The structure composed of the upper and lower muscles fascia of the urogenital diaphragm, as well as the deep transverse muscle of the perineum between them, and the urethral sphincter is called the urogenital diaphragm. It closes the urogenital triangle, with the urethral opening in men and the urethra and vagina in women. It elevates the pelvic floor, helping to support the pelvic visceral organs.

Anatomical characteristics of the urogenital diaphragm

The cross-section of the cadaveric specimen can be seen to have a three-layer structure of the urogenital diaphragm. The upper and lower sides are the superior and inferior urogenital diaphragm fascia, respectively, and the middle is the deep transverse muscle of the perineum. The deep transverse muscle of the perineum has not filled the deep perineal space. The superior urogenital diaphragm fascia is adjacent to the tip of the prostate in men, and the perineal fascia is adjacent to the cavernous body of the penis; the female urogenital diaphragm is shorter than that of men, and the urethra and vagina surround the urogenital diaphragm. In men, from the tip of the prostate to the cavernous body of the penis, it can be seen that the muscle bundles of the urethral sphincter cross the urogenital diaphragm, but in the female specimen slices, this structure is weaker, and only a small amount of muscle bundles are seen in the coronal slices.

The male sperm produced by the male testicles are first stored in the epididymal cyst, and when men ejaculate, they are excreted outside the body through the ejaculatory duct, the vas deferens, and the urethral orifice. The fluids secreted by the seminal vesicle, prostate, and bulbourethral glands participate in the composition of semen, providing nutrients for male sperm and enhancing the attractiveness of male sperm. External genitalia

Male internal urinary system illustration photo

It includes the male reproductive organs and the scrotum. The male reproductive organ is the sexual organ of men, through which the urethra passes, with the functions of urination and male ejaculation; the scrotum, in addition to protecting the male testicles and the spermatic cord, also maintains a lower temperature inside the scrotum, which is an essential standard for the normal growth and development of male sperm. Male internal urinary system

Male internal urinary system male testicles

The male testicles are the location of the male prostate, with one above and one below, in an oval shape, suspended and trained in the scrotum by the spermatic cord, about 4-5 cm long, 3-4 cm thick, and weighing about 15g each. It is the human organ that produces male germ cells (i.e., male sperm) and is also the key endocrine gland that produces androgens.

The internal structure of the male testicles: The surface of the male testicles has a thick dense connective tissue membrane called the tunica albuginea. The inner side of the tunica albuginea is loose connective tissue, which contains a rich variety of blood vessels, known as the tunica vasculosa. The tunica albuginea of the male testicles thickens between the bones and sinks deeply into the male testicles, forming the male testicular septum. The septum extends radially into the substance of the male testicles, dividing them into multiple lobes. Each lobe contains 1-3 coiled seminiferous tubules, which converge at the top of the lobe to form a short and straight straight tubule, entering the septum. Within the septum, these small tubes interlock to form a network, producing the male rete testis. From the male rete testis, 12-13 coiled tubes called the male vasa efferentia emerge, which pass through the tunica albuginea into the epididymal cyst head. The interstitial cells of the seminiferous tubules can metabolize androgens, promoting the growth and development of the male reproductive organs and male secondary sexual characteristics, and maintaining them. The squamous epithelial cells of the seminiferous tubules are responsible for the production of sperm. The seminiferous tubules merge to form straight tubules, which are the conduit system for the transport of male sperm. Finally, they converge to form a single tube that enters the epididymal cyst head, and are excreted outside the body through the ejaculatory duct.