Development of the reproductive system

Collection of internal and external sex organs:

What is the reproductive system?

Early stage in the embryo:

When does the development of reproductive organs begin?

Intermediate mesoderm:

From what germ layer are the reproductive organs developed?

Mesonephric and paramesonephric ducts:

What embryonic structures precede the permanent adult reproductive organs?

Impossible to distinguish between male and female gonad:

What is the first stage of gonadal development known as?

Genital ridges:

What do gonads initially begin as?

Intermediate mesoderm and overlying epithelium:

From what are genital ridges derived?

Fourth week:

When do germ cells begin to migrate to the genital ridges?

Yolk sac:

Where do germ cells migrate from to reach the genital ridges?

Sixth week:

When do germ cells reach the genital ridges?

Combination of germ cells and primitive sex cords:

What forms the indifferent gonad?

Mesothelium, mesenchyme, primordial germ cells:

From what three sources are the gonads derived?

XY:

What sex chromosomes are present in a male embryo?

SRY gene:

What gene on the Y chromosome stimulates the development of testis cords?

Testis cords:

What do primitive sex cords form under the influence of the SRY gene?

Tunica albuginea:

What fibrous connective tissue layer forms around the testis cords?

Seminiferous tubules:

What do the testis cords become after acquiring a lumen during puberty?

Germ cells and Sertoli cells:

What two types of cells do the remaining testis cords contain?

Leydig cells:

What cells are located between the testis cords?

Testosterone:

What hormone do Leydig cells produce, and what does it drive?

XX:

What sex chromosomes are present in a female embryo?

Degenerate:

What happens to the primitive sex cords in a female embryo?

Cortical cords:

What cords are produced instead of testis cords in a female embryo?

Oogonium:

What does each cluster of cortical cords surround to form a primordial follicle?

Epithelial follicular cells:

What kind of cells surrounds each oogonium?

Mesonephric (Wolffian) and Paramesonephric (Müllerian) ducts:

What are the two pairs of ducts present in all embryos during early urogenital development?

Testosterone:

What hormone influences the mesonephric ducts to develop into male genital ducts?

Efferent ductules, epididymis:

What structures do the mesonephric ducts develop into in males?

Anti-Müllerian hormone:

What hormone causes the paramesonephric ducts to degenerate in males?

Sertoli cells:

What cells produce anti-Müllerian hormone in the testes?

Appendix testis:

What is the developmental remnant of the paramesonephric ducts in males?

Degenerate:

What happens to the mesonephric ducts in females due to the absence of testosterone?

Gartner’s duct:

What is the vestigial remnant of the mesonephric ducts in females?

Develop:

What happens to the paramesonephric ducts in females due to the absence of anti-Müllerian hormone?

Fallopian tubes:

What do the cranial and horizontal parts of the paramesonephric ducts become?

Uterus, cervix, upper 1/3 of the vagina:

What does the caudal part of the paramesonephric ducts form?

Sinovaginal bulbs:

What structure forms the lower 2/3 of the vagina?

Third week:

When does the development of the external genitalia begin?

Cloacal folds:

What is formed from mesenchymal cells migrating to the cloacal membrane?

Genital tubercle:

What do the cloacal folds fuse to form cranially?

Urethral folds:

What do the cloacal folds divide into caudally?

Androgens (dihydrotestosterone - DHT):

What drives the development of indifferent genitalia into male genitalia?

Phallus:

What does the genital tubercle become in males?

Urethral groove:

What is formed when the urethral folds are pulled?

Penile urethra:

What is formed when the urethral folds close over?

Scrotal swellings:

What do the genital swellings become in males?

Estrogens:

What hormone is responsible for external genital development in female embryos?

Clitoris:

What does the genital tubercle form in females?

Labia minora and labia majora:

What do the urethral folds and genital swellings form in females?

Vestibule:

What does the open urogenital groove form in females?

Gubernaculum:

What tethers the gonads to the scrotum or labia?

28th week:

Around what week do the testes pass through the inguinal canal?

33rd week:

Around what week do the testes reach the scrotum?

Lumbar aorta:

From where do the testicular arteries branch?

Scrotal ligament:

What is the adult remnant of the gubernaculum in males?

Urogenital sinus and vesico-urethral part of the cloaca:

From what does the prostate arise?

Skene’s glands:

What are the homologues of the prostatic glands in females?

Urogenital sinus:

From what does the bulbo-urethral glands in males, and Bartholin’s gland in the female arise?

Ovarian ligament and round ligament of the uterus:

What does the gubernaculum become in females?

Ovary:

What is the indifferent gonad in a female?

Testis:

What is the indifferent gonad in a male?

Ovarian follicles:

What does the cortex become in a female?

Seminiferous tubules:

What does the cortex become in a male?

Rete ovarii:

What does the medulla become in a female?

Rete testis:

What does the medulla become in a male?

Epoophoron and Paroophoron:

What are the remnants of the mesonephric tubules in females?

Efferent ductules of testis and Paradidymis:

What are the remnants of the mesonephric tubules in males?

Appendix vesiculosa:

What is the vestigial remnant of the mesonephric duct in females?

Appendix of epididymis:

What is the vestigial remnant of the mesonephric duct in males?

Duct of epoophoron:

What does the mesonephric duct become in females?

Duct of epididymis:

What does the mesonephric duct become in males?

Longitudinal duct (Gartner duct):

What is another name of mesonephric duct in females?

Ductus deferens and Ejaculatory duct:

What does the mesonephric duct become in males?

Hydatid (of Morgagni):

What does the Paramesonephric duct become in females?

Appendix of testis:

What does the Paramesonephric duct become in males?

Uterine tube, Uterus, Cervix:

What does the Paramesonephric duct become in females?

Urogenital sinus, Urethra, Vagina, Urethral and paraurethral glands, Greater vestibular glands:

What does the Urogenital sinus become in females?

Urinary bladder, Urethra (except navicular fossa), Prostatic utricle, Prostate, Bulbourethral glands:

What does the Urogenital sinus become in males?

Hymen:

What does the Sinus tubercle become in females?

Seminal colliculus:

What does the Sinus tubercle become in males?

Clitoris:

What does the Primordial phallus become in females?

Penis:

What does the Primordial phallus become in males?

Glans clitoris:

What does the Glans become in females?

Glans penis:

What does the Glans become in males?

Corpora cavernosa of clitoris:

What does the Corpora cavernosa become in females?

Corpora cavernosa of penis:

What does the Corpora cavernosa become in males?

Bulb of vestibule:

What does the Bulb become in females?

Corpus spongiosum of penis:

What does the Bulb become in males?

Labia minora:

What does the Urogenital folds become in females?

Ventral aspect of penis:

What does the Urogenital folds become in males?

Labia majora:

What does the Labioscrotal swellings become in females?

Scrotum:

What does the Labioscrotal swellings become in males?

Tanner scale:

What scale is used for physical development as prepubescent children transition into adolescence, and then adulthood?

James Tanner:

Who quantified the Tanner scale?

Size of the breast, length of the penis, volume of the testes, and growth of pubic hair:

What physical characteristics does the Tanner scale measure?

Testicular volume less than 1.5 ml:

What is the testicular volume for Tanner stage I (Genitals – Male)?

No glandular tissue: areola follows the skin contours of the chest (prepubertal):

What is the characteristic of Tanner I (Breast – Female)?

No pubic hair at all (prepubertal):

What is the characteristic of Tanner I (Pubic Hair – both male and female)?

Duplication of the uterus:

What is the result of lack of fusion of the paramesonephric duct?

Hypospadias, Epispadias, Micropenis, Bifid or double penis:

What are some defects of the male genitalia?