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Terms in this set (51)
Development of both male and female internal genitalia, but ONLY male external genitalia.
No sertoli cells -or- lack of Mullerian Inhibitory Factor
Male internal genitalia, ambiguous external genitalia until puberty
5α reductase deficiency
What do sertoli cells secrete?
Mullerian Inhibitory Factor
Inhibin → ↓FSH
Homolog of female granulosa cells
What do leydig cells secrete?
Testerosterone in the presence of LH
↑LH → ↑Testosterone
Homolog of female theca interna cells
Which cells are sensitive to temperature? Leydig or Sertoli?
Sertoli cells are sensitive to temperature... Leydig cells are insensitive (testosterone production is unaffected by temperature)
↓ Sperm production & ↓ Inhibin with ↑ Temp
↑ Temp in Varicocele & Cryptorchidism
Cholesterol → Androgens
Increased by LH in the theca interna cells
Androgens → Estrogens
Increased by FSH in the granulosa cells
Side-effects of estrogen on cholesterol synthesis.
Facilitates the synthesis of Cholesterol by ↑ HMG-CoA Reductase → *Gall Stones*
Oral Contraceptive Pills
*Pregnancy* also causes *hypomotility* of the gallbladder favoring stone formation.
↓ by Progesterone → Smooth muscle relaxation
↑ by Estrogen
The fall in this hormone after delivery disinhibits prolactin and results in lactation.
Progesterone and Estrogen
What hormone is indicative of ovulation?
Means ovulation has occurred...
Which hormones are responsible for ovulation?
Estrogen → LH Surge → Ovulation (rupture of the follicles)
↑ Temperature induces Progesterone
↓ fertility is caused by a decrease in what hormone?
PROgesterone is PRO gestation
Menstrual cycle hormones
↑ Estrogen → LH surge → Ovulation → Progesterone (from the corpus luteum) → Progesterone levels fall if fertilization does not occurs → Menstruation (via apoptosis of endometrial cells)
From birth → Ovulation, oocytes are arrested in what stage?
Prophase I of Meiosis I
From ovulation → fertilization, oocytes are arrested in what stage?
Metaphase II of Meiosis II
What hormone rises throughout pregnancy and is proportional to fetal mass?
Human Placental Lactogen
Secretion of progesterone after fertilization has occurred (pregnancy) occurs in what structure?
Corpus luteum secretes 17-Progesterone until *week 10*, then the placenta secretes progesterone for the remainder of pregnancy.
What increases milk letdown?
Suckling → ↑ Oxytocin & Prolactin
Does prolactin ↑ or ↓ reproductivity?
Prolactin inhibits ovulation in females and spermatogenesis in males by inhibiting GnRH synthesis and release.
↑ Prolactin = ↓ Libido
IF infants are exclusively breastfed, what nutrient must the have supplemented?
Breastfeeding ↓ maternal risk of breast and ovarian cancer.
What does hCG act like?
hCG acts like LH = ↑ Testosterone = ↑ Conversion to Estradiol = Gynecomastia
Secreted by Syncytiotrophoblasts (fetal) of the placenta
What hormone is used to detect pregnancy?
hCG.... Appears early in the urine. 2 weeks for home pregnancy test (detects the β subunit) , 1 week for OBGYN
hCG shares an identical subunit with what hormones?
FSH, LH, and TSH
The β subunit is unique
What might ↑ hCG levels in pregnancy indicate?
What might ↓ hCG levels in pregnancy indicate?
Which hormone is specific for menopause?
Loss of negative feedback on FSH due to ↓ Estrogen
Hormone changes seen in menopause?
↓ Estrogen, ↑↑ FSH, ↑LH (no surge), ↑GnRH
What are the androgens?
Androstenedione (adrenal glands)
Potency: DHT > Testosterone > Androstenedione
In males, where are androgens converted to estrogen?
Cytochrome p450 aromatase
Primarily in the Adipose Tissue and Testes
Exogenous testosterone use...
↓ Hypothalamic-Pituitary-Gonadal axis → ↓ Intratesticular testosterone → ↓ Testicular size → Azoospermia
Why might you see increased androgens in a female?
Ovarian and Adrenal tumors
↑ DHT = Hirsutism = Male pattern hair growth
Hormone levels in Klinefelter syndrome
Dysgenesis of seminiferous tubules = *↓ Inhibin → ↑ FSH*
Abnormal Leydig Cell function = ↓ Testosterone → ↑ LH → ↑ Estrogen
Hormone levels in Tuner Syndrome
↓ Estrogen = ↑ LH & FSH
Premature ovarian failure
Premature atresia of ovarian follicles in women of reproductive age. Patients present with signs of menopause after puberty, but before 40.
↓ Estrogen → ↑ LH & ↑ FSH
Polycystic ovarian syndrome
Hyperinsulinemia or insulin resistance is thought to be the initiating factor.
Presents with enlarged bilateral cystic ovaries, amenorrhea/oligomenorrhea, hirsutism, acne, subfertility.
↑ Adipose aromatization = ↑ Estrone → ↓ FSH compared to LH & DHEA = *↑ LH : FSH ratio* = ↑ androgens from Theca Interna Cells → ↓ Rate of follicular maturation → Unruptured follicles (cysts) + anovulation = ↑ unopposed Estrogen = ↑ Risk of endometrial cancer
Ovotesticular disorder of sex development.
Both ovarian and testicular tissue present, ambiguous genitalia
Defective androgen receptor
↑ Testosterone & ↑ LH
Testosterone secreting tumor
Exogenous Steroid use
↑ Testosterone & ↓ LH
↓ Testosterone & ↑ LH
↓ Testosterone & ↓ LH
Ovaries are present, but the external genitalia are virilized or ambiguous in an XX infant.
Female Psuedohermaphrodite 🚺
Due to *excessive androgenic steroids* during early gestations
Congenital Adrenal Hyperplasia
Exogenous androgens during pregnancy
Testes are present, but the external genitalia are female or ambiguous in an male (XY) infant.
Male Pseudohermaphrodite 🚹
Most common form is *androgen insensitivity syndrome*
↑ serum testosterone and androstendione
Inability to convert androgens ➡️ estrogens
Masculinization of a female infant 🚺 (XX) = Ambiguous Genitalia
Can present with maternal virilization during pregnancy (fetal androgens can cross the placenta)
Normal appearing female with female external genitalia, with development of testes & ↑ Testosterone, estrogen and LH
Androgen Insensitivity syndrome (XY)
Defect in the androgen receptor sensitivity.
Genotypic male, *appears female* ➡️ female external genitalia, scant sexual hair, rudimentary vagina, ABSENT uterus and fallopian tubes.
5α Reductase deficiency
Limited to genetic males (XY) 🚹
Cannot convert testosterone → DHT
Ambigous genitalia until PUBERTY when ↑ testosterone causes masculinization and growth of the external genitalia... Internal genitalia is normal.
NORMAL testosterone and estrogen levels; thus NORMAL LH
Failure to complete puberty
Kallmann Syndrome = Hypogonadotropic Hypogonadism
Defective *migration* of GnRH cells and formation of the olfactory bulb (anosmia)
↓ GnRH, FSH, LH, & testosterone
Infertility (low sperm count in males and amenorrhea in females.)
17α- Hydroxylase Deficiency
↑ Mineralocorticoids = ↑ BP, ↓ K+
↓ Sex Hormones, ↓ Androstenedione
- 🚹 Male pseudohermaphroditism = Ambigous Genitalia, undescended testes.
- 🚺 Females lack secondary sexual characteristics
21- Hydroxylase deficiency
↑ Sex Hormones, *↑ 17-Hydroxyprogesterone* → Female virilization, Precocious puberty (childhood)
↓ Mineralocorticoids = Salt wasting (infants)→ ↓ BP → ↑ Renin
11β- Hydroxylase deficiency
↑ Sex Hormones → Female virilization 🚺
*↑ 11-deoxycorticosterone* = ↑ BP → *↓ Renin* → ↓K+
What do all the Congenital Adrenal Hyperplasia's have in common?
Enlargement of BOTH adrenal glands due to ⬆️ ACTH stimulation due to ⬇ ️Cortisol
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