03-01 - phenotypic sex stuff I skipped

Question 1

(Phenotypic Sex)

(Sexual Differentiation of the Reproductive Tracts)

READ THIS

To achieve either male or female gonads the starting point was a single indifferent structure (albeit with cortical and medullary regions) which then differentiated as either male (testicle) or female (ovary). The strategy for developing the male and female duct systems is the opposite. All embryos start with the rudiments of both male and female systems, one of which will regress while the other develops under the influence of the now sexually differentiated gonads.

Question 2

(Phenotypic Sex)

(Sexual Differentiation of the Reproductive Tracts)

1. In the early, sexually undifferentiated embryo, what ducts appear first? as what?
2. The rudiemntary female ducts (Mulerian or paramesonephric ducts) only develop after what is visible?

where do they develop?

Answer 2

1. the rudimentary male ducts (Wolffian or mesonephric ducts); the excretory ducts of the mesonephros
2. the early indifferent gonad

adjacent to the Wolffian ducts, starting near the gonad and developing caudally, using the Wolffian ducts as a guide (hence paramesoneprhic)

(there is a picture on pg14 that might be helpful to look at)

Question 3

(Differentiation of the male reproductve tract)

1. The efferent ducts that connect the rete testes to the epidiymis arise from what?
2. During the develpoment from the Wolffian duct the epididymis become what? in preparation for what?
3. Urogenital folds elongate and fuse to form what?

genital swelling fuse to form what?

genital tubercle develops into what?

Answer 3

1. residual mesonephric tubules
2. extremely convoluted; in preparation for its task in the mature animal of sperm maturation and storage
3. the penile shaft

scrotum

glans penis

Question 4

(Differentiation of the male reproductive tract)

1. Positive effects of the reproductive tract male sex differentiation (vas deferens, epidiymis, seminal vesicles, penis) are dependent on what?
2. Negative aspects of male differentiatoin (regression of Mullerian duct) are controlled by what?

Answer 4

1. androgens
2. MIS (AMH)

Question 5

(Origin of mature structures)

(I’ll give you embyronic sturcture - you give me what it turns into… male first,,,, the female)

1. indifferent gonad
2. Wolffian duct (mesonephric duct)
3. Mullerian duct (paramesonephric duct)

Answer 5

1. testicle

ovary

2. epididymis, vas deferens, seminal vesicles

regresses

3. regresses

oviduct, uterus, cranial vagina

Question 6

(Origin of mature structures)

(I’ll give you embyronic sturcture - you give me what it turns into… male first,,,, the female)

1. urogential sinus
2. genital tubercle
3. urogential folds
4. genital swellings

Answer 6

1. prostate, prostatic urethra, bulbourethra

urethra, distal vagina

2. glans penis

clitoris

3. penile shaft

labia minora

4. scrotum

labia majora (regress in domestic)