urogenital system development

kidneys formed by 3 overlapping systems

pronephros, mesonephros and metanephros

pronephros

forms in cervical region

mesonsphros

forms in thoracic region

metanephros

cloacal region

when do pronephros disappear

by the 4th week of development

what does mesonephros form

mesonephric duct (wolffian)

by week 6 the mesonephros forms a large ovoid structure with gonads developing along the medial edge becoming

urogenital ridge

when do mesonephros disappear

by week 10

metanephros called

permanent kidney

when do metanephros appear

in week 5

ureteric bud

outgrowth from duct near the cloaca

ureteric bud enters metanephric blastema and

forms primitive renal pelvis, major calyces and formation of collecting ducts

ureteric bud gives rise to

ureter, renal pelvis, major calyces, minor calyces and renal pyramids

metanephric blastema gives rise to

distal convoluted tubule, loop of henle, proximal convoluted tubule and bowman’s capsule

At 3 weeks the ____ appears

pronephros

At 5 weeks the ____ appears and ureteric bud enters ____ ___ and bifurcates

metanephros, metanephric blastema

what production begins at week 12

urine

what serves as a way to remove waste during development

placenta

ascent of kidneys caused by

lessening of body curvature and growth of body in lumbosacral region

urorectal septum

mesoderm that separates hindgut from urogenital sinus

posterior portion of cloaca is the

primitive anorectal canal

anterior portion of cloaca is

urogenital sinus

upper region of urogenital sinus

bladder

middle region of urogenital sinus

pelvic portion- urethra

lower portion of urogenital sinus

phallic part which depends on biological sex

in anatomic male, the mesonephric ducts become

vas deferens

as bladder grows, it absorbs ___ and ___

mesonephros and ureteric bud

epithelium of urethra originates in

endoderm

connective tissue and smooth muscle surrounding urethra comes from

visceral mesoderm

gonads develop as

gonadal ridges on the medial edge of mesonephric condensation

when do germ cells appear

week 6

when do gonads acquire gender characteristics

week 7

primitive sex cords

PGCs penetrate underlying mesenchyme and form irregularly shaped cords

what arises as longitudinal invagination of coelomic epithelium on urogenital ridge

mullerian ducts

what opens into urogenital sinus on either side of sinovaginal bulb and eventually degenerates and disappears

mesonephric ducts

upper part from mullerian duct fusion + lower part from urogenital sinus

vagina

mullerian ducts cranial

open to coelomic cavity

mullerian ducts horizontal

crosses mesonephros

mullerian ducts ventrical

fuses with mate at urogenital sinus

what grows to split anus and vagina

urorectal septum

the developing uterus will pull away from posterior abdominal wall to form

broad ligament of the uterus

the mullerian duct in males degenerates because of

anti-mullerian hormone that is produced by sertoli cells

mesonephric duct forms what in males

epididymis, ductus deferens and ejaculatory duct

what forms testis/medullary cords

primitive sex cords

leydig cells are found between

testis cords

when testis cords start producing testosterone

week 8

gubernaculum

mesenchymal condensation that connects testis to inguinal region

anterior cloacal folds

genital tubercle

middle cloacal folds

urethral folds

posterior cloacal folds

anal folds

female- genital swellings form

labia majora

male- genital swellings form

scrotum

external genitalia development in males stimulated by

androgens

external genitalia development in females stimulated by

estrogens

renal agenesis

pro/meso/metanephros sequence is not initiated or can occur because of renal dysplasia

unilateral renal agenesis

contralateral kidney at risk for abnormalities

bilateral renal agenesis

bilateral absence of kidneys

pelvic kidney

if one kidney fails to make it past the arterial fork

horseshoe kidney

if both kidneys are pushed close together during passage through the fork and fuse together

duplicate ureters result from

early splitting of ureteric bud

clitoral hypertorphy female

from excess androgens during development

ambiguous genitalia male

small penis with hypospadias

hypospadias

incomplete fusion of the urethral folds

complete androgen insensitivity

individuals develop a female external appearance, undescended tests in the pelvis and no uterus

androgen insensitivity syndrome

XY chromosomes, but cells do not respond to androgens produced by the gonads

uterus didelphys

full double uterus with double vagina from sinoatrial bulb failing to fuse

uterus arcuatus

slight indent

uterus bicornis

two horns entering a common vagina

vaginal atresia

when sinovaginal bulb fails to develop, a small pouch forms surrounding the cervix

congenital indirect inguinal hernia

intestinal loops enter the scrotum

cryptorchidism

non descent of testis/testes

cryptorchidism caused by

decreased androgen production