[Morphology and development of the bovine testicular artery during fetal and neonatal periods].

Abstract

The studies of the morphology and development of the testicular artery in cattle have been carried out on 95 preparations--85 male fetuses from the 8-40th week of pregnancy and 10 neonates at the age of 1 to 14 days of life. The age of the fetuses has been determined by Kantorova method supplemented with the methods of other authors. The observations have been made using rubber latex introduced into the examined arteries by means of the automatic device of our own design. On the basis of the performed examinations the following generalizations, conclusions and nomenclature suggestions can be made: Testicular arteries in cattle, in most cases, develop from the last pair of mesonephric lumbar arteries (aa. mesonephridicae lumbales) in embryo and through a number of evolutionary changes in the course of development transform from the simple form characteristic of the youngest fetuses (8-10 weeks) into the form approximate in the new born animals to the final form typical of the adult cattle. The examined arteries were formed in the process of quantitative and qualitative transformations which occurred, both, in the main trunk of the testicular artery, and its permanent and temporary secondary branches. Transformations of this kind are typical of developmental changes which either become more prominent or disappear with age. The formation of the characteristic of sex and species shape of the testicular artery results from these transformations and is determined by the physiological and hemodynamic needs of the testicle and epididymis, which are supplied by that artery only. Taking into account the shape and topography of the testicular artery it is possible to distinguish the following three sections in its finally formed main trunk: 1) straight part (pars recta), 2) convoluted part (pars convoluta) and 3) marginal part (pars marginalis). Temporary branches such as uretral branch (ramus uretericus) and renal capsule branch (ramus capsularis renis) are derivatives of the straight part of the studied artery. From the convoluted part of the testicular artery there arise as permanent vessels--branch of the ductus deferens (ramus ductus deferentis) and epididymal branch (ramus epididymalis) and, additionally, as a temporary vessel--I order accessory testicular branch (ramus testicularis I ordinis accessorius). The marginal part of the testicular artery divides into two final branches of the examined vessel. i.e., medial and lateral testicular branches of I order. Further order derivatives of them enter parenchyma of the testicle and form within that organ its own blood circulation. (ABSTRACT TRUNCATED AT 400 WORDS)