Pregnancy & Development - Exam 4 Flashcards
Where does fertilization occur?
near ovary
Where does implantation occur?
in uterus
Gestation period
time from last mentrual period until birth (~280 days)
Embryo
fertilization through week 8
Fetus
week 9 through birth
How long is an oocyte viable?
12-24 hours
How long is sperm viable?
24-48 hours after ejaculation
For fertilization to occur, coitus must happen when?
two days before ovulation
24 hours after ovulation
In order for fertilization to occur, what must take place?
sperm must breach oocyte coverings
What is the acrosomal reaction?
acrosome (protective cap over head of sperm) has enzymes to allow for entry into oocyte
When does the oocyte do to protect against another sperm entering?
oocyte swells
What triggers the completion of meiosis II?
fertilization
From zygote to gastrula, explain the process of a fertilized egg
- Zygote - fertilized egg
- Cleavage - cell division with a decrease in size
- 4-Cell stage
- Cleavage
- Morula - ball of cells
- Blastocyst/Blastula - hollow ball of cells
- Implantation
- Gastrula - gastrulation
What is used for stem cell research?
blastocyst/blastula
Gastrulation
formation of 3 layers
allows for cell differentiation
When is implantation completed?
12th day after ovulation
What prevents menstruation?
-elevation of estrogen and progesterone
What keeps estrogen and progesterone elevated to prevent menstruation?
hCG
human chorionic gonadotropin
What takes the place of corpus luteum in hormone production?
placenta formation
What is the maternal aspect of the placenta?
blood pockets
What creates 3 germ layers in the embryo?
granulation
What are the 3 germ layers?
ectoderm
mesoderm
endoderm
Other than estrogen and progesterone, what else does the placenta secrete?
human placental lactogen (hPL)
relaxin
What does human placental lactogen do?
maturation of breasts
fetal growth
glucose sparing in mother (for fetus)