Morphological characteristics of the epididymal region of the domestic pigeon (Columba livia, L.)

Abstract

The epididymal region of the domestic pigeon comprises the main part of the rete testis, the efferent ductules of the testis and the ductus epididymidis. The channels of the rete testis albuginic segment are continuous with the extratesticular rete testis segment. This part is sequent to the proximal and distal efferent ductules, and at last the epididymal duct is formed in continuity with the distal efferent ductules. The epithelium that lines this tubular system is simple cuboidal in rete testis complex and pseudostratified columnar in the other parts of the spermatic ducts, with ciliated and non-ciliated cells mainly observed in the efferent ductules. Based on the ultrastructural features of the epithelial cell types of the epididymal region of pigeon, perhaps resorption process of seminal fluid is the main function of the epithelial cells. Comparatively, other cytophysiological roles are also proposed such as: adsorptive endocitose, an apocrine secretory process in dark non-ciliated cells and active ciliogenesis in ciliated cells.