EMB-Genitals Flashcards
what are the mesonephric and paramesonephric ducts derivatives of?
intermediate mesoderm
what arises from the endoderm in the genitals?
anything that comes from the urogenital sinus
what is the function of SRY?
acts on stromal support cells –> testes formation –> sertoli cells –> leydig cells –> testosterone (internal male development) –> DHT (external male genetalia)
what is responsible for sex determination?
+SRY male
-SRY female
describe the development of the mesonephric duct in males
SRY –> testes –> leydig cells–>testosterone –> supports growth of mesonephric duct
describe the development of the paramesonephric duct in males
SRY –> testes –> sertoli cells –> AMH (aka MIS) –> paramesonephric duct regresses
describe the development of the mesonephric duct in females
no SRY –> no testes –> no leydig cells –> no testosterone –> mesonephric duct regresses
describe the development of the paramesonephric duct in females
no sry –> no testes –> no sertoli cells –> no AMH –> paramesonephric duct persists
what arises from somatic support cells, primordial germ cells, and mesenchyme of females? (in that order)
follicle cells
oocytes
paramesonephric duct
what are the derivatives of the paramesonephric duct?
Fallopian tubes
Uterus (and cervix)
Vagina (upper 1/3)
what is the contribution of the urogenital sinus in females? what germ layer is this?
bulbourethral glands
greater vestibular glands
lower 2/3 of vagina
membranous urethra
endoderm!
how does the external genitalia come about
proliferation of mesoderm and ectoderm around the clocal membrane produces primordial tissues of the genitalia
what week does external genetal formation start?
week 7
when can you tell male from female external genetalia
week 12
what is DHT responsible for in males
lengthening of genital tubercle and fusion of labioscrotal swellings –> penis growth
what is estradiol responsible for in females?
external female development
what arises from somatic support cells, primordial germ cells, and mesenchyme of males? (in that order)
sertoli cells
spermatagoina
mesonephric duct
what structures are derived from the mesonephric duct?
SEED seminal vesicle ejaculatory duct epididymus ductus deferens
what are the contributions of the urogenital sinus in the male? what germ layer is this?
prostate
prostatic urethra
bulbourethral gland
endoderm
what does the genital tubercle form in the male?
glans penis
body of penis
corpus cavernosum
corpus spongiosum
what does the genital tubercle form in the female?
glans clitorus
what do the genital folds form in the male?
ventral penis
penile raphe
what do the genital folds form in the female?
labia minora
what are the labioscrotal swellings in male?
scrotum
scrotal raphe
what are the labioscrotal swellings in female?
labia majora and mons pubis
what forms the ovarian and uterine ligaments
superior and inferior gubernaculum
what is the male homolog to the glans clitoris?
glans penis
what is the male homolog to the vestibular bulbs?
corpus spongiosum and cavernosum
what is the male homolog to the greater vestibular glands?
bulbourethral gland
what is the male homolog to the urethral and paraurethral glands?
prostate
what is the male homolog to the labia minora?
ventral shaft
what is the male homolog to the labia majora?
scrotum
newborn has normal male external and internal genitalia, however it is also found he has a small uterus and some fallopian tubes. how can this be?
he has persistant mullerian duct syndrome
caused by a mutation in AMH or its receptor
males normal stuff happens but the paramesonephric duct persists
patient comes in and looks like a lady with secondary female sex characteristics and female external genitalia but has male genetics. The vagina is short and has a blind end. it is also found they have small testis in the labial region. why is this?
they have androgen insensitivity
lack of testosterone/DTH sensitivty inhibits male external genitalia and makes internal genitalia rudimentary.
they still produce AMH from the sertoli cells so the paramesonephric duct is inhibited
baby is born with ambiguous genitalia and normal male internal genitalia. how can this occur?
5a reductase deficiency.
no conversion of testosterone to DHT –> external doesnt develop but internal still does cause testosterone
a female genotype comes out with ambiguous genitalia, she also has enlarged adrenal glands, why
21a hydroxylase deficiency, no cortisol –> more ACTH –> adrenal hyperplasia
also too many androgens causing weak virilization
what causes a septate uterus?
incomplete resorption of uterine septum
what causes a bicornate uterus
incomplete fusion of the paramesonephric ducts
what causes uterus didelphys?
complete lack of fusion of paramesonephric ducts
what causes hypospadias and what is it? associated with?
urethra opens in ball side of penis
incomplete closure of urogenital folds
cryptorchidism
what is epispadias? what causes? associated with?
urethra opens on outward side of penis
improper positioning of the genital tubercle
extrophy of bladder
