Introduction to the Reproductive System

Definitions

• Gamete: haploid cell

• Male gamete: spermatozoa

• Female gamete: oocyte or ovum

Anatomy of the pelvic cavity

• Lies within the bony pelvis, between the pelvic inlet and the pelvic outlet

• Continuous with abdominal cavity

• Pelvic floor: internal wall of skeletal muscle that separates the pelvic cavity and the perineum

• Perineum: inferior to pelvic floor, situated between the proximal parts of lower limbs

• Pelvic roof: formed by parietal peritoneum (lining of abdominal cavity)

• Peritoneal cavity: space between visceral and parietal cavity

Rectouterine pouch (of Douglas)

• Double folding of the peritoneum between the rectum and the posterior wall of the uterus

• Most inferior part of the peritoneal cavity in an upright female patient

Utero-vesicle pouch

• Double folding of peritoneum between the anterior surface of the uterus and the bladder

Female reproductive system

Dissected female pelvis

Surface anatomy of the female perineum

Female reproductive organs

• Ovaries

• Accessory reproductive organs - uterine tubes, uterus, vagina

Layers of the uterus wall

• Perimetrium

• Myometrium

• Endometrium

Ovulation + menstruation

1. Ova released from ovaries into peritoneal cavity

2. Ovum gathered by fimbriae into infundibulum of uterine tube

3. Ovum moved along uterine tube by cilia until it reaches the uterus

4. During menstruation, an unfertilized ovum is expelled by contractions of the myometrium

Early pregnancy

• Fertilization: usually occurs in the ampulla

• Implantation: usually occurs in the body of the uterus

• Ectopic pregnancy: fertilized ovum implants outside of the uterine cavity

Male reproductive system

Surface anatomy of the male perineum

Male reproductive organs

• Testes

• Accessory reproductive organs - vas deferens, prostate gland, penis
• 3 cylinders of erectile tissue become filled with blood at arterial pressure during erection

Retrovesical pouch

• Double folding of peritoneum located between the rectum and the bladder 

Development of the testes

• During development the testis originate on the posterior wall of the abdominal cavity

• By birth they have descended into the scrotum through the anterior abdominal wall

Production of spermatozoa

• Produced in the seminiferous tubules

• Sperm pass to rete testis, then into head of epididymis

• Epididymis becomes vas deferens

• Spermatic cord contains:
• Vas deferens
• Testicular artery
• Pampiniform plexus of veins

Ejaculation

 

• Sperm pass from the testes via the vas deferens (part of the spermatic cord)

• Each spermatic cord passes through the anterior abdominal wall to reach the pelvic cavity

• Each vas deferens connects with the duct from a seminal gland - ejaculatory duct

• Right and left ejaculatory ducts join together within the prostate and drain into urethra

• Urethra opens at the external urethral meatus of the penis

Torsion of the testis

• Twisting of the spermatic cord

• Disrupts blood supply - severe pain, danger of necrosis

Sterilisation

Females

• Tubal litigation

• Uterine tubes clipped, cut or cauterized

Males

• Vasectomy

• Vas deferens transected and lumen sutured shut