育的一部分。此外，有人认为，睾丸后裔物种的不适当和广泛的发展可能是造成这一过程紊乱的关键病因。