Структурни и функционални механизми на пенилната ерекција

Erectile function is a highly coordinated biological process that integrates anatomical, neurological, vascular, endocrine, and psychological mechanisms into a single functional response. Understanding these mechanisms is essential not only for clinical medicine in urology and andrology, but also for interdisciplinary fields such as cardiology, endocrinology, and neurology. Anatomically, the penis is composed of two corpora cavernosa and one corpus spongiosum, surrounded by a highly organized fibroelastic structure – the tunica albuginea.
The microarchitecture of the cavernous tissue, composed of sinusoidal spaces lined by endothelium and surrounded by smooth muscle cells, allows for dynamic regulation of blood flow and intracavernous pressure. Arterial vascularization originates from the a. pudenda interna, via the a. profunda penis and a. dorsalis penis, while venous outflow is regulated through a subtle mechanism of venous occlusion, followed by compression of the subtunical venules. The integrity of these structures is a prerequisite for achieving and maintaining a rigid erection.
Physiologically, an erection is the result of a complex neurovascular cascade. Central structures, including the hypothalamus and limbic system, play a key role in psychogenic stimulation, while reflexogenic erection is mediated through sacral segments S2–S4. Parasympathetic activation leads to the release of nitric oxide (NO) from neuronal and endothelial isoforms of NO synthetase. Nitric oxide activates soluble guanylate cyclase, resulting in increased production of cyclic guanosine monophosphate (cGMP) and relaxation of smooth muscle in the corpus cavernosum. This process allows for increased arterial inflow, expansion of sinusoidal spaces, and mechanical compression of venous outflow, thereby creating functional venous occlusion and increased intracavernous pressure. Detumescence is mediated through sympathetic activation and increased phosphodiesterase type 5 (PDE5) activity, which leads to the breakdown of cGMP and smooth muscle contraction. Hormonal status, particularly testosterone levels, plays a key role in maintaining the structural integrity of the cavernous tissue, the regulation of NO synthetase, and sexual desire. Dehydroepiandrosterone plays a small but important role in activating NO synthetase, which contributes to the hormonal mechanism of erection.
Modern research positions erectile dysfunction as a marker of systemic endothelial dysfunction and cardiovascular risk, further emphasizing the need for an integrative approach to diagnostics and treatment.