Development of Urinary system and reproductive system 1. Development of kidney and ureter 2. Development of urinary bladder and urethra 3. Abnormality in urinary system 4. Development of gonad 5. Development of reproductive tracts 6. Abnormality in reproductive system

Head segmentation Nephrotome → 3rd week: Head segmentation Nephrotome → Intermediate Pronephros Mesoderm Other migration, proliferation Nephrogenic cord → Mesonephros and Metanephros

Intermediate mesoderm 3rd week Nephrogenic cord Urogenital ridge Intermediate mesoderm ─────→ ───→ Intermediate mesoderm Mesonephric ridge Gonadial ridge Urinary system, Genital excurrent ducts Gonad ─── Pudendum

Mesonephric ridge Urogenital ridge Gonadial ridge

Mesonephric ridge Gonadial ridge

Development of urinary system Development of kidney and ureter 1. Pronephros 4th week Nephrotome (7-14th Somite) Pronephric tubule Pronephric duct Degeneration in 1 week Mesonephric duct

Destiny: degeneration Pronephric tubule Pronephros Time：4th week Function：no Destiny: degeneration

2. Mesonephros 14-18th somite Middle part of nephrogenic cord 80 transverse S-shaped tubule Mesonephric tubule Mesonephric duct Continus to pronephric duct Inner end form renal capsule Glomerulus Outer end bind to mesonephric duct The end bind to cloaca

Time： Function: Destiny: transient urinary Most degeneration, end of 4th week Function: transient urinary Destiny: Most degeneration, Small part form male excurrent duct Mesonephric duct Mesonephric tubule

3.Metanephros Time：begin at 5th week, Function：begin at 3th month, exist forever Function：begin at 3th month, urinary function Position：rise gradually Metanephros

End of mesonephric duct （adjacent to cloaca） Origin one Ureteric bud Prolong Ureter Embranchment ＞12 Renal pelvis, renal calyce （The end branched as T） Collecting tube

+ Origin two Metanephrogenic blastema Cap-shaped cell cluster (Mesoderm of the mesonephric ridge) Metanephrogenic blastema Cap-shaped cell cluster S-shaped tubule Bind to collecting tubule Renal capsule Glomerulus + Renal tubule Renal corpuscle Nephron

Metanephrogenic blastema Mesonephric tubule Collecting tubule Renal pelvis Renal calyce Ureteric bud

Formation and rising of metanephros

Development of urinary bladder and urethra Male Female Upper： Middle: Lower: Urinary bladder Upper part of urethra Lower part Urethra Vestibule of vagina Urogenital sinus Anorectal canal 4-7th week Urorectal septum Cloaca

Evolvement of male urogenital sinus B C D E

Positional evolvement of Ureter and Mesonephric duct

Abnormality 　Double ureter 　Urachal fistula 　Exstrophy of bladder 　Polycystic kidney 　Horseshoe kidney 　Single kidney

Polycystic kidney

Horseshoe kidney

Single kidney Right single kidney Left single kidney

Ectopic kidney

Double ureter Ureter

Urachal fistula

Exstrophy of bladder

Development of gonad Gonad differentiation at 7th week Developmental stage： Sex undifferentiated stage→ Sex differentiated stage Reproductive tracts：２ → １ Proper current： → Feamle

Endoderm cells of yolk sac Development of gonad Endoderm cells of yolk sac 4th week Proliferation, differentiation Primordial germ cells 6th week Migration in one week １.Development of undifferentiated gonad Gonadial ridge 6th week Primary sex cord Superficial epithelium →cell cords

Large and round endoderm cells in yolk sac Primordial germ cells Large and round endoderm cells in yolk sac

Migration of primordial germ cells 6th week

Histocompatibility Y antigen H-Y antigen determine the differentiation to testis The gene of H-Y antigen located at Y chromosome The cell membrane of the cell which sex chromosome is XY possesses H-Y antigen Primary sex cord H-Y antigen proliferation seminiferous tubule

２. Development of testis Primary sex cord (H-Y antigen) 7th week Separated from surface Mesenchymal cell Interstitial cell Cells of sex cord Primordial germ cells Sustantacular cell Spermatogonium + + Testis

３. Development of ovary Superficial epithelium + + Primary sex cord Secondary sex cord (cortical cord) Primary sex cord (No H-Y antigen) After 10th week Primordial follicle 16th week Mesenchymal cells Stroma Degeneration Cells of sex cord Primordial germ cells Ovary + + Follicular cells Oogonium

Cortex Medulla Cortical Cord Ovary Testis Rete testis Tubule rectus Follicle Seminiferous tubule

Ovary Testis Rete testis Primary oocyte Follicular cell Follicle Tubule rectus Follicle Seminiferous tubule Spermatogonium Primary oocyte Sustantacular cell Follicular cell Follicle Seminiferous tubule

４. Descend of testis and ovary Embryo →lengthen Gubernaculum →shorten 7th to 8th month → Scrotum

Paramesonephric tubule Development of reproductive tracts 1. Undifferentiated stage: Mesonephric tubule Gonad Mesonephric duct Paramesonephric tubule Sinus tubercle Urogenital sinus B. Female A. Male

Paramesonephric duct： Mesonephric ducts and tubules ２. Differentiation of female reproductive tract End of upper segment：Fimbria Upper and middle segment：oviduct Lower segment： Uterus End： Vaginal fornix Paramesonephric duct： Sinus tubercle： Vaginal plate Vagina Mesonephric ducts and tubules Degeneration

3. Differentiation of male reproductive tract Head ── Epididymal duct Tail ── Spermaduct Metanephric duct Most of →degeneration Some of → Efferent ducts Mespnephric tubules Paramesonephric duct Degeneration

Ovary Testis Urogenital sinus Urogenital sinus Oviduct Spermaduct Uterus Vaginal plate Efferent duct Epididymal duct

Abnormality of reproductive system 1. Cryptorchidism 2. Congenital inguinal hernia 3. Double uterus 4. Vaginal atresia 5. Hypospadias 6. Hermaphroditism

Cryptorchidism

Congenital inguinal hernia

Double uterus

Vaginal atresia

Hypospadias

Hermaphroditism