reproductive systems 14.3 Flashcards
y chromosome has a gene called the ____
testes determining factor (TDF)
male sex hormones=
androgens
puberty begins between ages ___ for males
10-13
GnRH comes from ___
hypothalamus
GnRH begins ___
puberty
GnRH stimulates_____
anterior pituitary to release FSH and LH
FSH begins
sperm production
LH releases
testosterone from testes
FSH causes production of sperm in __
seminiferous tubules of testes
Sperm production in seminiferous tubules causes the release of __
Inhibin from tubules
Inhibin inhibits___
production of FSH in anterior pituitary to keep sperm levels constant (negative feedback)
LH causes production and releases of ___
testosterone
testosterone inhibits release of ___
LH from anterior pituitary to keep testosterone levels constant
andropause:
declining testosterone levels with aging (loss of muscle, decreased sperm production etc)
puberty for females begins between the ages of ____
9-13
LH and FSH in females stimulate ___ +____
estrogen and progesterone production in ovaries
menstrual cycles consists of which 2 cycles
ovarian and uterine
menstrual cycles=
period when ovum is released and uterus prepared for implantation of fertilized egg
first stage of menstrual cycle + what happens
menstruation
endometrium disintegrates and is shed if no egg is fertilized
ovarian cycle is divided into 2 stages
follicular and luteal stages
what happens in the follicular stage of the ovarian cycle (5)
- increased FSH causes one follicle to mature
- maturing follicle releases estrogen (mainly) and progesterone
- this triggers the release of GnRH
- LH spike
-ovulation
estrogen thickens ___
endometrium
ovulation=
follicle ruptures and releases ovum into oviduct
what happens in the luteal stage (4)
- follicle developed into corpus luteum due to LH
- corpus luteum secrets estrogen and progesterone (mainly)
- FSH and LH prodcution is therefore inhibited
- corpus luteum degenerates so FSH and LH aren’t inhibited anymore
if fertilization and implantation occurs what maintains estrogen and progesterone levels
HCG (human chorionic gonadotropin)
after fertilization progesterone ____ and estrogen _____
Maintains endometrium to support developing fetus
stops ovarian cycle (no more follicles mature)
Uterine cycle ensures
that the uterus is ready for a fertilized egg
tissues and blood vessels of endometrium to support life are developed in what cycle
uterine cycle
endometrium disintegrating =
menstruation
proliferative stage is days ___
6-12
secretory stage is days ___
14-28
what happens in the proliferative stage(2)
-corpus luteum degenerates- low hormone levels- new follicle matures and releases estrogen
- estrogen levels in blood increase and endometrium thickens
what happens in the secretory stage
progesterone is released after ovulation therefore endometrium wall thickens rapidly
if no fertilization occurs the ____ degenerates
corpus luteum
after puberty number of functioning follicles ____
decreases gradually due to a drop in estrogen and progesterone levels
menopause is ___ and usually occurs around the age of _____
the end of the menstrual cycle
age 50
