Anatomy and Physiology of Children and Adolescents - M. R. Sapin 2007

Urogenital system
Reproductive system
Male reproductive organs - Internal male genitalia

The Testis is a paired reproductive gland that performs vital Functions in the male body. The Testes produce spermatozoa as well as Sex Hormones that influence The Development of Primary and secondary sex characteristics. Therefore, the testes function simultaneously as exocrine and Endocrine glands. The testes, along with their epididymides, are located outside the Abdominal cavity in a specialized pouch—the Scrotum, where they are separated from each other by a Connective Tissue septum.

The testis is ovoid in shape, firm in consistency, and its exterior is covered by a smooth, glossy tunica albuginea. The Epididymis lies adjacent to the posterior border of the testis. Septa extend inward from the tunica albuginea toward the epididymis, merging in the posterior region of the organ to form a thickening known as the Mediastinum testis. These septa divide the testis into 100–300 lobules. Each lobule contains 1–2 convoluted seminiferous tubules (Fig. 66). Each tubule measures 50–80 cm in length. Near the mediastinum, the tubules gradually straighten, transitioning into straight tubules that empty into the rete testis located within the mediastinum. The efferent ductules (15–20) emerge from the rete testis and enter the HEAD of the epididymis.

The PARTS OF THE epididymis include the head, body, and tail, from which the Ductus deferens originates. The efferent ductules of the testis that enter the epididymis continue into the convoluted ductules of the epididymis, and subsequently into the long (up to 6–8 m) duct of the epididymis. Coiling repeatedly, the duct of the epididymis continues into the ductus deferens in the region of the tail of the epididymis.

The ductus deferens runs upward posterior to the testis, where, together with Blood Vessels and nerves, it forms the Spermatic Cord, which passes through the Inguinal Canal into the pelvic cavity. Measuring 40–50 cm in length, the ductus deferens extends toward the Base of the Urinary Bladder, where it joins the excretory duct of the Seminal Vesicle.

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Fig. 65. Male Urogenital System:

1 — Kidney; 2 — renal cortex; 3 — renal pyramids; 4 — renal pelvis; 5 — Ureter; 6 — apex of urinary bladder; 7 — median umbilical ligament; 8 — body of urinary bladder; 9 — body of Penis; 10 — dorsum of penis; 11 — glans penis; 12 — testicular lobules; 13 — testis; 14 — epididymis; 15 — ductus deferens; 16 — ROOT of penis; 17 — Bulbourethral gland; 18 — membranous part of Urethra; 19 — Prostate Gland; 20 — seminal vesicle; 21 — ampulla of ductus deferens; 22 — base of urinary bladder; 23 — renal hilum; 24 — renal artery; 25 — renal vein

The seminal vesicle is a paired organ located posterior and lateral to the base of the urinary bladder.

The seminal vesicle is approximately 5 cm long and consists of a coiled tubule that measures 10–12 cm in length when uncoiled. The excretory duct of the seminal vesicle joins the ductus deferens to form a short ejaculatory duct. This duct opens into the initial prostatic part of the male urethra adjacent to the seminal colliculus.

Spermatozoa produced in the testis undergo final maturation as they travel along the long spermatic ducts toward the urethra.

The secretion produced by the epithelium of the epididymal tubules, as well as by the epithelium of the Seminal Vesicles located near the urinary bladder, liquefies the semen and helps activate the spermatozoa.

The Glands of the Male Reproductive System are situated along the pathways traveled by spermatozoa (semen) from their site of formation in the testes to their expulsion from the male reproductive tract. These glands include the prostate gland and the Bulbourethral Glands.

The prostate gland is an unpaired fibromuscular organ whose shape and size are comparable to a chestnut. It is located directly beneath the urinary bladder. The initial (prostatic) part of the urethra and both ejaculatory ducts pass through the prostate gland. The prostate consists of 30–60 tubuloalveolar prostatic glands. The ducts of these glands open into the prostatic urethra. The contraction of the Muscle bundles—well-developed in adult males and surrounding the prostatic glands—facilitates the discharge (expulsion) of its secretion during ejaculation.

Fig. 66. Structure OF THE testis and its epididymis:

1 — ductus deferens; 2 — efferent ductules of testis; 3 — duct of epididymis; 4 — mediastinum testis; 5 — rete testis; 6 — straight seminiferous tubules; 7 — septum between testicular lobules; 8 — convoluted seminiferous tubules; 9 — interconnections between seminiferous tubules of different lobules; 10 — tunica albuginea; 11 — lobule of epididymis

The bulbourethral gland is a pea-sized paired organ located within the urogenital Diaphragm, posterior to the membranous part of the urethra. The secretion of these glands enters the urethra and becomes a component of semen.