Test 4: lecture 1 repo Flashcards
semelparous
dies after mating (salmon)
___ animals can reproduce multiple times throughout life
iteroparous
gonads in males and females
male→ testis, spermatozoa
female → ovary , oocytes
prototheria
monotremes
mammals that lay eggs (platypus)
theria
subclasses of mammals that give birth to live young
metatheria (marsupials)
eutheria (placental)
___ is released by the hypothalamus to stimulate the release of LH and FSH
Gonadotropin-releasing hormone (GnRH)
gonadoptropins
released by the anterior pituitary
Luteinizing hormone (LH)
• Follicle stimulating hormone (FSH)
LH and FSH will trigger the production of ___
Sex hormones:
estrogen
testosterone
progesterone
surge centers lead to ___
GnRH that tigger the release of LH
tonic centers will lead to the production of ___
GnRH that triggers the release of FSH
(slow frequency)
FSH in female binds to ___ cells, promotes follicular ____ and promotes differentiation of ___ cells
granulosa
development and oogenesis
theca
FSH in the male binds to ___ cells, and is required for the completion of ___
sertoli
meiosis
LH in females binds to the ___ cells and LH surge promotes ___
theca and luteal cells
ovulation
LH in males binds to ___ cells and stimulates ____production.
leydig
testosterone
where is estrogen produced
granulosa cells, placenta ect.
___ is produced by sertoli cells and inhibits spermatogenesis
estrogen
estrogen increases ___ receptors in the uterus
progesterone
progesterone is produced by ___
luteal cells and placenta
___ promotes gestation and behavior during diestrus
progesterone
will help increase cervical tone, make mucous thicker so sperm and bacteria can’t get in, decrease immune response in the uterus so that the fetus is not attacked
___ enhances development of secondary female sex characteristics
estrogen
___ drives the development of the mammillary gland
progesterone
Leydig cells and adrenal gland produce ___
testosterone
___ promotes development of internal genitalia and secondary sex characteristics in males
testosterone
testosterone is essential for ___ and sperm maturation
spermatogenesis
___ is made from testosterone and helps with the development of external genitalia development
DHT
dihydrotestosterone
Steroids are ____, therefore they cannot easily travel through the blood unless bound to proteins
hydrophobic
3 common binding proteins for steroid hormones are
Albumin
• Binds non-specifically with low affinity
Corticosteroid binding globulin
• Binds glucocorticoids and progesterone with high affinity
Sex hormone binding globulin
• Binds steroids with high affinity
DHT > T4 > androstenediol > estradiol > estrone
• When produced in the testes: AKA androgen binding protein
___ binds to glucocorticoids and progesterone with high affinity
Corticosteroid binding globulin
what is the order that sex hormone binding globulin will bind
DHT > Testosterone > androstenediol > estradiol > estrone
___ suppresses FSH release and is made by ___
inhibin and follistatin
Synthesized by granulosa (female) and Sertoli (male) cells
____ promotes FSH release and is made by
activin
Synthesized by granulosa (female) and Sertoli (male) cells
Promotes luteolysis in some animals
Prostaglandin-F2α (PGF2α)
___ causes cervical ripening prior to parturition
Prostaglandin E2
diagram of FSH and LH on sex hormones
Melatonin is released by the ___ gland and is involved with the circadian clock and alters the activity of ___ release
pineal
GnRH (seasonally mating)
prolactin is made by ___ in the ___
lactotropes
anterior pituitary
prolactin supports the ___ in some species and helps with mammary growth and ___
CL
lactation and maternal behavior
oxytocin is made by ___ and is associated with ____
hypothalamus → released in the posterior pituitary
uterine contractions, milk let-down (crying makes milk leak), bonding (males and females)
___ prepares the pubic symphysis and cervix for parturition. It is made by __
relaxin
made by the CL, endometrium and placenta
___ come from sex cords along the genital ridge
Follicle cells
Cells to become theca cells come from the ___
mesenchyme
Sertoli cells develop from cells in the sex cords of ____
genital ridge
Leydig cells come from the ___
mesenchyme
what are two things that can influence sex determination
environment → alligators change sex based on temp
chromosomes → SRY you are a boy
SRY
Sex-determining region on the Y chromosome (SRY) (AKA testis determining factor)
• Expressed in Sertoli cell precursors
• Transcription factor responsible for the formation of testes
• Activates SOX9
SRY → ⇡sox9 → testes
what genes are important for ovary development
NO SRY
Mechanism involves WNT4, RSPO1, and FOXL2
will a female have a wolffian duct or a mullerian duct?
mullerian
jost’s experiments:
what happens if you remove the testis?
what happen if you graph a testis into a female?
what happens if you add testosterone into a female?
wolffian duct degrades → female
mullerian duct degrades, wolffian duct persists → male one side
both wolffian and mullerian duct survive
testis needed to make male
the loss of the wolffian duct means ___
phenotypic female
also the ovaries have no direct connection to the tubes
that is why oocyte is released into peritoneal space and has to be picked up by the fimbriae into the tubes
___ causes the regression of mullerian duct and is made by the ___
mullerian- inhibiting factor
testes
Androgens promote further development of the Wolffian ducts into
the male reproductive tract
• DHT is critical for development of the external genitalia (thanks, 5α-
reductase!- enzyme from T4→ DHT)
what enzyme is needed to change testosterone into DHT
5α- reductase
___ is important for the development of the wolffian duct
___ is important for the development of the male external genitalia
testosterone
DHT
sexual differentiation of the brain
Testosterone is converted into estrogen in brain, resulting in an inactivation of the surge center of brain
no surge center = turns off GnRH that tigger the release of LH = no LH
why is surge center not turned off in a female?
alpha fetal binding protein binds to estrogen and prevents estrogen from going to the brain and turning of the surge center
In the presence of androgens: ___internal and external genitalia
male
Sexual ___results when chromosomal, gonadal, and/or phenotypic sex do not match
dysgenesis
now called disorders of sex development (DSDs)
XXY
(Klinefelter’s syndrome)
• Gonads: testes
- External genitalia: male
- Males have low fertility but appear otherwise male
true hermaphroditism
Individuals have both ovarian and testicular tissue
• Genital ducts and external genitalia vary phenotypically
- Can occur due to:
- Sex chromosome mosaicism
- Chimerism
Female Pseudohermaphroditism
A discordance between gonadal and phenotypic sex
Female pseudohermaphroditism results in ovaries and female genital ducts, with masculinization of the external genitalia
female pseudohermaphroditism
Q: How could this be?
Q: Why would this individual have female genital ducts?
XX: ovaries and female genital duct → male external
decrease in 21-hydroxylase that takes progesterone → minearlcorticoids
kidneys producing more androgens → this means there is an increase in T4 → DHT (which results in male external genitalia)
there was no AMH because there is no testes
male pseudohermaphroditism
Q: How could this be?
Q: Why could these individuals have regression of Müllerian ducts, and underdeveloped Wolffian ducts?
Male pseudohermaphroditism results in testes without complete masculinization of the genital ducts and/or external genitalia
- decreased DHT production = no external genitalia
- androgen insensitivity
- testes not making androgens