L47: Urogenital Development

Question 1

The Proliferation of the intermediate mesoderm (IM) generates the __________.

Answer 1

Urogenital plate

Question 2

Nephorogenesis involves the successive appearance of 3 kidney primordia. What are they called? (Top to bottom when fetus is facing left)

Answer 2

1. Pronephros
2. Mesonephros
3. Metanephros

Question 3

The ______ derives from the mesonephric duct, while the kidney derives from the caudal end of the nephrogenic cord

Answer 3

Ureter

Question 4

The collecting system of the urinary system (kidney) derives from what?

Answer 4

Uretic bud

Question 5

When the kidney is being developed, what structure is part of the external region?

Answer 5

Ureter

Question 6

When kidney is being developed, what structures are part of the internal region?

Answer 6

Renal pelvis, major calyx, minor calyx, collecting tubes

Question 7

The excretoru system derives from the ________?

Answer 7

Metanephric bastema

Question 8

Changes in the body shape makes the kidney take an ____ position

Answer 8

Abdominal

Question 9

There is disappearance of arteries of kidney during formation except for the __________

Answer 9

Accessory renal artery

Question 10

The cloaca (hindgut region) divides to form the primitive _______, from which the _____ and ___________ derive

Answer 10

Urogenital sinus; bladder & pelvic urethra

Question 11

While the absorption of the mesonephric ducts makes the ureters join the bladder wall, the kidneys äscent” induces the develpment of the ___________

Answer 11

Vesical trigone

Question 12

The genital system derives from the ________ and adjacent ducts

Answer 12

Mesonephros

Question 13

An embryo is bipotent and can develop to male or female. Mesonephros gives rise to 3 things- what are they?

Answer 13

• 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)

Question 14

Regardless of the genetic sex, the _____ have an initial indifferent stage

Answer 14

gonads

Question 15

The primordial germ cells (PGCs) are close in proximity/ associated with what two things?

Answer 15

• Proliferating coelomic epithelium

- Primitive sex cords

Question 16

Primordial germ cells give rise to either what or what?

Answer 16

Spermatogonia (male) or Oogonia (female)

Question 17

Priminitive sex cords form what eventually?

Answer 17

Seminiferous cords, which gather together in loops

Question 18

Tunica albuginea formed by thickening of coelmic epithelium that is losing connection with ___________

Answer 18

Seminiferous cords

Question 19

In male embryos the indifferent gonad differentiate into testes under the ____________ gene of the Y chromosome

Answer 19

influence of SRY

Question 20

In the female embryo, the absence of the SRY gene results in dissociation of the primitve sex cords and differentiation of the gonad into _____

Answer 20

ovaries

Question 21

The medullary cords in the female embryo are going to _____

Answer 21

Degenerate and fill with vessels, tissues, etc

Question 22

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 __________

Answer 22

Periphery elements

Question 23

Only one region of primitive cord survives- it will get divided and germ cells get enclosed by coelemic cells that give rise to ________

Answer 23

Granulosa cells

Question 24

Primordial follicle derives from the _______

Answer 24

Seminiferous cords

Question 25

In primitive cords, males give rise to ______ cells, females _____ cells

Answer 25

Leydig; theca

Question 26

The _______ derive from the mesonephric tubules, while the epididymis, ductus deferens, ampullas and vesicular glands derive from the ____________.

Answer 26

Efferent ducts; mesonephric duct

Question 27

What is another name for the paramesonephric duct remnant?

Answer 27

Male uterus

Question 28

The uterine tubes, uterus and cranial region of the vagina derive from the ____________ duct, while ___________________ & _____ derive from the urogenital sinus

Answer 28

Paramesonephric duct; caudal region of the vagina and vestibule

Question 29

The dengenerating proxmial mesonephric tubules is called? What about the distal ""?

Answer 29

Epoophorom; paroophorom

Question 30

The ________ derives from mesenchymal cells that proliferate and surround the cloacal membrane

Answer 30

external genitalia

Question 31

The Urogenital system derives frrom what two things?

Answer 31

1. Intermediate mesoderm (IM) | 2. Mesodermal coelomic epithelium

Question 32

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.

Answer 32

Cloacal folds Genital tubercle Urogenital folds and anal folds

Question 33

Mesenchymal cells also forma second pair of elevations- the ____________

Answer 33

Genital swellings

Question 34

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

Answer 34

Genital tubercle

Question 35

The cranial region of the urethra derive from the _______ cells at the tip of the penis

Answer 35

Ectodermal

Question 36

Genital swellings give rise to the ____

Answer 36

Scrotum

Question 37

The genital tuercle in males under androgen influence elongates to form the _________

Answer 37

Phallus

Question 38

The urogenital folds of the male folds forward so that they form the ________________

Answer 38

Lateral walls of the urethral groove

Question 39

The urogenital folds cover the urethral plate to form the ______

Answer 39

Penile urethra

Question 40

Ectodermal cells at the tip of the ____ form the __________________

Answer 40

glands | Most cranial region of the urethra

Question 41

Genital swellings, which are now the scrotal swellings, move cranially and each amkes up half of the ______ and are separated by the ________

Answer 41

Scrotum | Scrotal septum

Question 42

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

Answer 42

Clitoris Vulva Vestibule

Question 43

In the female, the urogenital folds remain separated (by the urogenital groove) and form the ______ of the vulva

Answer 43

Labia

Question 44

The genital swellings of the female as well as urogenital folds give rise to the labia ___ and ____

Answer 44

Minora and majora

Question 45

The caudal area of the urogenital sinus (and urogenital groove) gives rise to the _____

Answer 45

Vestible

Question 46

Ovaries produce _____

Answer 46

Estrogens

Question 47

Testes produce ____ and ____________

Answer 47

Androgens and Insulin-like peptide 3 (INSL3)

Question 48

Testis descent is necessary for ______ but not for ________. However, proper steroidogenesis is necessary for testis _____

Answer 48

Spermatogenesis but not steroidogenesis | Testis descent

Question 49

What are the two type of testes?

Answer 49

1. Abdominal testes | 2. Scrotal testes

Question 50

In testicond species, both ovaries and testes descend ______

Answer 50

partially

Question 51

Testis descent occurs in what two phases and by what?*

Answer 51

1. Abdominal 2. Extra-abdominal Caused by gubernaculum

Question 52

What is a gubernaculum?

Answer 52

A band of mesenchymal tissue, extends from the caudal pole to the testis to the genital swellings

Question 53

What does the intra-abdominal phase consists of? What hormone does it depend more on?

Answer 53

- Reduction of size of gubernaculum | INSL3

Question 54

What does the extra-abdominal phase consist of? What hormon does it depend more on?

Answer 54

- Increase size of gubernaculum - Reduction of size of gubernaculum Androgens

Question 55

Time of descent for these species: horse, cattle, dog, pig

Answer 55

Horse: during 10-11th month gestation Cattle: During 4th month gestation Dog: 3-25 days postnatally Pig: during 3rd month of gestation

Question 56

What does the lack of androgens and INSL3 by the testes during fetal life result in?

Answer 56

Cryptorchid male

Question 57

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?**

Answer 57

- Deficient formation or action of the gubernaculum | - Lower levels of androgens or INSL3

Question 58

Absence of puberty and male phenotype in animals without scrotal testes and clinical history of castration indicate a cryptorchid male in which the cause involved is a lack of androgen and/or INSL3 secretion during fetal life due to what 2 things?**

Answer 58

- Severe abnormalities in Leydig cells | - Environmental factors severely affecting Leydig cells (eg endocrine disruptors)