Reproduction Flashcards
What is a person’s biological sex based on differences in gonads or the organs that make gametes?
can have testes or ovaries
What is a person’s biological sex based on differences in chromosomes?
have 1 pair of sex chromosomes which can be XX or XY
What is a person’s biological sex based on differences in steroid hormones?
steroids like androgens and estrogen, inhibin, or activin
What is a person’s biological sex based on differences in reproductive anatomy?
internal reproductive anatomy and sex specific external genitalia used for assignment of sex at birth
In regards to gender what is the social definition of gender?
the social and societal constructs of norms behaviors roles associated with being a woman man girl and boy
In regards to gender what is the personal definition?
personal deeply felt identification of ones gender based on self awareness
What is the relationship between reproduction and homeostasis?
reproduction is the antagonist to homeostasis for an individual and is rather in regards to the species which means it may or may not be beneficial to individual
Why is the evolutionary compromise made in the male reproductive anatomy in which the testes are outside of the body?
the testes develop in the inner cavity where the ovaries in women develop and in males they come down from the abdomen pushing the intestines out of the way and they are pulled by a ligament which is attached to the abdomen wall and pull the testes down there is a hole called the inguinal canal which the testes fall down to near the scrotum
What is the vas deferens and what does it do?
is a duct which conveys the gametes made in the testes to the outside and it trails begind the desceding testes and is snagged behind the ureter
What does the urethra go right through?
the prostate gland
What does the prostate gland do?
the main organ that contributes secretions to the semen
What is the prostate gland highly sensitive to and what condition can this cause?
highly testosterone sensitive and it grows and hypertrophies and squeezes down on the urethra so in older men they have problems with urination and have to go more often and this is called benign prostatic hyperplasia BPH
What disease can the prostate gland’s sensitivity to testosterone cause?
can cause cancer because it is stimulated by testosterone
Why are the testes external to the abdomen while the ovaries are not?
production of sperm in the testes cannot happen at body temp so the sperm must be held outside the body in the scrotum which is 1-2 degrees C lower
What muscle wraps around the scrotum and is controlled by heat and cold sensitive nerves in the skin of the scrotum?
the cremaster muscle - in response to cold the muscle contracts and pulls up the testes into the abdomen and heat causes the muscle to relax so the testes tend to hang lower
What is the counter current heat exchanged which helps maintain testicular temperature?
maintenance of a cooler temp in the scrotum is hard if the artery brings body temp blood from the core of the abdomen so there is a venous drainage and they form a mesh with the arteries so the cool blood in the veins can exchange with the heated blood in the arteries so the blood in the veins is warm as it goes back ot the abdomen and the blood in the arteries is cold as it goes back down to the scrotum - this is well developed in marine mammals
What are the two main functions of the testes?
to produce gametes or sperm and secrete testosterone
What is the term for the tightly coiled tubules that have a gradient and are found in the testes and have different cell types?
seminiferous tubules
What is found in the outer basement membrane of semniferous tubules?
capillaries and leydig cells which are both outside the tubule
What do leydig cells do?
secrete testosterone at high levels in men even in old age; they also secrete a testosterone binding protein which keeps the concentration of testosterone inside the tubules really high compared to the outside so testosterone leaves
Damage to a boys germ cells due to the stress of starvation increases the rick of heart disease and cancer and fertility in who?
the grandchildren of that boy
What can environmental and chemical stressful damage cause in men?
can cause damage to the precursors of the spermatogonia and this can have long term effects in life
How do you get from spermatogonium (2n) to a spermatozoa?
spermatogonium (2n)—> primary spermatocyte (2n) – meiosis I—–> secondary spermatocyte (n) –Meiosis II–> spermatids (n) ——-> spermatozoa
What happens to the spermatids (n) generated by meiosis ii?
they get pushed into the epididymis which is continuous with the seminiferous tubules and get produced with the sperm - one day one hundred million sperm will enter the epididymis
What causes ejaculation?
the smooth muscle from the epididymis and the semniferous tubules contract
What makes up semen?
sperm and other fluids
How many sperm are in an ejaculate of a couple mL?
100 million sperm/mL - if you do not consistently ejaculate a few 100 million are attacked and the sperm get old
What is the endocrine control of testicular function?
the hypothalamus secretes GnRH ——> anterior pituitary gonadotropes ——-> FSH and LH; FSH——> sertoli cells and they cause spermatogenesis and secrete inhibin and activin
LH —–> leydig cell —–> testosterone—-> spermatogenesis
What cell type makes sperm in the seminiferous tubules?
Sertoli cells
What does kisspeptin a hypothalamic hormones do?
turns on GnRH secretion during puberty because prior to puberty it is off
What does neurokinin b a hypothalamic hormone do?
a peptide that stimulates LH secretion more than FSH
What does the hypothalamic hormone LPXRFa do?
inhibits GnRH
What does the hypothalamic neuron spexin do?
stimulates GnRH secretion and promotes satiety
What does the inhibin secreted by sertoli cells do?
go back and inhibit FSH
What does the activin secreted by sertoli cells do?
activates FSH and LH secretion and GnRH
What does testosterone inhibit?
LH and GnRH to do LH and FSH directly
What are the three layers of the uterine wall?
lumen, endometrium, myometrium
What are the arteries in the uterine wall?
radial arteries become spiral arteries as they enter the endometrium
When do precursor stem cells proliferate into oognoia?
during fetal life
At what time in a female’s life is the number of oogonia set?
at birth
During when in a female’s life is an oogonia going to undergo mitosis and give rise to another oognoia and one primary oocyte (2n)?
during fetal life
At birth a baby girl has how many primary oocytes (2n)?
about 2 million about half of which are defective so one million
On average how many primary oocytes develop and proceed to the next step of development and what is this step denoted by?
30 oocytes and this step is marked by a proliferation of granulosa cells and theca cells at the basal lamina to become a secondary oocyte and undergo meiosis I and 2n goes to n
How many primary oocytes go into meiosis i and how many secondary oocytes n are you getting?
one primary oocyte goes in and get two secondary oocytes and one of them dies so only one secondary oocyte
When does the secondary oocyte undergo meiosis II?
during fertilization with a sperm and forms a 2n zygote
The thirty oocytes a day which begin this process prior to puberty what happens to them?
they die
In order to complete their development these thirty oocytes a day have to begin this process just when LH and FSH levels are right during the months so how many will survive?
only 6-10
What doe the granulosa cells and theca cells do when there is secondary oocyte ready for ovulation?
granulosa cells create a fluid and theca cells make digestuve enzymes to weaken the connectuve tissue of the ovarian follicle so that with pressure from the fluid the follicle ruptures and the oocyte will pop out as an oocyte surrounded by granulosa cells and only one oocyte makes it to this stage
What is the endocrine control over ovarian function?
hypothalamus —-> GnRH —–> antPt (FSH and LH) FSH—–>Ovarian follicle granulosa cells —-> cause testosterone to be made into estradiol (estradiol has a positive feedback loop on granulosa cell causing more testosterone to be make into estradiol)
LH—–> theca cells ——> testosterone
What elso do granulosa cells secrete?
inhibin and activin
What does inhibin inhibit?
FSH and LH
What does activin activate?
- testosterone production by theca cells
- FSH and LH
- GnRH
- Testosterone conversion to estradiol
What does estradiol inhibit?
GnRH
FSH and LH
What is menopause?
the cessation of menstrual cycles and the symprtoms takje a few years to trun its course
What causes the symptoms of menopause?
declining estrogen - causes dryness in vagina and lose bone strength - dyring and itching of skin and cardiovascular problems and urinary incontinence, hot flashes due to vasodilation in skin due to blood vessels dilating in the skin amnd they coincide with LH sceretion
What is indicatuve of full menopause?
FSH and LH levels are high
What is the adaptive hypothesis for the evolutionary significance of menopause?
evolution favored women who becamse fertile years before death to care for older children vs having new children and the grandmother hypothesis
What is antagonistic pleiotropy in menopause?
one gene producing two effects one good and one bad - menopause is an epiphenomenon or secondary effect
Since menopause is known as a drop in estrogen production and estrigen levels are low in women during lactation after giving birth what are some of the similarities between the two symptomatically?
bone weakening - to put milk in for baby
vasodialtion - skin warms so baby suckles
-atherscelosis - help mobilize fat to put in baby milk
What forms the corpus luteum?
remanants of teh graffian follicle and granuolsa and theca cells and pump out high levels of estrogen and progesterone after ovulation
What is the corpus luteum dependent on?
gondaotropins, they decrease and the corpus luteum shrink and becomes a white scar tissue knwon as the corporal albicans; but if implantation happens the embryo will make endocrine tissues whcih will secrete lh and rescuse the corpus lutueum and HCG will save it to during preganncy
While the ovarian follicle is growing during the follicular phase why are FSH and LH low?
because the ovarian follicle is growing and the FSh and LH tell the granulosa and theca cells to make testoeterine or make estrdaiol fromtestostoerone the products gop back and inhibit FSH and LH via inhibin and estradiol
During ovulation why do FSH and LH in particular spike alot?
they spike because the begatuve feedback of estrogen becomes a positive feedback system on lh and fsh causing LH to spike - after ovulation during the proliferative phase LH drops and fsh does to because the cells granulosa and theca cells are injured when the oocyte burst
With the formation of the corpus luteum during the luteal phase what happens?
estrigen and inhibin and progtesterone productuin increase cause it rescues it - this falls off because the corpus luteum dies - if fertilization occurs zygote will make which will rescue the corpus luteum - then placenta is made and that takes over estrogen and progesterone
What are the two characteristic types of tissues in the endometrium?
the spiral arteries which prvoide blood flow and the invaginated pit exocrine glands which secrete a glycogen rich mucus to nourish the embryo
-it is estrogen sensitive meaning it will shed when estrogen decreases
What drive the mucus secretion from the endometrium to noursih embryo?
progesterone
Steroid hormones suppress what?
prostaglandin which constructs the arteries in the utertus so that tehy remain dilated and when steroid levels drop then prostaglandin inhibition stops and the endometrium is shed by necorsiss and dies - as shedding happens prostaglandin decreases so vasoconstricition is done so that means there is bleeding when shedding happens - they also stimulate uterine contractions so that the blood clots and tissues leave
Where does the oocyte spit out into?
the abdominal cavity and the oviduct uses fimbiraw to wrap around the ovary and take it into the lumen of the fallopian tube
Higher hormone levels around ovulation cause the cervix to have what?
an opening and lose the thick acidic mucus lethal to sperm
The acrosome of the sperm head does what to get through teh granuloisa cells surrounding the oocyte?
has proteolytic enzyme which digest the adhesive proteins and glycosaminoglycans which swell
How do you prevent polyspermy?
oocyte would open calcium channel when fertilized and depolarize and change conformasuion so it cannot interact with otehr sperm
What do the outer layers of the blastocyst do?
form finger like projections to grow into endometrium and kill the cells of the endometrium
What does the placenta do?
oxygenats fetal blood via umbiilkics cord which ois tha rtery and vein
What do the villi of chorion do?
interact woth maternal blood and give it back to the fetus
What do the anchoring and floating villi do?
attch placenta to endometrium
What secretes HCG and is the basis of a pregnancy test?
chorion
When does preeclampsia start?
after 20 weeks of pregnancy
What are the main symptoms?
hypertension and proteinuria
liver disease, hemolysis, low platelets, pulmonary edema
What is preeclampsia?
abdnormal formation of placenta and sectetion of antioangiogenic factors and inflammatory signals - fetus wants hypertension in mother so does not bnecome too big to deliver and comes form the cytotrophoblasts not being able to displace the mothers maternal endothelial cells and cause the blood vessels to dilate
What is the endocrine control of lactation?
sucking —-> stimulates nipple mechnoreceptors—> hypothalamus dopamine drops and PRH incteases —–> ant pit release prolactin —> milk synthesis
post pit —–> oxytocin and milk ejection
What stimulates growth of alveoli in breats?
progesterone
What is placental lactogen?
hormone secreted by fetal half of placenta and causes prolactin like effects of milk production but it is ihibited by high levels of estirgen and progesteorne so need to wait till after birth
What does human milk have?
high in fat and lactose and has beneficial bacteria for baby
