L13 Flashcards
Dihydrotestosterone
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I
I ENZYME (nazwa)
I
Testosterone5-alpha reductase
This enzyme is required for the normal male development of the external Genitalia in utero.
In absence of these hormones, female characteristics
Testosterone and a glycoprotein hormone called Mullerin inhibiting Hormone (MIH) required for male development.
Before …. weeks of gestation, the sex of the embryo is indeterminate
7-8
All embryos acquire dual ductal systems – ….
the Mullerian Duct and the Wolffian duct
Mullerian duct gives rise to ….
Wolffian duct give rise to ….
fallopian tubes and uterus
Vas deferens and Seminal vesicles.
In the female the Mullerian ducts … and the Wolffian ducts …. (default route).
develop
degenerate
In the male, …. inhibiting hormone causes the Mullerian duct to ….. and the testosterone …. the Wolffian ducts and also causes virilization of the external genitalia.
Mullerin
degenerate
differentiates
Testes –
source of germ cells and hormones
important for reproductive function;
Composed of seminiferous tubules where spermatozoa manufactured i.e. the sperm factory.
Secretion of Androgens: which bring about full masculine development.
Epididymis –
sperm spend at least 12 days in transit. Reservoir of sperm. But also sperm maturation.
Semen-
(2-6ml)
Sperm count 108 sperms/ml
(i.e 100 million/ml)
poszczególne elementy poniżej się na to składają: •ampullary gland •seminal vesicles (60%) •Prostate (20%) •bulbo-urethral glands
Secretions provide nutrients (fructose) for the sperm and secretions of the prostate is alkaline
Motility and fertility of sperm optimal at pH 6.5
Estrogens synthesised by the developing follicle
reaches a peak … before ovulation
2 days
The estrogen peak is responsible for the surge of
… release
both LH/FSH
… after…. peak ovulation takes place
12 hr
LH/FSH
Estrogens secreted by ….
follicle
Two major effects of estrogens:
• [1] It suppresses FSH release at low concentrations
• [2] At high concentrations it stimulates a surge of
both LH and FSH release
LUTEAL PHASE - opisz
After ovulation, the corpus luteum, under the influence of LH secretes both estrogens and progesterone:
Therefore:
•secretory endometrium develops
•Inhibition of secretion of FSH/LH.
Decrease in LH leads to degeneration of the corpus luteum, and a corresponding decrease in estrogens and progesterone.
Therefore endometrium begins to slough at conclusion of Day 28
Corpus luteum synthesizes and secretes ….. under the influence of ….
both estrogen and progesterone
LH/FSH
After Ovulation Progesterone supports the and …. also depresses ….
secretory phase of the endometrium
LH secretion
After Ovulation Estrogen alters ….. so that the release of ….
pituitary sensitivity to GnRH
LH/FSH diminishes
After Ovulation The corpus luteum no longer produces …. as the levels of …. drop and regresses to form ….
estrogens/progesterone
LH/FSH
corpus albicans
After Ovulation Decrease in … leads to the ….. and the cycle restarts again
oestrogens/progesterone
shedding of the endometrium
During Pregnancy, the …. is maintained
Corpus Luteum
For pregnancy to occur, Sperm must be present between … before and ….after ovulation.
Sperm remain capable of fertilizing an oocyte for … whilst an ovulated oocyte remains viable for ….
4 days before
1 day after
4-6 days
24-48hrs.
If Pregnancy occurs, the fertilised egg secretes …. (rozwiń skrót) and … (rozwiń skrót)
HCG (human chorionic Gonadotrophin)
HPL (human placental lactogen)
the basis of the pregnancy test - hormone name
HCG – human chorionic Gonadotrophin
HCG ~ similar to …
HPL ~ similar to ….
LH/FSH
prolactin (caused growth of mammary glands)
Pregnancy: HCG works like …
Therefore Corpus Luteum is now maintained for 3 months till …. takes over the secretion of ….
LH.
placenta
progesterone
and estrogens
Pregnancy: … can carry on for months
Lactation
During lactation, … is reduced, primarily mediated by ….
fertility
prolactin
Prolactin suppresses the ….
release of GnRH
Lactation can be suppressed by ….
which depresses prolactin release.
dopamine (bromocriptine)
…. antagonists allow prolactin release and hence milk synthesis
Dopamine
