Oogenesis Flashcards
What is the process called by which male and female gametes fuse to form a zygote?
Fertilization
Occurs in the ampulla of the uterine tube.
Where does fertilization usually occur?
Ampulla of the uterine tube
The ampulla is the longest and widest part of the tube, close to the ovary.
What percentage of sperm deposited in the vagina enter the cervix?
One percent
Only a small fraction of sperm successfully migrate past the cervix.
How long does it take for sperm to migrate from the cervix to the oviduct?
2 to 7 hours
This migration is essential for reaching the fertilization site.
What happens to sperm motility after reaching the isthmus?
Sperm become less motile and migration ceases
This is a temporary halt until ovulation occurs.
What triggers sperm to become motile again at ovulation?
Chemo-attractants produced by cumulus cells
These attract sperm to the egg.
What are the two processes spermatozoa must undergo to fertilize the ovum?
Capacitation and acrosome reaction
Both are essential for successful fertilization.
What is capacitation?
A conditioning period in the female reproductive tract lasting approximately 7 hours
Involves interactions between sperm and the mucosal surface of the uterine tube.
What happens to the glycoprotein and seminal plasma proteins during capacitation?
They are removed from the plasma membrane overlying the acrosomal region
This is necessary for sperm to be able to fertilize the egg.
What must happen for sperm to pass through the corona cells?
They must be capacitated
Only capacitated sperm can undergo the acrosome reaction.
What induces the acrosome reaction?
Binding to the zona pellucida induced by zona proteins
This reaction is crucial for penetrating the zona pellucida.
What enzymes are released during the acrosome reaction?
Acrosin and trypsin-like substances
These enzymes are needed to penetrate the zona pellucida.
