Urogenital Development (6)

Question 1

kidney development

Answer 1

1. pronephroi (week 4)
2. mesonephroi (week 4) aka embryological kidney for 4 weeks
3. metanephroi (dev week 5, function by 9) aka adult kidneys

Question 2

mesonephroi ducts

Answer 2

drain the mesonephroi but after degeneration (12) ducts remain and develop in males

Question 3

metanephroi development

Answer 3

ureteric bud + metanephrogenic blastema

initial growth from bud
bud is outgrowth of mesonephric duct

Question 4

adult derivatives

other kidney parts

Answer 4

stalk > ureter
cranial bud > collecting tubules > major and minor callices

fetal kidney has lobes dissapear in 1st year

Question 5

renal agenesis

Answer 5

kidneys not develop so either unilateral or bilateral

if bilateral assoc w/ oligohydramnios and death

oppo of polyhydramnios, little/no amniotic fluid

Question 6

horseshoe kidney

Answer 6

fusion at the poles so kidneys can’t rise

higher in males and females with turner’s syndrome

Question 7

ectopic ureter

Answer 7

ureter in the ductus deferens/seminal gland/urethra/vagina = incontinence

Question 8

urogenital sinus parts

Answer 8

1. vesical- forms bladder and allantois
2. pelvic- forms urethra
   -males = membranous and prostatic only
   -females = entire
3. phallic- primordium of penis or clitoris and spongy urethra in males

glans penis from ectoderm instead of endo

Question 9

bladder development

Answer 9

1. bladder and allantois initially continous
2. allantois constricts > urachus
3. mesonephric ducts incorporated into dorsal wall of bladder

Question 10

bladder locations

Answer 10

birth-6 yr = abdominal organ
6-puberty = greater pelvis
adult = lesser pelvis

Question 11

urachal sinus

allantois closure problems

Answer 11

allantois doesn’t close fully so urine flow out of umbilicus

Question 12

urachal fistula

allantois closure problems

Answer 12

allantois doesn’t close at all so free flow out of umbilicus

Question 13

urachal cyst

allantois closure problems

Answer 13

allantois closes but urine becomes trapped in a pouch

Question 14

gonad development

Answer 14

1. primordial germ cells from yolk sac
2. undifferentiated until week 6-7 with cortex and medulla
3. cortex > ovary (medulla regress) and medulla > testis (cortex regress)

Question 15

testes development

Answer 15

• XY genotype
  1. SRY gene on Y starts testicular dev by **turning off **Wnt4, Foxl3, Fst, Rspo1 = inhibit ovarian dev
  2. hormones produced for functional dev
  -testosterone, DHT, AMH
  3. testes cordoned off from mesonephros by thick tunica albuginea
  4. AMH inhibits paramesonephric
  5. seminiferous tubules produce sperm @ puberty

Question 16

ovary development

Answer 16

XX genotype
1. Wnt4, Foxl2, Fst, Rspo1 genes make functional
2. must have two X for functional dev
3. separated from mesonephros by thin tunica albuginea
4. no oogonia postnatally

no hormones needed

Question 17

genital ducts

males

Answer 17

testosterone stimulates mesonephric ducts > ductus deferens, seminal vesicles, ejac ducts

AMH degenerates paramesonephric duct

prostate and bulbourethral glands outgrowth of urethra (urogenital sinus)

Question 18

genital ducts

females

Answer 18

no testosterone = mesonephric dissapear
no AMH = paramesonephric ducts dev

estrogens from mother stim dev of uterine tubes + uterus + superior vagina from paramesonephric

greater vestibular glands and paraurethral glands form from urogenital sinus

Question 19

external genitalia

male

Answer 19

induced by testosterone

phallus enlarges/elongates = penis and encloses spongy urethra

labioscrotal swellings fuse = scrotum

Question 20

external genitalia

female

Answer 20

NOT hormonally induced

phallus shrinks = clitoris
urethral folds separate = labia minora
labioscrotal swellings stay separated = majora

Question 21

ovotesticular DSD

Answer 21

non functional sex organs
ambiguous external

have both testicular and ovarian tissue

Question 22

XX DSD

Answer 22

female fetus exposed to excessive androgens (steroids) = functional ovaries but masculine external

Question 23

XY DSD

Answer 23

inadequate testosterone and AMH by fetal testes = variable external

Question 24

androgen insensitivity syndrome

aka testicular feminization syndrome

Answer 24

XY genotype resistant to testosterone

typical female appearance but vagina ends in blind pouch

testes present and ovaries absent, no menses

testes removed for cancer prevention

Question 25

mixed gonadal dysgenesis

Answer 25

XY genotype
testis on one side + undifferentiated gonad on other side

internal female (uterus) but external range

at puberty no breasts or menses but masculinization may occur

Question 26

5-alpha-reductase deficiency

Answer 26

normally converts testosterone to DHT

XY genotype so typical male internal

external variable but often female pre-puberty > male sex characteristics dev at puberty so indiv identifies as male

very rare

Question 27

hypospadias

penile disorders

Answer 27

external urethral orifice on central surface of glans penis or body

Question 28

epispadias

penile disorder

Answer 28

external orifice on dorsal surface of penis

assoc w/ bladder exstrophy

Question 29

bifid penis

penile disorders

Answer 29

assoc w/ bladder exstrophy and bifid anus

Question 30

micropenis

penile disorder

Answer 30

fetal testicular failure and hypopituitarism (low hormones)

Question 31

agenesis of external genitalia

Answer 31

failure of genital tubercule to dev so urethra opens into perineum near anus

absence of vagina/uterus from failure of sinovaginal bulbs to dev

Question 32

uterine abnormalities

Answer 32

1. double uterus
2. rudimentary horn
3. septum dividing uterus
   4.

Question 33

hymen abnormalities

Answer 33

1. incomplete perforation
2. septate hymen
3. cribiform (small dots)
4. microperforate
5. imperforate