Practical Applications of Physiology Flashcards
(64 cards)
How did the ancient Egyptians detect pregnancy?
women who suspected they were pregnant would urinate on grain seeds (wheat and barely) every day for 10 days.
the rapid sprouting of these grains would indicate pregnancy. the sprouting wasnt caused by the hCG hormone but instead the elevated levels of estrogen. this was discovered as the pee on grain method still worked after the urine was boiled denaturing the hCG but not estrogen.
it was originally believed if the barley sprouted first you were having a boy and wheat meant girl.
What in the pregnant urine indicates pregnancy?
the presence of the hCG hormone.
What is hCG?
human chorionic gonadotropin.
a peptide hormone secreted by 6 day embryo (blastocyst) and placenta after implantation.
it was discovered in 1927.
what is a follicle?
a sac in the ovary that holds the egg
what is luteinizing?
turning the empty follicle (after ovulation) into corpus luetum
how many eggs are baby girls born with?
1-2 million
how many egss do girls have once they reach puberty?
0.3 - 0.4 million follicles are left
how many eggs will ovulate in a womens body?
300 - 400
What is chorion?
the outer fetal membrane that develops from trophoblast.
what is gonadotropin?
the hormone that acts on ovaries to produce other hormones.
how is progestereone and estrogen produced?
hCG keeps corpus luteum alive to produce p and e.
when hCG drops, corpus luteum regresses -> placenta takes over to produce p and e.
when in pregnancy does hCG spike?
it spikes in the first 2 months of pregnancy and drops to a lower level for the 3rd to 9th.
when does progesterone spike?
during pregnancy progesterone steadily increases to peak at a very high level during delivery then shooting back down after.
when does estrogen spike during pregnancy?
similarly to progesterone it steadily increases until delivery, reaching its peak, which is half of progesterones peak, and then it falls back down post delivery.
whats the aschheim-zondek (A-Z) pregnancy test?
used young (immature) female mice: 5 per urine sample.
each mice was injected with a suspecting pregnant womans urine twice daily for 3 days (30 injections overall)
the mice were then cut open to inspect their ovaries which would give a positive or negative result
disadvantages to the aschheim-zondek pregancy test
time consuming
unethical - all mice were euthanised 100 hours after first injection
advantages to the aschheim-zondek pregnancy test
reliable, scientific way to test pregnancy
how would the mouse indicate pregnancy?
once you cut open the mouse you would inspect its ovaries.
a positive test was indicated by enlarged uterine horns, red spots (ovulation sites), and the presence of corpora lutea.
the reason the pregnant urine affects the mouse like this is because it contains hCG which has a similar molecular structure to LH the hormone that causes ovulation in mice. they both bind to the same receptor to trigger steroid hormone production.
what is the freidman pregnancy test?
the test involved 1-2 adult rabbits per urine sample.
a single injection typically into the rabbits ear.
after 2 days the rabbit would be cut open to inspect the ovaries for red spots and corpora = pregnancy
how was the friedman test advantageous?
if the test was negative the rabbit would survive, be stitched up and used up to 3 times.
less injections.
results came after 2 days.
how was the friedman test disadvantageous?
for each positive test a rabbit would die or after 3 negatives.
cruel to animals.
what is the hogben test?
using adult female african clawed frogs, scientists would give them a single urine injection and in the next 12 hours the frogs lay eggs that meant the sample was a pregnant sample
why was the hogben test disadvantagous?
cruel to the frog
had to be done by a scientist.
why was the hogben test advantageous?
eggs are laid externally so not need to open the frog.
frogs could be reused and live up to 30 years.
easy to keep and breed in labs.
nearly 100% reliability.
