Genitalia Development Flashcards
Intermediate Mesoderm Contributions
Nephrogenic Cord Urogenital Ridge Mesonephric Duct Paramesonephric Duct Leydig Cells Thecal Cells
Epiblast Contributions
Primordial Germ Cells
Oocytes and Spermatogonia
Coelomic Epithelium (Somatic Support Cells) Contributions and Germ Layer Type
Somatic Lateral Plate Mesoderm
Makes Sertoli and Follicular Cells
SRY Gene Functions Male
Switch that turns on male differentiation cascade
Increases Leydig and sertoli cells and increases testis determining factor
Leydig Cell Sex Differentiation Function
Increases testosterone so mesonephric duct stays
causes male internal genitalia formation
causes increased DHT that induces male external genitalia
Sertoli Cell Sex Differentiation Function
Increases Anti-Mullerian Hormone so paramesonephric duct degenerates
stops female internal genitalia formation
SRY Gene Function Female
SRY is ABSENT in females
Leads to Thecal cells that cause mesonephric degeneration
Leads to Follicular cells that cause paramesonephric persistence
Urogenital Ridge Contributions
Primary Gonadal Cords
Testes
Ovaries
Paramesonephric Duct
Female Derivatives and Germ Layer Type
Broad L. of Uterus Uterine Tubes Fuses to become uterovaginal primordium Uterus (caudal end) Upper 1/3 of Vagina (cranial end)
Intermediate Mesoderm
Urogenital Sinus Female Derivatives (6) and Germ Layer Type
Membranous Urethra Urethral Glands Paraurethral Glands Greater/Lesser Vestiublar Glands Lower 2/3 of Vagina Vaginal Vestibule
Hindgut Endoderm
Vagina Development with Germ Layers
Uterovaginal Primordium (mesoderm) connects with urogenital sinus (endoderm) to form sinus tubercle
Induces formation of sinovaginal bulbs
Bulbs fuse to form vaginal plate
Plate undergoes recanalization to form vagina
Mesonephric Duct
Male Derivatives and Germ Layer Type
Appendix of Epididymis
Ductus Deferens
Seminal Vesicles
Ejaculatory Duct
Intermediate Mesoderm
Mesonephric Tubules
Male and Female Derivatives
Male: Efferent Ductules
Female: epoophoron, paroophoron
Urogenital Sinus Male Derivatives (5) and Germ Layer Type
Urinary bladder Prostatic Urethra Membranous Urethra Prostate Gland Bulbourethral Glands
Hindgut Endoderm
Navicular Fossa Formation
Surface ectoderm forms urethral plate in tip of spongy urethra
Recanalization forms fossa
Genital Tubercle
Male and Female Derivatives
Glans Penis
Glans Clitoris
Urogenital Folds
Male and Female Derivatives
Male: Lateral wall urethra, Spongy urethra, Penile raphe
Female: Labia minora frenulum
Labioscrotal Swellings
Male and Female Derivatives
Scrotum
Labia Majora
Ovarian and Uterine Ligaments Formation
Suspensory L. of Ovary from Cranial Gubernaculum
Round L. of Uterus from Caudal Gubernaculum
Broad L. of Uterus from Paramesonephric Duct
46 XY DSD
Has testes but phenotypically female
Caused by decreased testosterone, AMH or androgen insensitivity, 5-alpha reductase deficiency
Androgen insensitivity will cause blind end vagina and normal breast development but no utuers/menstruation
46 XX DSD
Has ovaries but masculinized external genitalia
Fused labia, clitoral hypertrophy and persistent urogenital sinus
Caused by excess androgen exposure to female fetus
Hypospadias
Type and Description
Glanular: incomplete urogenital fold fusion or navicular fossa solid
Penile: incomplete urogenital fold fusion
Penoscrotal: incomplete labioscrotal swelling fusion
Epispadias Description
Improper genital tubercle location with estrophy of bladder
