In mammals, the adnexal sex glands are represented by seminal vesicles, the prostate gland, urethral and bulbourethral glands, as well as glands that coagulate sperm and ampullary glands. The secret of the accessory genital glands increases the volume of the ejaculate (the share of secretions of these glands accounts for about 95% of the volume of ejaculate) promotes sperm, causes increased contraction of smooth muscle cells in the walls of the female genital tract.The purpose of this review is to analyze the morphofunctional organization of seminal vesicles and bulbourethral glands of mammalian animals and humans.The presence or absence of seminal vesicles is a species-specific feature. Among mammals, seminal vesicles are well developed in some rodents, insectivores, a number of domestic animals (cattle, pigs), and primates. These glands are absent in cloacae, marsupials, some carnivores, a number of insectivores, artiodactyls. Bulbourethral glands are well developed in rodents, bats, primates, and some ungulates.In the wall of the seminal vesicles, the mucous, muscular and outer membranes are isolated. The epithelium of the secretory parts is pseudomultitial, the interstitium is represented by loose fibrous connective tissue and a significant number of smooth muscle cells. In the wall of the bulbourethral glands, the mucosa and adventitial membrane are isolated. The secretory end sections of the bulbourethral glands are lined with a single-layer single-row epithelium, glandular cells produce a mucosal or mixed secret. The seminal vesicles and bulbourethral glands are androgen-dependent glands. In species with a seasonal pattern of reproduction, their morphofunctional characteristics undergo significant changes during the circannual rhythm of reproduction.The epithelium of seminal vesicles and bulbourethral glands is very sensitive to the action of various adverse factors (heavy metal compounds, organic xenobiotics, electromagnetic radiation, ultrasound, etc.). When exposed to various negative factors in the adnexal glands, a complex of changes occurs (edema of connective tissue and epithelium, decreased secretory activity of epithelial cells, desynchronization of the secretory cycle, desquamation of glandular epithelial cells, proliferation of interstitial connective tissue).There is a lack of information on many aspects of the characteristics of the adnexal glands of the male reproductive system, primarily on the morphology and physiology of the adnexal glands of animals in natural ecosystems, on the ultrastructural and immunohistochemical characteristics of these glands, as well as on the mechanisms of regulation of morphofunctional rearrangements of the adnexal glands during seasonal reproduction rhythms, in the conditions of adaptation to various negative influences.