Male and Female Reproductive Systems: Anatomy and Function

Posted on Jan 13, 2025 in Biology

Female Reproductive System

Ovaries

  • Structure: Peritoneum and tunica albuginea; ovarian cortex, medulla, follicles.
  • Features: Produce and release eggs.
  • Production:
    • Estrogens (Graafian Follicle)
    • Progesterone (Corpus luteum)
  • Ovulation: Approximately 14 days after the Graafian follicle migrates to the surface, it opens and releases the egg into the abdominal cavity. The egg is actively taken up by the tube that carries it slowly into the uterus.
  • The egg is either fertilized and implanted in the uterine lining or discharged into the environment with menstruation.
  • If the egg is fertilized, the corpus luteum persists throughout pregnancy; if not, it grows until the next cycle and is then replaced by fibrous tissue.

Vagina

  • Distensible conduit 10 cm in length.
  • Location: In the pelvis, between the urethra and rectum.
  • Relations:
    • Top: Cervix
    • Below: Hymen
    • Front: Bladder, urethra
    • Behind: Rectum
  • The cervix is projected on the inside, leaving the pouch of Douglas.
  • Structure:
    • Mucosal folds
    • Acid secretion
    • Muscular
  • Function:
    • Allows intercourse (sperm entry)
    • Channel for delivery

Vulva

  • Purpose: To allow the developed fetus outside.
  • Components: Mons, labia majora, labia minora, clitoris, hymen, perineum.

Male Reproductive System

Internal Organs

  • Essential Organs: Testes (produce sperm)
  • Accessory Organs: Conduits that carry sperm from the testicles to the outside.
  • Support Sexual Glands: Seminal vesicles, Cowper’s glands, and prostate.

External Organs

  • Penis

Testicles

  • Located in the scrotum, suspended outside the body and behind the penis.
  • Structure:
    • Surrounded by tunica albuginea, giving septa separating lobules.
    • Lobules with seminiferous tubules—long, wound structures that develop semen on the walls and release it into the lumen.
    • Tubules that converge in the rete testis, in the upper pole, are united to form the epididymis.
    • Along with septa, Leydig cells (produce testosterone).
  • Embryonic Development: The testes originate in the abdominal cavity and migrate through the inguinal canal into the scrotum. If at birth they are not in the scrotum, it is called cryptorchidism.
  • Features:
    • Produce sperm
    • Produce hormones (testosterone)

Reproductive Tract

  • The sperm formed in the seminiferous tubule passes successively through:
  • Epididymis: Comma-shaped structure at the top and back of the testicles.
  • Parts: Head, body, and tail.
  • Function: Here, the sperm matures and learns to swim.
  • Vas Deferens:
    • Route: Begins in the epididymis, passes through the inguinal canal in the spermatic cord (with the testicular artery and venous plexus pampiniform), and ends by joining the ejaculatory duct.
    • Function: Allows the sperm to leave the epididymis and scrotum and travel up to the abdominal cavity.
  • Ejaculatory Duct: The union of the vas deferens with the seminal vesicle; it passes through the prostate and empties sperm into the first part of the urethra.
  • Urethra: Finally, it passes through the penis and opens to the outside.

Accessory Sex Glands

  • Seminal Vesicles: They are located on the prostate and behind the bladder.
  • Parts: Fundus, body, and neck.
  • Conduits:
    • Receives the vas deferens.
    • The ejaculatory duct exits from it.
  • Functions: They provide 50-70% of the fluid expelled during ejaculation. It contains, especially, fructose, which is a source of energy for sperm.
  • Cowper’s Glands:
    • Pea-sized.
    • Located next to the transverse perineal muscle.
    • They flow into the dilated posterior urethra.
    • They wet the urethra and glans with an alkaline liquid that protects the vitality of the sperm.
  • Prostate: Located in the pelvis, under the bladder, and surrounding the urethra.
  • Relations:
    • Top: Urinary bladder and seminal vesicles
    • Front: Symphysis pubis
    • Behind: Rectum
    • Within: Urethra
  • Structure: Composed of glandular tissue and fibromuscular stroma.
  • Parts: 5 lobes (anterior, middle, posterior, left, right).
  • Function: Produces a clear, milky, alkaline fluid that precedes the semen and protects the vitality of the sperm.