Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/39

Click to flip

39 Cards in this Set

  • Front
  • Back
how do the gonads first appear?
genital ridges: a pair of longitudinal ridges that bulge into the coelom.
what types of mesoderm are the genital ridges?
intermediate mesoderm and splanchnic mesoderm.
where do primordial germ cells originate?
the yolk sac
where do the primordial germ cells migrate and populate?
genital ridges
how do the primitive sex cords form?
epithelium of the genital ridge proliferates and invades the underlying mesenchyme.
what does "indifferent gonad" mean?
the male and female gonads initially look identical
describe testis development from sex cords to production of testosterone
primitive sex cords form testis cords. testis cords cavitate to form the seminiferous tubules and rete testis. Interstitial cells (of Leydig) form from intermediate mesoderml, and produce testosterone by week 8.
what type of mesoderm do interstitial cells derive from?
intermediate mesoderm
what forms the vas deferens and epididymis?
mesonephric (Wolffian) duct
what form the efferent ductules of the testis?
mesonephric tubules
how do the prostate and bulbourethral glands form?
expand from the endoderm of the urogenital sinus.
how do the seminal vesicles form?
branch from the mesonephric ducts
describe ovary development until formation of follicular cells.
-primitive sex cords turn into irregular cell clusters.
-epithelium gives rise to a second generation of sex cords: the cortical cords.
-cortical cords split into isolated cell clusters that surround the primordial germ cells and form follicular cells.
what happens to the mesonephric ducts and tubules in females?
they largely degenerate.
what are the 3 remnants of the mesonephric ducts and tubules?
epoophoron, paroophoron, and gartner's cysts.
does the paramesonephric (Mullerian) duct initially form in both males and females?
yes
where does the paramesonephric (Mullerian) duct form?
ventrolateral surface of the urogenital ridge
describe the Mullerian ducts cranially and caudally
cranially they are open, caudally they run to the midline, fuse, and project into the dorsal wall of the UG sinus.
what happens to the paramesonephric (Mullerian) ducts in the female?
cranially they become the uterine tubes. Caudally they fuse to form the uterovaginal canal.
what forms at the junction of the paramesonephric ducts in the female?
paramesonephric tubercle
what happens to the paramesonephric tubercle?
extends as a solid vaginal plate towards the uterovaginal canal. the plate cavitates to form the vaginal lumen.
what happens to the paramesonephric ducts in the male?
testes secrete anti-Mullerian hormone, which causes the degeneration of the ducts.
what remains of the paramesonephric ducts in the male?
at the cranial end: appendix testes.
at the caudal end: prostatic utricle.
describe development of the indifferent stage of the external genitalia
mesenchyme lateral to the cloaca proliferates to form the cloacal folds. the folds unite cranially to become the genital tubercle. caudally the folds subdivide to form the urogenital folds and the anal folds. genital swellings form lateral to the urethral folds.
how is the urethral fold formed?
the urogenital membrane breaks down to form the urethral fold.
what is development of the external genitalia dependent on?
testosterone
describe development of male external genitalia from end of indifferent stage to urethral fold closing.
the genital tubercle elongates and pulls the urethral plate and folds with it. the urethral folds close over the urethral plate, thereby enclosing the penile urethra.
describe development at tip of the penis
ectodermal cells from tip invaginate and form a short ectodermal cord. the chord meets with the spongy (penile) urethra, and cavitates to complete the penile urethra.
what are hypospadias?
abnormal position of penile urethra.
what 2 things can cause a hypospadia?
1. failure of canalization of ectodermal cord.
2. failure of fusion of the urethral folds.
describe how scrotum forms from indifferent stage of external genitalia.
scrotal swellings move caudally and fuse. the two halves remain separate internally.
where does the gubernaculum grow into?
grows into the scrotal swellings.
what happens to the parietal peritoneum during the descent of the testes? what does it form?
it forms an evagination into the ventral abdominal wall: vaginal process.
what is cryptorchidism?
failure of testes to descend.
what does the vaginal process eventually form?
forms the scrotal cavity with parietal and visceral layers of serosa.
what can a patent vaginal process cause?
partial or complete herniation of the intestines into the spermatic chord or scrotum
what is a hydrocele?
coelomic fluid can remain trapped in scrotum after vaginal process obliterates.
describe development of external genitalia in females after indifferent stage.
genital tubercle elongates slightly to form clitoris. urethral folds don't fuse, but form the labia minora. genital swellings enlarge and form the labia majora.
what largely causes uterine defects?
failed fusion of the paramesonephric ducts.