Female reproductive organs

Uterus and cervix

Embryology

Anatomy

  • Location: pelvis, partially covered by peritoneum
  • Parts (cranial to caudal)
    • Body
    • Isthmus: a constriction between the body and the cervix
    • Cervix: lowermost cylindrical part of the uterus that lies between the internal and external orifice of the uterus
      • Portio supravaginalis: the part of the cervix that lies above the vagina
      • Portio vaginalis: the part of the cervix that protrudes into the fundus of the vagina
  • Position: usually anteverted by 90°, anteflexed by 120°, and slightly dextrorotated
    • Variants (e.g., retroflexion) occur in 10% of women and may impair conception
  • Neighboring structures
  • Functions: accepts the fertilized ovum; site of implantation and growth of the fetus during pregnancy
  • Blood supply
    • Arterial supply
    • Venous drainage: occurs via the venous plexus in the uterine wall (uterine plexus) and in the uterine vein.
  • Lymphatic drainage: external iliac nodes
  • Nerve supply
  • Ligaments: flexible attachment of the uterus in the pelvis (pelvic floor muscles provide additional support)
    • Excessive strain on the ligaments and pelvic floor muscles → uterine prolapse; risk factors include multiple vaginal births, complicated births
Uterine ligaments Description Location Structures within the ligament

Broad ligament

  • Peritoneal fold that forms the mesosalpinx, mesometrium, mesovarium
  • Intraperitoneal location
  • Connects the lateral uterus, fallopian tubes, and ovaries with the lateral pelvic wall
Round ligament of uterus
  • Embryonic derivate of the gubernaculum
  • Responsible for the anteversion-anteflexion position of the uterus

Cardinal ligament

(Mackenrodt ligament)

  • Connects the cervix with the lateral pelvic wall

Microscopic anatomy

Uterus

Cervix and Cervical Os

Ovaries

Anatomy

Ovarian ligaments Description Location Structures within the ligament
Infundibulopelvic ligament
  • Suspensory ligament of the ovaries
  • Connects the ovaries with the lateral pelvic wall
  • Ovarian artery and vein
    • During oophorectomy, these vessels must be ligated. Care must be taken not to damage the ureter, which is located directly posterior to the ligament in the retroperitoneum.
Ovarian ligament
  • Connects the medial pole of the ovaries with the uterine horn
Mesovarium
  • Between the ovaries
  • Ovaries

Microscopic anatomy

Ovarian follicles

Oogenesis

  • Definition: development of an immature oocyte into a mature egg cell.

Cell

Timing Process Chromosome count

Oogonium

  • Begins at 4th week of gestation
  • Complete in third trimester
Primary oocyte
  • Complete by approx. 4 weeks before birth

1. Latent phase (dictyate)

Secondary oocyte
  • Ootidogenesis
  • Folliculogenesis: FSH stimulates the maturation of ovarian follicle (up until ovulation)
    • Multiple primordial follicles develop during one menstrual cycle: primary follicle → secondary follicle → tertiary follicle
      • Primary follicle: oocyte surrounded by granulosa, zona pellucida, and theca cells
      • Secondary follicle: antrum develops
    • Only one tertiary follicle matures into the dominant Graafian follicle (completes first meiotic division) then ovulation takes place
    • The remaining tertiary follicle degenerate (follicle atresia)
2. Latent phase
Ootid
  • Ootidogenesis: meiosis II complete
  • Becomes a mature ovum

The primary oocyte is arrested in the prophase I of meiosis I until ovulation. The secondary oocyte is arrested in the metaphase II of meiosis II until fertilization.

Primary oocytes are formed prior to birth and represent a woman's ovarian reserve.

Vagina and vulva

Embryology

Vagina

Anatomy

  • Location: pelvis, extraperitoneal; suspended by the paracolpium
  • Parts
    • Vaginal fornix: surrounds the cervix
    • Vaginal wall
    • Vaginal ostium or orifice
  • Neighboring structures
  • Blood supply
    • Arterial blood supply: vaginal and uterine branches from the internal iliac artery
    • Venous drainage: uterine and vaginal venous plexus to the uterine veins
  • Innervation: pudendal nerve
  • Lymphatic drainage

Microscopic anatomy

  • Transverse folds
  • Three layers:
    • Mucosal: nonkeratinized stratified squamous epithelium devoid of glands
    • Lamina propria
    • Muscular
    • Adventitial

Function

  • Barrier against ascending infections: due to its acidic pH 4–4.5
  • Lubrication upon sexual arousal
  • Sexual stimulation
  • Passageway for menstrual blood
  • Conduit for childbirth

Vulva

Anatomy

  • Description: external female genitalia
  • Parts
    • Labia majora: lateral border of the vulva; merge anteriorly to form the mons pubis; surround and cover the vaginal ostium and the labia minora; skin contains sebaceous and sweat glands and pubic hair
    • Labia minora: surround the vaginal vestibule; skin is hairless and devoid of sweat glands but contains sebaceous glands
    • Vaginal vestibule: contains
      • Greater vestibular glands (Bartholin gland) merge into the vaginal vestibule
        • Obstruction of the glands → accumulation of mucous fluid → Bartholin cyst
        • Infection of the Bartholin cyst → Bartholin abscess (associated with gonococcal infection)
      • Skene's glands (lesser vestibular glands): secret an alkaline fluid for lubrication
      • Periurethral glands
      • Urethra
    • Clitoris: anterior to the labia minora; erogenous zone composed of corpora cavernosa
    • Hymen: membrane that partially covers or surrounds the vaginal opening
  • Blood supply
    • Arterial supply: internal pudendal artery and external iliac artery
    • Venous drainage: labial and clitoral branches into the internal pudendal vein
  • Innervation
    • Pudendal nerve
    • Anterior labial nerves of the ilioinguinal nerve
    • Genital branches of the genitofemoral nerve
  • Lymphatic drainage: superficial inguinal lymph nodes, which then drain into the external iliac lymph nodes

Hymen atresia causes complete occlusion of the vagina, which obstructs blood flow at menarche, causing primary amenorrhea and hematocolpos.

Estrogen stimulates proliferation and keratinization of the vulvar epithelium. Menopause with decreased estrogen levels results in vulvar atrophy.

Clinical significance

Endometrial conditions

Cervical conditions

Ovarian conditions

Vaginal and vulvar conditions

  • Standring S. Gray's Anatomy: The Anatomical Basis of Clinical Practice. Elsevier Health Sciences; 2015.
  • Gilman S. Neurobiology of Disease. Academic Press; 2007.
  • Ogeng'o J. Chapter 36: Female Reproductive System and the Contents of the Female Pelvis. http://www.oganatomy.org/projanat/gross/36/six.htm. Updated January 1, 2018. Accessed November 24, 2018.
  • Miranda AM. Vaginal Anatomy. In: Gest TR. Vaginal Anatomy. New York, NY: WebMD. https://emedicine.medscape.com/article/1949237. Updated September 24, 2018. Accessed November 24, 2018.
last updated 11/24/2018
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