Female Reproductive System — First Year Anatomy

Overview

1. Ovaries

• Paired, almond-shaped organs (~3 × 1.5 × 1 cm) located on the posterior surface of the broad ligament in the lateral pelvic wall
• Attached to the broad ligament by the mesovarium, to the uterus by the ovarian (utero-ovarian) ligament, and to the pelvic sidewall by the suspensory (infundibulopelvic) ligament (which carries the ovarian vessels and lymphatics)
• Covered by germinal epithelium (simple cuboidal) overlying a dense connective tissue capsule: the tunica albuginea

1. Gametogenesis (oogenesis) — production of secondary oocytes
2. Steroidogenesis — secretion of estrogens (promote maturation of sex organs, secondary sexual characteristics) and progestogens (prepare uterus for pregnancy)

2. Ovarian Follicles (Key First-Year Concept)

3. Uterine (Fallopian) Tubes

• ~10 cm long; extend laterally from the uterine cornua
• Four parts (lateral → medial): Infundibulum → Ampulla → Isthmus → Intramural (uterine) portion

4. Uterus

• Pear-shaped, hollow muscular organ; normally anteverted and anteflexed in the pelvis
• Lies between the bladder (anterior) and rectum (posterior)

1. Endometrium (inner) — mucosa; cyclically shed during menstruation; has functional and basal layers
2. Myometrium (middle, thickest) — smooth muscle arranged in three poorly defined layers; responsible for contractions of labor
3. Perimetrium (outer) — peritoneal (serosal) covering

5. Cervix

• Narrow, fibrous distal part of uterus; visualized at the top of the vaginal canal
• Central canal = os (internal os opens into uterine cavity; external os opens into vagina)
• Ectocervix: stratified squamous epithelium
• Endocervix (cervical canal): mucus-secreting columnar epithelium
• Transformation zone: squamocolumnar junction — the clinically important site where cervical intraepithelial neoplasia (CIN) arises — Sabiston Textbook of Surgery

6. Vagina

• Fibromuscular tube extending from cervix to vestibule; lies mostly horizontal in the upright posture
• Wall layers (inside → out): stratified squamous nonkeratinized epithelium → lamina propria (collagen, elastic tissue) → muscular layer → areolar connective tissue
• No glands; lubrication comes from cervical mucus and transudate
• Blood supply: Vaginal artery (branch of internal iliac); multiple anastomoses with uterine, internal pudendal, inferior vesical, and middle rectal arteries
• Nerve supply: Lumbosacral plexus (S2–S4) → pudendal nerve; most sensory innervation is in the distal third — Sabiston Textbook of Surgery

7. External Genitalia (Vulva)

8. Pelvic Blood Supply Summary

• Common iliac artery → bifurcates at sacral promontory into external and internal iliac arteries
• Internal iliac (hypogastric) artery → anterior division → uterine artery, vaginal artery, superior/inferior vesical arteries, middle rectal artery, obturator artery, pudendal artery
• Ovarian arteries arise directly from the aorta (L1) — Sabiston Textbook of Surgery

9. Innervation

• Obturator nerve (L2–L4): medial thigh
• Femoral nerve (L2–L4): anterior thigh
• Sciatic nerve (L4–S3): posterior thigh and leg
• Pudendal nerve (S2–S4): perineum and external genitalia
• Sympathetic supply regulates uterine and vascular tone; parasympathetic (S2–S4) mediates vasodilation and secretion

Quick Memory Summary

Ovary → Uterine tube (infundibulum–ampulla–isthmus–intramural)
     → Uterus (fundus–body–isthmus–cervix) 
     → Vagina → Vestibule (vulva)

Uterine wall: Endometrium / Myometrium / Perimetrium
Ovarian follicle stages: Primordial → Primary → Secondary → Graafian
Fertilization site: Ampulla of uterine tube
Implantation site: Posterior wall of uterine body (endometrium)
Main support ligament: Cardinal ligament (prevents prolapse)