Introduction to the Reproductive System

• Humans are typically either male or female, however ambiguous sexual characteristics can occur:

  • congenital clinical conditions of genetic or hormonal origin
  • gender dysphoria or transgender - diagnosis of individuals who feel discontent with their biologically assigned sex or gender, as male or female.
• Male primary sexual characteristics (formed during prenatal development):

  • testes
  • male genital tract
  • external genitalia
• Male secondary sexual characteristics arise during puberty and influenced by hormonal secretion initiated by the pituitary gland:

  • enlargement of genital organs
  • appearance of pubic and axillary hair
  • extensive growth of the skeleton, skeletal muscles, facial and body hair
  • narrow pelvis with broad shoulders
  • large larynx with associated deepening of the voice
• Male internal genital organs

  • testes
  • epididymis
  • vas deferens
  • seminal vesicles
  • prostate
  • bulbourethral glands
• Male external genital organs

  • penis
  • scrotum
• Female primary sexual characteristics formed during prenatal development

  • ovaries
  • female genital tract
  • external genitalia
• Female secondary sexual characteristics

  • enlargement of the genital organs
  • appearance of pubic and axillary hair
  • onset of menstruation
  • growth of mammary glands with formation of breast
  • preferential deposition of subcutaneous fat with rounded body form
• Compared to males, females have typically relatively wide pelvis with more capacious internal dimensions
• Female internal genital organs

  • ovaries
  • uterine tubes
  • uterus
  • vagina
• Female external genital organs

  • clitoris
  • vulva
  • labia
• Ductal system

  • epididymis
  • vas deferens
  • ejaculatory ducts
  • penis and urethra
• Spermatic cord

  • vas deferens
  • testicular artery and vein
  • autonomic nerves
  • lymphatic vessels
  • cremaster muscle
• The testicular artery and vein are part of the pampiniform plexus
• Male accessory sex glands (contribute to semen)

  • seminal vesicles or glands
  • prostate
  • bulbourethral (Cowper's) glands
• The prostate in males is homologous to the paraurethral glands in females.
• The bulbourethral glands in males are homologous to the vestibular glands in females
• The scrotum supports the testes
• Ovaries (female gonads) produce gametes (oocytes) and secrete hormones
• Uterine (fallopian) tubes or oviducts serve as the conduit for the transport of the sperm and oocytes for fertilisation
• Uterus (womb) serves as the pathway for the transport of sperm and site for implantation of fertilized ovum.
• Peritoneal folds and ligaments support the ovaries, uterine tube and uterus.
• Vagina serves as receptacle for penis during sexual intercourse, outlet for menstrual flow, and passageway for childbirth.
• Vulva or pudendum (female external genitalia) made up of:

  • mons pubis
  • labia majora
  • labia minora
  • clitoris
  • vestibule
• The vascular supply of the male and female reproductive systems are mainly derived from branches of the abdominal aorta and internal iliac arteries.
• Uterine artery supplies the uterus, ligaments of uterus, medial parts of uterine tube, ovary and superior part of vagina
• Vaginal branch of the uterine artery supplies the lower vagina and vestibular bulb.
• Inferior vesical artery supplies prostate, seminal glands and occasionally artery to ductus deferens
• Superior vesical artery gives artery to ductus deferens
• Middle rectal artery supplies seminal glands, testis and vagina
• Internal pudendal artery is the main artery of the perineum.
• Testicular artery supplies the testis and epididymis in males
• Ovarian artery supplies the ovary and ampullary end of the uterine tube in females.
• The ureter passes underneath the uterine artery (water under the bridge)
• Most of the lymphatic vessels of the pelvis follow the venous system.
• Parasympathetic fibres carried by pelvic splanchnic nerves from S2-S4 supply motor fibres to the uterus and vagina.
• Presynaptic sympathetic fibres (T12-L2) traverse the sympathetic trunk and are carried by the lumbar splanchnic nerves to synapse in prevertebral ganglia. Postsynaptic sympathetic fibres go through the aortic/superior and inferior hypogastric plexuses to supply the pelvic viscera.
• Visceral afferent fibres (pain from intraperitoneal structures) to the T12-L2 spinal ganglia via the sympathetic fibres.
• Visceral afferent fibres (pain from subperitoneal structures to the S2-S4 spinal ganglia via the parasympathetic fibres.
• Somatic sensation from the opening of the vagina and vulva to S2-S4 spinal ganglia via pudendal nerve of the perineum.
• Lymph nodes draining reproductive systems

  • lumbar (aortic)
  • common iliac
  • sacral
  • internal iliac
  • external iliac
  • deep inguinal
  • superficial inguinal