Repro - 1-28 - Normal/abn Female Sexual Diff And Devo

Front 1

Where do male primordial germ cells go?

Back 1

Medullary region for testicular lines.

Front 2

Where do female primordial germ cells go?

Back 2

Cortical region for ovarian lines.

Front 3

Two main diff btwn male and female diff

Back 3

For male, testicular determinant genes must be present and functional to direct primordial germ cells in the medullary region for the formation of testes.
(overy det genes need not be present for women)

The developing testis must be a function endocrine gland during differentiation. It must produce hormones important for differentiation of the internal ductal system as well as external genitalia.
Ovary is not an active endocrine organ during devo

Front 4

Two genes other than SRY important for testicular differentiation

Back 4

SF-1 and SOX-9

Front 5

Where is SRY located?

Back 5

short arm of Y chromosome.

Front 6

Sertoli cells

Back 6

At base of seminiferous tubules (which envelops primordial germ cells).

They are guardians of the germ cell and produce mullerian inhibiting substance which causes regression of mullerian system in males.

Front 7

At end organ, what happens to testosterone?

Back 7

5-alpha reduced to dihydrotestosterone (which completes external genital devo in the male.

Front 8

What allows for wolfian completion?

Back 8

testosterone

Front 9

Laterality of MIS and testosterone

Back 9

only acts on the same side of the body.

Left MIS - regression of left mullerian system.

Lest testosterone - complteion of wolffian system on left side.

Front 10

Replenishment of germ cells in the female

Back 10

Only during fetal time period.

Arrest at meiosis I at the prophase stage. This requires ovarian determinant genes present on both arms of the X-chrom. Also peptide hormones such as cAMP, MIS (yes, that's what it says).

Front 11

What surrounds female primordial germ cells?

Back 11

primitive mantel of granulosa cells.

Front 12

In male, once primordial germ cells get to the undiff genital ridge, what needs to have to get male sexual diff?

Back 12

1. Testic determinant genes expressed
2. Bilat gonadal elab of MIS
3. bilat gonadal prod of testosterone
4. Test conv at end organ to DHT
5. Function receptors for proteins like LH, MIS, androgens, etc.

Front 13

In female, once primordial germ cells get to the undiff genital ridge, what needs to have to get female sexual diff?

Back 13

expression of ovarian determinant genes at a later time of devo.

Front 14

Classes of abnormalities of normal sexual differentiation

Back 14

Deletion syndromes

46, XY

Classic ovotesticular disorders of sexual diff (true hermaphrodites)

46, XX androgenized indiv.

Front 15

Pseudohermaphrodite

Back 15

external genitalia contradicts karyotype. (e.g. 46, XY indiv who is undermasculinized)

Front 16

Hermaphrodite

Back 16

Indiv has ovarian and testic tissue.

Histology must show follicles and seminiferous tubules.

Front 17

Deletion syndromes

Back 17

45,X and 45,X/46,XY

Caused by deletion of ovarian determinant genes on X. Results in loss of germ cells.

Almost all pts have Turner syndrome.

Front 18

Phenotypic spectrum of deletion syndromes

Back 18

Classic Turner phenotype of genital ambiguity to normal male with normal spermatogenesis.

Front 19

What is internal ductal system and devo of the external genitalia dependent on?

Back 19

gonads.

Front 20

46,XY category

Back 20

syndromes where defects have been found at each step in male sexual diff.

Usually due to gene mutations.

Examples are defects in SRY, MIS or its receptor, Beta-LH or LH or its receptor, enzyme genes in steroidogenic pathway, androgen receptor gene.

Front 21

True hermaphrodites category

Back 21

Usually 46, XX. But can be 46,XX/46,XY (chimeras due to fusion - Ovary on one side and testis on opposite side.)

46 XX - will have ovotestis on one or both sides.

Front 22

46,XX androgenized individuals.

Back 22

Testicular genes are present because of translocation.

Usually normal phenotypic males who are infertile and azoospermatic.

Front 23

Most common cause of 46,XX disorder of sexual development

Back 23

Congenital adrenal hyperplasia

Front 24

Most common form of CAH

Back 24

21-hydroxylase deficiency - can't make cortisol so POMC gets no feedback and makes tons of precursor which is shunted to make androgens.

(this doesn't affect male genitalia for male fetuses)

Front 25

Presence of single or bilat descended testis rules out...

Back 25

congenital adrenal hyperplasia

Front 26

Females with CAH - presentation at birth

Back 26

external genitalia with varying degrees of masculinzation. But they also have intra-abd ovaries so no descended gonads.

Front 27

Male at birth with CAH...

Back 27

will not be IDed as abnormal.

Front 28

Other forms of CAH

Back 28

11-beta hydroxylase deficiency. which can then result in three beta-ol-dehydrogenase deficiency (CV collapse occurs very quickly)

Front 29

Aromatase deficiency

Back 29

results in androgenization of the fetus with high levels of placental androgens.

Will have acne and hirsutism.

Front 30

Can high levels of endogenously produced testos masculinize a female fetus?

Back 30

rarely

But a DHT tumor (which can't be aromatized) will.

Front 31

Misc abnormalities

Back 31

13p-
Intrauterine viral infections
Females with congen absence of uterus and vagina.
Men with congen bilat absence of vas def