3 Pregnancy Flashcards
The upper, middle, and lower parts of the uterus are called?
- fundus
- body
- cervix
What is the function of hCG?
- to tell the Corpus Luteum to keep making Progesterone!
- this prevents sloughing off endometrium, keeps zygote viable!
What secretes hCG?
Trophoblast of the baby
What does the trophoblast eventually become?
-Placenta
Why, during the 2nd and 3rd trimesters, do we not need the corpus luteum anymore?
-now the Placenta is big enough to make its own Progesterone, which maintains itself
Describe the relationship between the placenta and the fetal pituitary.
(placenta uses baby to make extra Progesterone!)
Placenta stimulates fetal pituitary to make ACTH
Baby makes DHEA in its adrenal.
DHEA converted in placenta via aromatase to PROGESTERONE!
So why the hell is DHEA the only water soluble steroid hormone?
it has to be sulfated so it can cross INTO the placenta in order for it to be converted to progesterone!
The placenta secretes __________ which has effects similar to growth hormone on mom (lipolysis, insulin insensitivity, increases blood glucose)
hPL (human placental lactogen)
aka hCS (human chorionic somatomammotropin)
hPL increases around the 2nd trimester. Describe the benefit it has for the baby?
the greedy baby prevents mom from getting nutrients (insulin resistance) and shunts more stores+nutrients to baby
What hormone is the cause of gestational diabetes?
hPL
PRL, estrogen, and progesterone all gradually __________ throughout the pregnancy
increase
How long does the secondary oocyte last once its ovulated?
12-24 hours
How long does a sperm last inside the female reproductive tract?
24-48 hours
A sperm interacts with a what type of oocyte, and what is its N?
sperm meets secondary oocyte (2N)
What are the steps involved in a sperm meeting the oocyte?
- passage thru corona radiata
- binding to zona pellucida
- fusion of membranes
- secondary oocyte moves on from Metaphase II
- male pronucleus forms
Once the oocyte is fertilized, how does it grow?
- stays contained by zona pellucida
- more cells, but not bigger!
What day does the zona pellucida break down?
~day 5 after fertilization
The final stage of the embryo inside the zona pellucida is a big ball of 16-32 cells called a ________
Morula
not a morula from Ehrlichiosis!
The zona pellucida breaks down, and the embryo grows a cavity inside. What’s it called now?
Blastocyst
How does a sperm get thru the zona pellucida?
Acrosome reaction (secretes enzymes that break it down locally)
What structures reduce more sperm from getting thru the zona pellucida?
Cortical granules
inactivate sperm receptors, harden pellucida
What event marks the formation of an embryo?
fusion of the 2 pronuclei (becomes haploid again)
At implantation, the trophoblast of the blastocyst secretes _________ while the endometrial cells secrete ________
proteolytic enzymes
Prostaglandins
What is the area of modified endometrium around the implantation site?
decidua
