Lecture 3 - Pregnancy and Physiological Changes Flashcards
what is ovulation
release of a mature egg from the ovary
what occurs at fertilisation
millions of sperm enter, but only around 300 make it to the egg and only one can fertilize the egg
what is formed during fertilization
zygote
what is a zygote
genetically complete (once the sperm and egg have combined)
after fertilization what will occur to the zygote, and what does this result in
cleavage will occur through the process of mitosis, ends up being a 16 stage cell morula
what is a morula, and what is its role
16 stage cell
- this helps bring nutrients into the cell, it is filled with fluid
what will then happen to the morula
it will form blastocysts
what are the two types of blastocysts formed from the morula (and what will they develop into)
- embryoblast : the fetus
- trophoblast : the placenta
when does implantation usually occur and what happens
occurs around day 10
- where the blastocyst will be implanted into the lining of the uterus and the embryo is formed
what does EDD stand for
estimated date of delivery
what is EDD usually counted from, and why is this used
typically counted from first day of last menstrual period (LMP)
- 40 weeks from last menstrual period
usually because the date of conception is unclear
when can EDD be also counted from
38 weeks from conception
what is the dates of the first trimester
conception until the 12th week
what are the dates of the second trimester
13th to the 28th week
what are the dates of the third trimester
28th week until birth
what is considered a pre term birth
<37 weeks
what is considered a term birth
37-42 weeks
what is considered a post term birth
> 42 weeks
the placenta is a …. what organ
temporary organ
when does the placenta begin forming
at the implantation of the blastocyst
when is the placenta fully formed and what happens after this
fully formed by 18-20 weeks, but continues to grow throughout pregnancy
what are the functions of the placenta
- carries oxygen, nutrients and antibodies from mother to fetus
- carries waste materials including CO2 form fetus to mother
during pregnancy what happens with the placenta and hormones
the placenta takes over some of the hormone production from the ovaries
what does the umbilical vein do
carries oxygenated blood and nutrients to the fetus
what does the umbilical artery do
removes deoxygenated blood back to the mother