Fertilization questions Flashcards
What is relaxin? Where does it come from?
What is inhibin?
a hormone from the placenta and ovaries assists in delivery. Relaxes the pubic symphysis and ligaments and dialetes the cervix
A hormone released by the placenta that inhibits the secretion of FSH
What is the embryonic stage?
What is the fetal period?
2nd - 8th week
8th week until birth
When does the placenta start working?
What decreases as a result?
end of the third month
hCG
What is Gastrulation?
What does it make?
What is the blastocyst now called?
Development of the three primary germ layers
Ectoderm
mesoderm
endoderm
The gastrula
What is the primary source of nourishment in the embryo. and the early site of blood cell formation?
Yolk sac
What is the protective membrane that forms around day 8 called? What is it filled with?
Amnion
Amniotic fluid
What is the fingerlike projections of the placenta called? What do they do/
Chorionic villi
Gas exchange
What is the placentas purpose ?
What two layered structure is it derived from?
Maintain fetus through oxygen and nutrients and waste disposal
Protective barrier against most microorganisms
Maintain pregnancy through secretion of hormones
Chorion
What is the umbilical cord composed of?
What are their functions?
one vein which carrries blood rich in nutrients to the fetus from placenta
2 arteries that carry carbon dioxide and wastes away from the fetus to the placenta
What is the lanugo and vernix? functions?
Fine downy hair - keeps fetus warm
Sebum and dead epidermal cells - waterproofing
What is the path of blood from the placenta to the fetus?
Umbilical vein then half goes to fetal liver, the other half bypasses the liver through the ductus venosus to the IVC
IVC to right atrium to right ventricle, then out pulmonary trunk
What structure allows the blood to bypass the lungs?
Ductus arterosus
What is the foramen ovale?
Hole in the atrial septum that closes when baby takes first breath.
Its a passageway between atriums
What are the three stages of labor?
Dilation
expulsion
placental stage
What is the stage of dilation?
Stage of expulsion ?
Placental stage?
Time from onset of labor to complete dilation of cervix
Time from complete cervical dilation to delivery
time after delivery until the placental is expelled
What does the baby secrete high levels of epinephrine and norepinephrine?
Because head compression during birth leads to intermittent hypoxia and you need a to have a strong breath at birth
What is the period where the maternal reproductive organs and physiology return to the pre-pregnancy state?
When does this happen?
What are the two things that happen?
Puerperium
forsix weeks after birth
Involution - catabolism of uterus tissue
Lochia - uterine discharge of blood and mucus
What prevents milk from secreting before birth?
What stimulates mammary gland development?
Progesterone
est. proges. placental lactogen
What is growth ?
Development?
increase in size
includes growth and changes in life phases that accomplish physiologic changes
What is it called when a second sperm is prevented from entering an egg?
Syngamy
In early development, how does the zygote divide?
What are the really small cells called?
When is it a morula? how long?
When is it a blastocyst? what is it?
What is the trophoblast?
What does it make?
Mitotically
Blastomeres
When it has 16-30 cells; 96 hours
5 days, hollow ball with inner cells
outer covering of cells beneath zona pellucida
Chorion
How does the blastocyst implant and how long does it take?
What is this called?
The trophoblasts eat away at the endometrium and embed there
Invading trophoblasts
Takes 6 days
What does hCG do?
mimics the LH by continuing secretion of estrogens and progesterone. Suppresses FSH to prevent cycling
What stimulates the first breath in infants?
rising CO2 and lowering pH
