Exam Two - high yield for Funk's Embryo

Question 1

The genital ridge forms the ________

Answer 1

gonad (testis or ovary)

Question 2

Both the urinary and internal reproductive organs develop primarily from ___________

Answer 2

intermediate mesoderm

Question 3

The mesonephric duct goes on to form the ___________

Answer 3

male internal reproductive organs (Wolffian duct) (not the testes)

Question 4

The paramesonephric duct forms the _____________

Answer 4

female internal reproductive viscera (Mullerian duct) (everything except for the ovaries)

Question 5

Genotype of gender is determined immediately at ________

Answer 5

fertilization

Question 6

What induces the formation of the testes?

Answer 6

The gene product of the SRY gene (found on Y chromosome)… Testis-Determining Factor (TDF)… this masculinizes the indifferent genital system

Question 7

“So, the genes control the gonad, and after that the _______ controls the external and internal genitalia”

Answer 7

gonad

Question 8

What happens if the primordial germ cells (PGC’s) fail to migrate to the genital ridges around weeks 4 –> 6?

Answer 8

The gonads will not form

Question 9

What is the gubernaculum?

Answer 9

It is a thick ligament that attaches the caudal pole of the testes to the anterior body wall (forms future site of deep inguinal ring)

Question 10

What hormone controls descent of the testes from the abdomen to the scrotum?

Answer 10

Testosterone

Question 11

Describe the processes vaginalis:

Answer 11

It is an evagination of peritoneum that passes through the abdominal wall lateral to the site of attachment of the gubernaculum

Question 12

Role of antimullerian hormone (AMH)?

Answer 12

AMH produced by Sertoli cells will inhibit paramesonephric ducts from developing into female genital ducts

Question 13

*What is the cause of the congenital anomaly hypospadia?

Answer 13

*The urethral folds fail to fuse on the ventral surface of the penis

Question 14

What causes epispadia?

Answer 14

This is not fully understood; the urethral opening occurs on the dorsum of the penis

Question 15

Cause of indirect hernia?

Answer 15

Results from a failure of processus vaginalis to close around deep inguinal ring

Question 16

What is the cause of hydrocele?

Answer 16

Excessive production of serous fluid within tunica vaginalis; congenital hydroceles are common… resolve on their own; hydroceles in adults are usually due to inflammation

Question 17

Cause of cryptorchidism (“hidden testicle)?

Answer 17

Failure of testes to descend into testes during development

***very high risk factor for testicular CA

Question 18

What truly leads to the differentiation of the female “body plan”?

Answer 18

The absence of AMH (female internal/external reproductive viscera form in the ABSENCE of hormones… “the default body plan”… a functional ovary is not require for the development of the female repro tract)

Question 19

If there is no testosterone, the mesonephric duct ________

Answer 19

regresses

Question 20

What remnants of the mesonephric duct can form cysts in females?

Answer 20

The structures epoophoron, paroophoron, and Gartner’s duct (cause of pelvic pain in females)

Question 21

What structure elongates to form the clitoris?

Answer 21

The genital tubercle

Question 22

Cause of uterus arcuatus?

Answer 22

“slight” lack of fusion of two paramesonephric ducts

Question 23

Cause of uterus bicornis bicollis?

Answer 23

“more of a” lack of fusion of paramesonephric ducts (two uterine horns, two necks of cervices)

Question 24

Cause of uterus didelphys (w/ double vagina)?

Answer 24

“everything is doubled/paired” … COMPLETE lack of fusion

Question 25

Cause of uterus bicornis unicollis (1 rudimentary horn)?

Answer 25

one paramesonephric duct fails to make contact with the other (its distal part regresses)

Question 26

Cause of uterus unicornis (unicornuate uterus)?

Answer 26

one paramesonephric duct regresses

Question 27

Klinefelter Syndrome (male)

Answer 27

47, XXY; male

Caused by nondisjunction

Testes form, but are infertile (aspermatogenesis) due to low testosterone levels

Impaired sexual maturation (problems @ puberty)

Gynecomastia (due to high levels of estrogen)

Question 28

*Turner Syndrome (female)

Answer 28

45, XO; female

Cause: Nondisjunction

Results in: Gonadal dysgenesis; streak gonads (genital ridge persists)

Because ovaries are not required for internal and external genitalia formation: female external and internal genitalia (except ovaries) are normal

Lack of secondary sex trait development at puberty (because no ovaries = no estrogen)

Also present: Short-stature, broad chest, short neck; lymphedema of hands and feet; amenorrhea

Question 29

*Swyer Syndrome

Answer 29

46, XY; genetically male, phenotypically female

Cause: Point mutation of SRY gene; defective TDF protein

Results in: Gonadal dysgenesis; streak gonads

Because ovaries are not required for internal and external genitalia formation: female external and internal genitalia (except ovaries) are normal

Lack of secondary sex trait development at puberty (because no ovaries = no estrogen)

Also present: Amenorrhea

Question 30

“True” Hermaphroditism

Answer 30

Most have the 46, XX genotype

Cause: not fully understood; likely translocated Y chromosome

Ovotestes – ovarian and testis tissue found in same gonad

Internal genitalia are most often female

Ambiguous external genitalia

Very rare

Question 31

Female Pseudohermaphroditism

Answer 31

46, XX

Cause: Congenital adrenal hyperplasia

Ovaries form (due to absence of TDF; 2 normal X chromosomes)

Internal reproductive organs usually female

Masculinization of external genitalia (due to timing of increased adrogens from adrenal gland)

Question 32

*Male Pseudohermaphroditism

Answer 32

46, XY

Testes form (normal SRY gene; normal TDF)

Cause: Insufficient androgen production and AMH from testes (hypogonadism)

External and internal genitalia female (due to absence of testosterone and AMH)

Question 33

Androgen Insensitivity Syndrome

Answer 33

46, XY

Testes form due to normal functioning Y chromosome

AMH and testosterone production is normal (testes are normal)

Cause: Lack of androgen receptors expression on reproductive tissues (tissues are not responsive to testosterone)

Mesonephric duct degenerates (due to testosterone insensitivity); no male internal reproductive viscera.

Paramesonephric ducts degenerate (due to presence of AMH); no female internal reproductive viscera

Female external genitalia (because these will form in the absence of hormonal input); Vagina is short and blind-ending (no uterus)