How does ejaculation occur in dogs? - briefly
Ejaculation in dogs occurs through the process of penile erection and intromission, followed by the release of semen from the bulbourethral glands and prostate, which mixes with sperm from the testicles before being expelled through the penis. This reflex action is typically triggered by the stimulation of the penis during mating.
How does ejaculation occur in dogs? - in detail
Ejaculation in dogs is a complex physiological process that involves several stages and is governed by both hormonal and neurological signals. The process begins with sexual arousal, which triggers the release of various hormones, including testosterone and luteinizing hormone (LH). These hormones stimulate the production of sperm in the testes and the secretion of seminal fluid by the prostate and bulbourethral glands.
During copulation, the penis becomes erect due to increased blood flow facilitated by the relaxation of smooth muscles in the penile tissue. This is mediated by the release of nitric oxide, which in turn stimulates the production of cyclic guanosine monophosphate (cGMP). The erect penis allows for successful penetration and intromission into the female's vagina.
As the male dog thrusts, the pelvic muscles contract rhythmically, propelling the sperm-containing semen through the urethra. This process is coordinated by the autonomic nervous system, specifically the sympathetic nerves, which trigger contractions of the muscular walls of the epididymis, vas deferens, and urethra. The ejaculate consists of spermatozoa from the testes and seminal fluid from the accessory glands, providing a medium that supports and nourishes the sperm during their journey to fertilize the ova.
After ejaculation, the male dog typically exhibits a refractory period known as the "tie," where the bulbus glandis of his penis swells and becomes locked within the female's vagina. This period can last from 5 to 45 minutes, ensuring that the semen has ample time to be deposited deep into the female's reproductive tract, thereby increasing the chances of successful fertilization.
Throughout this process, the neuroendocrine system plays a critical role in regulating hormone levels and coordinating the various stages of ejaculation. The interplay between these systems ensures the efficient and effective transfer of genetic material from the male to the female during mating.