Reproductive System

What are the two embryologic structures that form the internal reproductive ducts?

Müllerian (paramesonephric) ducts and Wolffian (mesonephric) ducts.

What structures develop from the Müllerian ducts?

Fallopian tubes, uterus, cervix, and upper portion of the vagina.

What structures develop from the Wolffian ducts in males?

Epididymis, vas deferens, seminal vesicles, and ejaculatory ducts.

What is the role of anti-Müllerian hormone (AMH)?

Secreted by Sertoli cells; causes regression of Müllerian ducts.

What is the role of testosterone during male sexual differentiation?

Maintains and develops Wolffian ducts.

What is the role of dihydrotestosterone (DHT)?

Promotes development of male external genitalia, prostate, and male secondary sexual characteristics.

What is the embryologic origin of the ovaries and testes?

Genital ridges derived from intermediate mesoderm.

What is the embryologic origin of the external genitalia?

Genital tubercle, urogenital folds, and labioscrotal swellings.

What structures develop from the genital tubercle?

Penis in males and clitoris in females.

What is the function of Sertoli cells?

Support spermatogenesis, secrete inhibin B and anti-Müllerian hormone, and respond to FSH.

What is the function of Leydig cells?

Produce testosterone in response to LH.

What is the function of inhibin B?

Secreted by Sertoli cells; inhibits FSH secretion.

What stimulates spermatogenesis?

FSH acting on Sertoli cells and testosterone produced by Leydig cells.

What is the hormonal pathway controlling the menstrual cycle?

Hypothalamic GnRH stimulates pituitary FSH and LH, which regulate ovarian estrogen and progesterone production.

What is the main function of FSH in females?

Stimulates granulosa cell growth and aromatase activity, promoting estrogen synthesis.

What is the main function of LH in females?

Stimulates theca cells to produce androgens and triggers ovulation and corpus luteum formation.

What triggers ovulation?

The midcycle LH surge, stimulated by sustained high estrogen levels.

What hormone dominates the follicular phase?

Estrogen.

What hormone dominates the luteal phase?

Progesterone, produced by the corpus luteum.

What causes menstruation?

Regression of the corpus luteum causes progesterone and estrogen levels to fall, leading to endometrial shedding.

What is the function of progesterone during the menstrual cycle?

Promotes secretory transformation of the endometrium and supports implantation.

What is the function of prolactin?

Stimulates milk production; elevated levels suppress GnRH and can cause amenorrhea.

What is the function of oxytocin in reproduction?

Stimulates uterine contractions and milk ejection.

What is Klinefelter syndrome?

47,XXY; primary testicular failure with small testes, infertility, gynecomastia, and increased FSH and LH.

What is Turner syndrome?

45,X; streak ovaries, short stature, webbed neck, and primary amenorrhea with elevated FSH and LH.

What is Kallmann syndrome?

Impaired GnRH neuron migration causing hypogonadotropic hypogonadism and anosmia or hyposmia.

What is androgen insensitivity syndrome?

46,XY individual with defective androgen receptors, female external genitalia, breast development, scant body hair, and absent uterus.

Why is the uterus absent in androgen insensitivity syndrome?

Testes produce anti-Müllerian hormone, causing Müllerian duct regression.

What is congenital adrenal hyperplasia's effect on a 46,XX fetus?

Excess adrenal androgens cause virilization of external genitalia.

What is the characteristic presentation of Müllerian agenesis?

46,XX individual with normal ovaries and breasts but absent uterus and upper vagina.

What causes polycystic ovary syndrome (PCOS)?

Ovarian steroidogenesis dysregulation with increased LH relative to FSH, increased androgens, and impaired follicular maturation.

What are the diagnostic features of PCOS?

At least two of: oligo-/anovulation, hyperandrogenism, and polycystic ovaries on ultrasound.

What are common clinical features of PCOS?

Irregular menstruation, infertility, hirsutism, acne, obesity, insulin resistance, and acanthosis nigricans.

Why does PCOS increase endometrial cancer risk?

Chronic anovulation causes unopposed estrogen stimulation of the endometrium.

What is endometriosis?

Ectopic endometrial tissue, commonly causing cyclic pelvic pain, dysmenorrhea, dyspareunia, and infertility.

What is adenomyosis?

Endometrial glands and stroma within the myometrium, often causing painful, heavy menstruation and an enlarged uterus.

What is leiomyoma?

Benign uterine smooth muscle tumor associated with heavy menstrual bleeding, pelvic pressure, and infertility.

What is endometrial hyperplasia associated with?

Unopposed estrogen exposure, including obesity and chronic anovulation; it increases endometrial carcinoma risk.

What is the major risk factor for cervical squamous cell carcinoma?

Persistent infection with high-risk HPV, especially types 16 and 18.

Which HPV types are most associated with cervical cancer?

HPV 16 and 18.

Which HPV types are most associated with genital warts?

HPV 6 and 11.

What is the classic presentation of cervical cancer?

Postcoital bleeding or abnormal vaginal bleeding.

What is the most common type of ovarian epithelial cancer?

Serous cystadenocarcinoma.

What is the association of ovarian dysgerminoma?

Germ cell tumor associated with elevated LDH and sometimes elevated hCG.

What is the characteristic marker of ovarian yolk sac tumor?

Alpha-fetoprotein (AFP).

What are the characteristic features of a granulosa cell tumor?

Estrogen production and Call-Exner bodies; may cause endometrial hyperplasia.

What is the most common cause of anovulatory infertility?

Polycystic ovary syndrome.

What is placenta previa?

Placenta implants over the internal cervical os, causing painless vaginal bleeding in the third trimester.

What is placental abruption?

Premature separation of the placenta, causing painful vaginal bleeding and a tender uterus.

What is placenta accreta?

Abnormal placental attachment directly to the myometrium without invading it.

What is placenta increta?

Placental villi invade into the myometrium.

What is placenta percreta?

Placental villi penetrate through the myometrium and serosa, potentially invading adjacent organs.

What are major risk factors for placenta accreta spectrum?

Prior cesarean section or uterine surgery, placenta previa, advanced maternal age, and multiparity.

What is vasa previa?

Fetal blood vessels run over or near the internal cervical os, risking fetal hemorrhage after membrane rupture.

What is the classic presentation of vasa previa?

Painless vaginal bleeding after rupture of membranes with fetal heart rate abnormalities.

What is the difference between 1° and 2° hypogonadism?

Primary gonadal failure causes low sex hormones with high LH/FSH; secondary hypogonadism causes low sex hormones with low or inappropriately normal LH/FSH.

What is the characteristic presentation of benign prostatic hyperplasia?

Urinary hesitancy, weak stream, incomplete emptying, and nocturia due to periurethral prostate enlargement.

What is the mechanism of finasteride?

Inhibits 5-alpha-reductase, reducing conversion of testosterone to DHT and shrinking the prostate.

What is the mechanism of tamsulosin?

Blocks alpha-1A receptors in the prostate and bladder neck, relaxing smooth muscle and improving urine flow.

What is the classic presentation of prostate cancer?

Usually peripheral-zone malignancy, often detected by elevated PSA or a hard, irregular prostate on examination.

What is the most common type of testicular cancer in young men?

Germ cell tumor.

What is the characteristic presentation of testicular torsion?

Sudden severe testicular pain, high-riding testis, and absent cremasteric reflex; requires urgent surgical management.

What is the characteristic presentation of testicular cancer?

Painless testicular mass that does not transilluminate.

What is a hydrocele?

Fluid accumulation around the testis that typically transilluminates.

What is a varicocele?

Dilated pampiniform plexus veins, classically described as a bag of worms and more common on the left.