Development Of The Reproductive Tract

Question 1

What is the earliest thing to happen to germ cells in development?

Answer 1

Germ cells separate early in development and find their way to the primordial gonads which develop into ovaries in the females and the testes in the male

Question 2

What are some of the organs that are involved in the control of reproductive proccesses?

Answer 2

The hypothalmus, the anterior and posterior pituarity gland, the gonads and the placenta produce the hormones that are involved in reproductive processes

Question 3

What does the hypothalamus produce that are involved in the control of reproductive processes?

Answer 3

Peptide releasing factors, GnRh (gondatropin releasing hormone) PRH (prolactin releasing hormones) and prolactin inhbiting hormone

Question 4

Which of the reproductive hormones are produced at the posterior pitaurity gland?

Answer 4

Produces oxytocin through neural control of the hypothalmus,

Question 5

What are the reproductive hormones that are produced at the anterior piturity gland?

Answer 5

Produces teh gonadotropins, FSH (follicle stimulating hormone) and Lh (leutinising hormone) and prolactin

Question 6

Which of the reproductive hormones are produced at the gonads?

Answer 6

The gondal steriods, in the male testorone in the female oestrogen,

Question 7

What are the hormones produced by the placenta?

Answer 7

Produces human chrononic gonadtopin, human placental lactogen and progesterone

Question 8

What is the urogenital ridge?

Answer 8

A region of intermediate mesoderm giving rise to both the embroyonic kidney and the gonad

Question 9

What do the gonads intially appear as?

Answer 9

Dervived from the intermediate mesoderm and the primodial germ cells, and appear intitally as a pair of longitudinal ridges, the gential and the gondal ridges

Question 10

When do germ cells appear in the genital ridges?

Answer 10

The 6th week of development

Question 11

How do the primodial germ cells end up at the primitive gonads?

Answer 11

Originate in the epiidblast, migrate through the primitive streak and by the third week reside among the endoderm cells, and during the 4th migrate by ameboid movement aong the dorsal mesentery off the hindgut and arrive at the primitive gonads

Question 12

What are the genetic features that determine a male?

Answer 12

Male gamete carries a Y chormonsome, a a SRY gene on the short arm is a transcription factor that initiates a downstream cascade, and is a testis determining factor, as under its influence the testis development occurs

Question 13

What are the genetic factors determine the formation of a female?

Answer 13

Absence of they chromsome leads to development of female, including the gonad (the ovary) and the internal and the external gentilais

Question 14

What happens under Y influence?

Answer 14

Medullary cord develops, no cortical cords, and the thick tunica albugenia

Question 15

What happens without Y influence?

Answer 15

The medulllary cord degenerates, the cortical cord develop and there is no tunica albuginea

Question 16

Where can the primodial germ cells be found?

Answer 16

The cortex

Question 17

What are some of the features of the urogenital sinus?

Answer 17

Created from the hindgut by the urorecta septum, is continous with the umbilcus and urachus and the median umbilical ligmanent.

Question 18

What happens to the mesonephric ducts in males?

Answer 18

The mesonephric ducts reach the urogenital sinus, uteric bud sprouts form the mesonephric ducts, the smooth musculature begins to appear and the urogenital sinus begins to exapn, and the uteric tubule and the mesonephric ducts make the indepnedant oepning in the UGS causing the prostate and the prostatic urethra to be formed

Question 19

What happens to the mesonephric ducts in females?

Answer 19

mesonephric ducts reach the urogenital sinus, the uteruc bud sprouts and the UGS expands as the mesonephric duct regresses, and this continues as the uteric bud opens to the urogential sinus

Question 20

how does the vagina develop?

Answer 20

two solid invaginations grow out of the pelvic part of the sinus, form a vaginal plate, proliferation increases at the cranial end of plate and the lymen of vagina reains suspened by a thin tissue plate known as the hymen

Question 21

What is the fate of the ducts in males?

Answer 21

the testis developes, so androgen secretion supports the mesonephric duct, and testis secretes Mullerian inhibiting substance that causes the paramesonephric duct to regress

Question 22

what is the fate of the duct in females?

Answer 22

there is no andrgoen secretion, so the mesonphric duct degenerates, and there is also known testis derivived mullerian inhibitng substance

Question 23

what are the features of the external genitalia at the indifferent stage?

Answer 23

the gential tubercule, the genital folds and the genital swellings

Question 24

what happens to the indifferent genitlia in males under the influence of the testis derivied hormones?

Answer 24

the gential tubercule elognates and the genital folds fuse to form the spongy urterthra, urethral folds fuse to form the shaft of the penis, gneital swellings fuse to form the scrotum and gential tubercule expands to form the glans penis

Question 25

what hormone influences the development of the external genitia in males?

Answer 25

dihyrdotesterone

Question 26

what happens to the indifferent external gentilail in females?

Answer 26

there is no fusion and hte urethra opens into the vestibule, the urethral folds and the gential swellings form the labia minora and majora and the gential tubercule forms the clitoris

Question 27

where does the testis arise and how is it tethered to the labiosacral folds?

Answer 27

arises in the upper lumbar region, and is tethered to the labiosacral folds by the gubernaculum

Question 28

what is the vestigal remenant of the gubernaculum?

Answer 28

the scrotal ligament

Question 29

how do the ovaries descend in the female?

Answer 29

oringally on the posterior abdominal wall, guberculum attaches the ovary to the labioscaral folds, to become the ovarian ligament and the round ligament of the uterus