Development and teratology of reproductive system.
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•Anna Mac Gillavry
•11.04.2022




www.dailykos.com



Development of gonad
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•indifferent gonad
•    to 6th-7th week of    development
–germ cell (wall of yolk sac)
–genital (gonadal) ridge – mesoderm
–coelomic epithelium – mesoderm – primitive sex cords
http://quizlet.com/15832386/tamhsc-development-of-genital-system-flash-cards/

A. paramesonephric (Mullerian) duct, B. urogenital sinus, C. gonads, D. mesonephros, E. mesonephric
tubules, Mesonephric (Wolffian) Duct
A. genital ridge, B. hindgut, C. cloaca, D. mesonephros, E. genital ridge




Development of genital ducts
•indifferent stage
–mesonephric duct (Wolffian)
–paramesonephric duct (Müllerian) – longitudinal invagination of coelomic epithelium at the
urogenital cord

Differentiation
–towards male sex
•towards female sex
mesonephric duct – Wolff
paramesonephric duct - Müller
- vertical
- horizontal do not fuse →uterine tube
- vertical - both ducts fuse → uterovaginal primordium  – uterus and cranial part of vagina

Development of external genitalia
•indifferent stage
–cloacal folds around the cloacal membrane →anteriorly urethral (urogenital) folds
–    →posteriorly anal folds
–genital tubercle (phallus)
–genital swellings
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cloacal membrane

Development of external genitalia - differentiation
anal membrane
urogenital membrane
- genital tubercle →clitoris
- urethral (urogenital) folds    →labia minora
- genital swellings (tori genitales) →labia maiora
FEMALE
MALE
- genital tubercle →penis
- urogenital folds fuse →pars spongiosa urethrae m.
- genital swellings fuse →scrotum

Disorders of sexual development
„hermaphrodites“
•Ambigous genitalia: clitoral hypertrophy/small penis with hypospadia •Ovotestes – less than 1 in
20000 in 70 % of cases, the caryotype is 46, XX
•Genotype does not match the phenotype
•– congenital adrenal hyperplasia, most common cause;
-androgen insensitivity syndrom (AIS): complete (CAIS), mild (MAIS) or partial (PAIS)
-5-a-reductase deficiency – affects males

Chromosomal abberations
•Klinefelter syndrom – 47, XXY (XXXY…) – 1 in 1000 males: decreased fertility, small testes,
decreased testosteron levels, gynecomastia in app. 33%
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•Gonadal dysgenesis – oocytes are absent:
-Swyer syndrome – XY female gonadal dysgenesis – point mutation or deletions of the SRY gene
-Turner syndrome – 45, X

Hernias and cryptorchidism
•Congenital inderect inguinal hernia
•Hydrocele of the testis and/or spermatic cord
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•Cryptorchidism

Uterine and vaginal defects
•Duplication of the uterus
-uterus didelphys
-uterus bicornus
-uterus arcuatus
•Uterus bicornus unicollis
•Cervical atresia
•Vaginal atresia

Defects in male genetalia
•Hypospadia – 3 to 5 in 1000 births
•Epispadia – 1 in 30000 – most often associated with extrophy of the bladder and abnormal closure
of the ventral body wall •Micropenis – insufficient androgen stimulation – primary hypogonadism,
hypothalamic or pituitary disfunction
•Bifid penis