Flashcards in L47: Urogenital Development Deck (58):
The Proliferation of the intermediate mesoderm (IM) generates the __________.
Nephorogenesis involves the successive appearance of 3 kidney primordia. What are they called? (Top to bottom when fetus is facing left)
The ______ derives from the mesonephric duct, while the kidney derives from the caudal end of the nephrogenic cord
The collecting system of the urinary system (kidney) derives from what?
When the kidney is being developed, what structure is part of the external region?
When kidney is being developed, what structures are part of the internal region?
Renal pelvis, major calyx, minor calyx, collecting tubes
The excretoru system derives from the ________?
Changes in the body shape makes the kidney take an ____ position
There is disappearance of arteries of kidney during formation except for the __________
Accessory renal artery
The cloaca (hindgut region) divides to form the primitive _______, from which the _____ and ___________ derive
Urogenital sinus; bladder & pelvic urethra
While the absorption of the mesonephric ducts makes the ureters join the bladder wall, the kidneys äscent" induces the develpment of the ___________
The genital system derives from the ________ and adjacent ducts
An embryo is bipotent and can develop to male or female. Mesonephros gives rise to 3 things- what are they?
- Mesonephic duct: gives rise to male genital ducts, requires androgens to develop, degenerates in females in response to low androgen levels
- Genital ridge: gives rise to the testes or ovaries (source of androgens and estrogens)
- Paramesonephric (Mullerian) duct: gives rise to female genital ducts, does not require hormones to develop, degenerates in males in response to Mullerian inhibiting substance (MIS)
Regardless of the genetic sex, the _____ have an initial indifferent stage
The primordial germ cells (PGCs) are close in proximity/ associated with what two things?
- Proliferating coelomic epithelium
- Primitive sex cords
Primordial germ cells give rise to either what or what?
Spermatogonia (male) or Oogonia (female)
Priminitive sex cords form what eventually?
Seminiferous cords, which gather together in loops
Tunica albuginea formed by thickening of coelmic epithelium that is losing connection with ___________
In male embryos the indifferent gonad differentiate into testes under the ____________ gene of the Y chromosome
influence of SRY
In the female embryo, the absence of the SRY gene results in dissociation of the primitve sex cords and differentiation of the gonad into _____
The medullary cords in the female embryo are going to _____
Degenerate and fill with vessels, tissues, etc
In ovary, in most mammal (cow, sow), the central location will disappear. In the mare, it will be the opposite the region from the primitive that would disappear will be the __________
Only one region of primitive cord survives- it will get divided and germ cells get enclosed by coelemic cells that give rise to ________
Primordial follicle derives from the _______
In primitive cords, males give rise to ______ cells, females _____ cells
The _______ derive from the mesonephric tubules, while the epididymis, ductus deferens, ampullas and vesicular glands derive from the ____________.
Efferent ducts; mesonephric duct
What is another name for the paramesonephric duct remnant?
The uterine tubes, uterus and cranial region of the vagina derive from the ____________ duct, while ___________________ & _____ derive from the urogenital sinus
Paramesonephric duct; caudal region of the vagina and vestibule
The dengenerating proxmial mesonephric tubules is called? What about the distal ""?
The ________ derives from mesenchymal cells that proliferate and surround the cloacal membrane
The Urogenital system derives frrom what two things?
1. Intermediate mesoderm (IM)
2. Mesodermal coelomic epithelium
Mesenchymal cells migrate around the cloacal membrane and form the __________. These fuse to form the __________. Dorsally, as the cloca dives, the folds form the ________ folds and _______ fold.
Urogenital folds and anal folds
Mesenchymal cells also forma second pair of elevations- the ____________
In males, induced by androgens, the _______ gives rise to the erticle tissue and tunica albuginea of the penis, and the urogenital folds to the caudal region of the penile urethra
The cranial region of the urethra derive from the _______ cells at the tip of the penis
Genital swellings give rise to the ____
The genital tuercle in males under androgen influence elongates to form the _________
The urogenital folds of the male folds forward so that they form the ________________
Lateral walls of the urethral groove
The urogenital folds cover the urethral plate to form the ______
Ectodermal cells at the tip of the ____ form the __________________
Most cranial region of the urethra
Genital swellings, which are now the scrotal swellings, move cranially and each amkes up half of the ______ and are separated by the ________
If females, induced by estrogens, the genital tubercle gives rise to the _____, while the urogenital folds and genital swellings to the ______. the _____ derives from the urogenital sinus
In the female, the urogenital folds remain separated (by the urogenital groove) and form the ______ of the vulva
The genital swellings of the female as well as urogenital folds give rise to the labia ___ and ____
Minora and majora
The caudal area of the urogenital sinus (and urogenital groove) gives rise to the _____
Ovaries produce _____
Testes produce ____ and ____________
Androgens and Insulin-like peptide 3 (INSL3)
Testis descent is necessary for ______ but not for ________. However, proper steroidogenesis is necessary for testis _____
Spermatogenesis but not steroidogenesis
What are the two type of testes?
1. Abdominal testes
2. Scrotal testes
In testicond species, both ovaries and testes descend ______
Testis descent occurs in what two phases and by what?*
Caused by gubernaculum
What is a gubernaculum?
A band of mesenchymal tissue, extends from the caudal pole to the testis to the genital swellings
What does the intra-abdominal phase consists of? What hormone does it depend more on?
- Reduction of size of gubernaculum
What does the extra-abdominal phase consist of? What hormon does it depend more on?
- Increase size of gubernaculum
- Reduction of size of gubernaculum
Time of descent for these species: horse, cattle, dog, pig
Horse: during 10-11th month gestation
Cattle: During 4th month gestation
Dog: 3-25 days postnatally
Pig: during 3rd month of gestation
What does the lack of androgens and INSL3 by the testes during fetal life result in?
Presence of functional glands, masculine behavior and phenotype in animals without scrotal testes and clinical history of castration indicates a cryptorchid male in which the cause involved is a mechanical defect due to what two things?**
- Deficient formation or action of the gubernaculum
- Lower levels of androgens or INSL3