Week 3 - E - Embryology - Reproductive system Flashcards
The male and female reproductive systems develop initially embryonically “indifferent” What is it that causes the reproductive systems to become different?
It is the product of the sex-determining region Y (SRY) gene - this is on the Y chromosme (also known as Testis determing factor (TDF) ) - this is what makes the difference
Under the influence of the Y chromsome, it will cause the testis to develop (Tetsis-determing factor gene) and in its absence ovaries will develop The primitive sex cords present in the indifferent stage will now develop WHat do they become in males?
IN males the primitive sex cords become testis/medullary cords
What is it that causes the primitive sex cords to become the testis/medullary cords?
This is the action of the Sex determing region Y (SRY) gene that causes the cords to develop into tesits/medullary cords
What do the medullary cords in the man become? WHat cords are formed instead in females? What happens to the primitive sex cords in the female?
The medullary cords become the seminiferous tubules in the male The cords formed in females instead are the cortical cords and the primitive sex cords degenerate The cortical cords go on to form the ovarian follicles
After the formation of the testis in males, what do they produce and what effect does this have?
Testis produce Anti-mullerian hormone (Mullerian inhibitng hormone/substance) and tesosterone Anti-mullerian hormone suppresses the development of the Mullerian Duct Testosterone stimulates the development of the Wolffian Duct to form vas deferenes, epididymis and semiinal vesicles
What cells in the testis produce testosterone and anti-mullerian hormone?
The Leydig cells produce testosterone The Sertoli cells produce anti-mullerian substance
What are the Wolffian and Mullerian ducts also known as? Testosterone is aslo converted to dihydrotestosterone in males, what does this cause the devlopment off?
Woffian duct - Mesonephric duct - males
Mullerian duct - Paramesonephric duct - females
Dihydrotesosterone causes the development of external genitalia in the male - eg penis, scrotum and prostate gland
At the end of feotal development, the testis should descend from the posterior abdominal wall and into the scrotum WHat structure aids in the descent of the testis?
The gubernaculum aids in the descent of the gonads
Female development * Degeneration of primitive cords * Development of Cortical Cords * Descent of Ovaries * Development of the Uterus * Ligaments of the ovary What is produced by the ovary (and maternal and placental sources) that helps with the female embryological development?
Oesotgens are produced which aid in the female embryological development
What does the production of oestrogen cause for the embryo?
Oestrogen - stimulates paramesonephric ducts Also causes the formation of the external genitalia - labia, clitoris, lower portion of vagina
What do the paramesonephric ducts become when stimulated?
The paramesonephric ducts become the uterine tubes, uterus and upper 1/3rd of the vagina
As the paramesonephric ducts fuse they create a peritoneal fold that attaches the uterus, fallopian tubes, and ovaries to the pelvis, what is this double layer of peritoneal fold known as?
This peritoneal fold is known as the broad ligament of the uterus - it attaches the uterus, fallopian tubes and ovaries to the pelvis
The broad ligament helps maintain the uterus in its position
The round ligament of the uterus is not peritoneal structure but is in fact formed form an embryological remnant What is this remnant? What covers the proximal part of the round ligament of the uterus? The function of the round ligament is maintenance of the anteversion of the uterus
The gubernaculum becomes the round ligament of the uterus The proximal part of the round ligament is covered by the broad ligament of the uterus
The uterus develops from the paramesonephric ducts, as do the uterine tubes and upper 1/3rd of the vagina due to oestrogen OStrogen also causes the development of external genitalia What embryological structure becomes the lower 1/3rd of the vagina?
The sinovaginal bulbs become the lower 1/3rd of the vagina - these bulbs also form the hymen
What ligament attaches the ovary to the lateral wall of the uterus? What ligament attaches the ovary to the pelvic wall? What is the portion of the broad ligament of the uterus that suspends the ovaries. known as?
Overian ligament (proper ovarian ligament) attaches the ovary to uteus Suspensory ligament of the ovary attaches the ovary to the pelvic wall The portion of broad ligament that suspends the ovaries is known as the mesovarium
In animal anatomy, a cloaca is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts The cloaca basically forms the reproductive, urinary and anal openings. What do the cloacal folds form cranially?
They cloacal folds fuse cranially in the 3rd week of development to form the genital tubercle - goes on to form clitoris or glans of penis
The common origin of the urogenital system and the rectum/anal canal means that there may be connections and fistulae between them
State what is for the black and red box
Black pox - pointing to a urorectal fistula
Red box - pointing to a rectoperineal fistula
