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20 Cards in this Set
- Front
- Back
what are the 3 levels of hierarchal development that determine the phenotypic sex of an individual (and in what order do they occur)
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1. genetic sex (chromosomal)
2. gonadal sex 3. somatic sex (phenotypic) |
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what determines genetic sex
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the haplotype of the sex chromosome of the fertilizing sperm cell
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what is gonadal sex
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the sex specific development of the gonads is determined by the genetic sex
in the absence of Y chromosome, ovary is formed in presence of Y, induce gonadal ridge formation of a testicle this formation implies not only morphologic formation but also endorine fxn the SRY region of Y chromosome promotes differentiation fo sertolicellls and interstitial cells sertoli cells produce anti-mullerian hormone (MIH) leydig cells produce testosterone |
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what cells produce anti-mullerian hormone
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sertoli cells
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what do leydig cells produce
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testosterone
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somatic sex is dependent on
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the presence of absence of anti mullerian hormone and testosterone.
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what happens in the absence of testicular hormones
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the female repro tract arises
- wolffian ducts regress - mullerian ducts grow and differentiate |
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what happens in the presence of anti-mullerian factor
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the mullerian ducts regress
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what happens in the presence of testosterone (as far as somatic sex is concerned)
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the wolffian ducts differentiate
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hermaphrodite vs pseudohermaphrodite
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herm
- all or part of the gonadal organs of both sexes - one testis and one ovary - one or both gonads are ovotestes - part of all of the genital organs of both sexes are present - ovary, testis, uterus, and phallus are all present pseudo herm - the gonads are of one sex and there is at least partial phenotypic expression (tubular genitalia) of the opposite sex (common in goats/ pigs, rare in horses/ dogs/ cattle |
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mixed gonadal dysgenesis
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partial formation of testis or ovary w/in a gonadal streak tissue or regional testicular formation w/in an ovary
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gonadal dysgenesis
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primitive gonadal streaks are present but there is not definitive differentiation of either gonadal type.
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Micropically you see immature ovarian stroma w/o oocyte or spermatogonia presence.
What is your dx? |
gonadal dysgenesis
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You find regional testicular formation within an testicle.
What is your dx? |
mixed gonadal dysgenesis
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what is the normal process resulting in sex reversal
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sxr mutation
usually due to translocation of the testis-determining region of the Y chromosome to the X chromosome genetic sex is XX^sxr (female) b/c the genetic info is translated from the X^sxr chromosome, the gonadal, somatic, and phenotypic sex is male. |
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what is testicular feminization
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tfm mutation (androgen insensitivity)
x linked androgen receptor defect genetic sex is X^tfmY (male) gonadal formation is testicular (male) & during fetal development, the testis produces testosterone and AMF, but test sens tissues don't respond. so individuals have testicles, regression of wolffian ducts, regression of mullerian ducts, but external female phenotype with a blind end vaginal vault. |
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a horse has testicles, regression of wolffian ducts, regression of mullerian ducts, but external female phenotype with a blind end vaginal vault.
What is your dx? |
Tfm mutation (testicular feminization/ androgen insensitivity)
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freemartinism
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primarily occurs in cattle
female and male twins share placental circulation hormones (MIH and test) or cells circulate from male calf to female calf. female calf will have XX genetic sex, but gonadally and somatically may exhibit a range of masculization mixed testicular/ovarian formation, gonadal stunting, vesicular gland formation, hypoplastic tubular strx, clitoral hypertrophy, or vaginal hypoplasia |
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you have a goat with vulva, vagina, cervix, uterus, and testicles.
What is your dx? |
pseudo-hermaphrodite
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You see cotyledonary necrosis (multiple white foci) in a sheep abortion.
What is your dx? |
Toxoplasma placentitis
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