Reproductive Organs

Anatomy of Male and Female Internal Genitalia

• Under hot conditions, the scrotal skin becomes flaccid and loose, and the testes hang low to increase skin surface for cooling, performed by dartos and cremaster muscles.
• The testes are covered by visceral and parietal layers of the thin serous membrane, the tunica vaginalis, and contain seminiferous tubules where sperm are produced.
• The testes receive arterial blood from the testicular arteries branching from the abdominal aorta around L1 vertebral level, and the testicular veins drain to the left renal vein and the inferior vena cava.
• The vas deferens transports sperm from the epididymis to the ejaculatory duct of the urethra and joins the duct of the seminal vesicle to form the ejaculatory duct.
• The prostate gland, situated inferior to the neck of the bladder, has lobes including anterior, (infero)posterior, right and left lateral, and middle lobes.
• The blood supply to male internal genital organs includes the deferential artery, prostatic venous plexus, and inferior vesical artery, with lymph draining to the lymph nodes around the internal and common iliac arteries.
• The female internal genitalia include the vagina, a musculomembranous tube with a vaginal fornix, and is related anteriorly to the urethra and bladder.
• The secretions of the seminal vesicles contribute nutrients to the liquid portion of semen and the walls contract during ejaculation.
• Bulbourethral glands, located in the deep perineal pouch, also contribute to semen and drain into the spongy portion of the urethra.
• The tumor of the prostate gland spreads through the pelvic lymphatics to the lymph nodes around the internal and common iliac arteries and the aorta.
• Carcinoma of the prostate spreads through hematogenous and lymphatic routes, showing a tendency to cause bony metastases due to connections between the prostatic venous plexus and the internal vertebral veins.
• The vaginal fornix is a recess within the superior end of the vagina, around the inferior end of the cervix, with anterior, posterior, and lateral parts.

Female Pelvic Anatomy and Support Structures

• The uterus consists of the body, isthmus, and cervix, with the cervical canal opening into the vagina at the external os and into the uterus at the internal os. Its normal position is anteflexed and anteverted.
• The uterine tubes have four parts: infundibulum, ampulla, isthmus, and uterine (intramural) part, and transport the ovum and zygote from the ovary to the uterine cavity.
• The ovaries are female gonads and are connected to the uterus by the proper ovarian ligament and the round ligament of the uterus.
• Peritoneal reflections form the rectouterine pouch, vesicouterine pouch, and the suspensory ligament of the ovary, providing support for the female pelvic organs.
• The broad ligaments consist of double folds of peritoneum that enclose the uterus, uterine tubes, and ovaries, with the mesometrium, mesosalpinx, and mesovarium visible posteriorly.
• The pelvic fascia, an inferior continuation of the transversalis fascia, stabilizes the uterus through condensations forming the pubocervical, uterosacral, and transverse cervical (cardinal) ligaments.
• The blood supply to the female internal genitalia includes the uterine artery, ovarian artery, vaginal artery, and internal pudendal artery, each supplying specific regions.
• Lymphatic drainage of the uterus and ovaries occurs via the round ligament of the uterus to the superficial inguinal nodes, while the vagina drains to the superficial inguinal nodes as well.
• The kidneys and suprarenal glands are retroperitoneal, while the peritoneum covers the superior surfaces of the pelvic viscera, making them subperitoneal.
• The pelvic viscera, except for the uterine tubes, are considered subperitoneal, as they are not derived from the gut tube and are covered by peritoneum.
• The rectouterine pouch is the most inferior point of the peritoneal cavity in females, while the vesicouterine pouch is located between the bladder and the uterus.
• The peritoneum drapes over the ovarian vessels, creating the suspensory ligament of the ovary and connecting the ovaries to the angle of the uterus.

Test your knowledge of male and female internal genitalia with this anatomy quiz. Explore the structures, functions, and blood supply of the male and female reproductive systems, as well as the support structures of the female pelvis.