Reproductive System Part 3 Flashcards
fertilization is the
fusion of gametes (egg and sperm) to form the zygote
where can fertilization occur?
in vivo
in vitro
only ______ is normally released during the menstrual cycle
one oocyte
following ovulation, the oocyte starts
undergoing an aging process
this aging process, leads to
egg infertility
egg is fertile for about
24 hours
each ejaculation released
200 - 300 million spermatozoa
_______ of spermatozoa will reach the site of fertilization
a very low percentage
the cervic and uterofalloian junction is a
hostile environment
what destroys most of the spermatozoa?
female immune system
be more specific with what immune defense is found in uterine lumen
neutrophil granulocytes
macrophages
is the killing of spermatozoa good?
yea, selects for the strongest sperm
spermatozoa remain fertile for a maximum of ___ in the female reproductive system
2 days
name the 2 functional modifications spermatozoa need for fertilization to take place
- spermatozoa undergo maturation in the epididymis
2. spermatozoa undergo capacitation in the female reproductive system
because of their size, sperm have
limited resources
why is timing of motility off sperm important?
motility is very energy consuming and there is a great distance to travel
_______ of the ovum form barriers to fertilization
extra-cellular layers
what facilitates the acquisition of motility?
sperm maturation in the epididymis
what triggers motility?
ejaculation of semen into the female reproductive tract
sperm gradually become more motile after they
enter the female reproductive tract
what does chemotaxis do?
chemical signals released by ovum that attracts sperm to the egg
sperm require a period of maturation in the female reproductive tract before what?
they are capable of fertilizing the egg
capable of fertilizing the egg takes about
5 to 6 hours
capacitation takes place in
uterus and oviduct
capacitation alters the
sperm plasma membrane
T/F Capacitated sperm show greater respiratory activity and motility than noncapacitated sperm
true
define acrosomal reaction
initiated as sperm proceed through the corona radiata and approach the zona pellucida
_____ stored in the acrosome escape into the region surrounding the sperm
enzymes
what do the enzymes do?
loosen connections between cumulus oophorus or corona radiata cells
what do the enzymes allow?
sperm reach the zona pellucida
_______ restricts inter-species fertilization
zona pellucida
eggs are surrounded by the
zona pellucida
after sperm penetration, zona pellucida undergoes a structural change known as
the zona reaction
the outer most layer of egg contain
sperm receptors on the vitelline envelope
what is the fertilization cone?
extension of egg cytoplasm that engulfs the sperm
sperm and egg nuclei combine to form the
diploid zygotic nucleus
____ is a late response to fertilization
synkaryon
what happens if fertilization does not occur?
the ovum disintegrates and is destroyed by the fallopian tube
the early reaction of egg to fertilization
prevents polyspermy
the late response of egg to fertilization
lead to formation of embryo
prevention of polyspermy allows
only one sperm to fertilize egg
prevention of polyspermy prevents
polyploidy (more than 2 sets of chromosomes)
polyploidy will ultimately cause
the death of the embryo
the cortical reaction consists of the
exocytosis of the contents of the cortical granules
vitelline envelope is called the ____ envelope
fertilization
once egg and sperm join, what happens to vitelline envelope?
its elevated above the egg surface
why is viline envelope elevated?
increases distance between egg plasma membrane and vitelline membrane and increases distance the supernumerary sperm have to trave
cortical reaction makes the vitelline envelope
hard
why is it good that vitelline envelope is hard?
so its resistant to digestion by sperm proteases
finally, sperm receptors on the vitelline envelope are
destroyed
__________ the egg is arrested in metaphase of the second meiotic division
prior to fertilization
division process is reactivated by
the penetration of the sperm
sorry ain’t finishing this
good luck!
