Reproductive System Part 2
After the sperm enters the oocyte, the oocyte completes ________ __.
Meiosis II
After 72 hours, ______ is formed from cleavage.
Morula
Amniotic fluid is derived from _____ _____ but then derived from kidneys but mostly is water.
Mother's blood
Does the process of implantation immediate?
No it takes about 5 days
Are cells growing in size during cleavage?
No, but they have production of more cells to increase surface area and volume ratio
Does early bird always get the word in sperm terms?
No; need other sperm for this process to happen
Viable 12-24 hours post ovulation.
Oocyte
In a cortical reaction, ____ ____ hardens and sperm detaches and are no longer able to attach to this structure.
zona pellucida
Develops from trophoblast.
Chorion
In post-implantation, ______ develops from trophoblast, takes over stimulating corpus luteum.
Chorion
What develops in post implantation?
Chorion
What develops into the fetal part of the placenta?
Chorion
Chorion develops ____ ____ that form part of the placenta.
Chorionic villi
Period of rapid mitotic divisions.
Cleavage
______ events form blastomere.
Cleavage
What prevents polyspermy?
Cortical reaction
______ ______ of sperm enter the oocyte. _____ ____ stays behind and ____ _____ are released into the oocyte.
Cytoplasmic contents; plasma membrane; internal contents
The initial cell in fertilization.
Zygote
Trophoblast gives rise to ___ of the extraembryonic membranes.
1 (placenta)
An oocyte is viable __-__ hours post ovulation.
12-24
Morula is made up of how many cells?
16 or more cells
In 36 hours, the 1st cleavage creates __ _____ ____.
2 identical cells
When does extraembryonic membranes develop?
2-3 weeks after fertilization
A sperm is viable __-__ hours post ejaculation.
24-48
In the final step of fertilization, __ nuclei fuse forming the ______.
2; zygote
What is the maximum amount of time an oocyte can be fertilized?
3
How long does the gestation period last? (Days and months)
About 280 days and 9 1/2 months
Sperm releases acrosomoal enzymes that digest holes through the zona pellucida.
Acrosomal reaction
Membranes become thin in capacitate sperm so that enzymes can be released from _______.
Acrosome
Organelle around the head of sperm that contains hydrolytic enzyme.
Acrosome
When should you wait to take a pregnancy test?
After a missed period because there can be false negatives due to hCG not being high
Becomes part of embryonic urinary bladder.
Allantois
Forms as outpocket from end of yolk sac
Allantois
Transparent membranous sac that fills with amniotic fluid.
Amnion
What two extraembryonic membranes develop from inner cell mass of blastocyst?
Amnion and yolk sac
What are the extraembryonic membranes?
Amnion, yolk sac, allantois, and chorion
Fertilization takes place in the ____.
Ampulla
When is hCG released?
At implantation
Why do we want membranes thick at first?
Because if not, sperm would be killed
What is another name for blastocyst?
Blastocil
Cluster of about 100 cells.
Blastocoysts
Amnion develops from inner cell mass of ______.
Blastocyst
In 4-5 days, ______ is formed.
Blastocyst
Two identical cells from first cleavage.
Blastomeres
What is formed after initial cleavage events?
Blastomeres
Part of the yolk sac can become restricted and develops into the ______ part of the embryo.
Digestive
Dorsal surface of developing embryo.
Ectoderm
What are the primary germ layers?
Ectoderm, endoderm, mesoderm
What is the developing young in the embryonic period called?
Embryo
When does cleavage happen?
Embryonic Development
Fertilization to week 8 of gestation.
Embryonic period
6-7 days implantation of blastocysts into ____ begins.
Endometrium
In a capacitate sperm, sperm motility is enhanced/degraded?
Enhanced
What released by oocytes destroy sperm receptors?
Enzymes
Thin membranes surrounding embryo.
Extraembryonic membranes
Fertilized egg travels from distal end of ______ tube to the _____. What kind of event is this?
Fallopian tube; uterus; cleavage event
T/F: Sperm cannot be destroyed by the acidic environment.
False
Sperm's chromosomes combine with chromosomes of secondary oocyte forming a zygote.
Fertilization
Week 9 to birth.
Fetal period
Developing young is called ____ in the fetal period.
Fetus
What are the functions of amniotic fluid?
For cushioning/protection of the developing embryo, temperature regulation, allows for embryo to move around in uterus which is important for muscle development
Formation of 3 primary germ layers.
Gastrulation
Length of time woman is pregnant (duration time).
Gestation period
In the first part of fertilization, sperm releases enzymes that digest junctions between _____ and _____.
Granulosa cells; surrounding oocyte
At implantation, _____ released from trophoblasts, stimulates corpus luteum to keep secreting estrogen and progesterone.
Human chorionic gonadotropin
What hormone is detected by home pregnancy tests?
Human chorionic gonadotropin
What is the young called after it is born?
Infant or newborn
Forms embryo and 3 of the 4 extra embryonic membranes.
Inner cell mass
Yolk sac develops from...
Inner cell mass of blastocyst
Internal cluster of 20-30 cells.
Inner mass cells
What are some fates of sperm?
Leak out of vagina, destroyed by acidic environment in vagina, blocked at the cervix due to thick mucus, phagocytes destroy them, reverse peristalsis
_____ part of the placenta are arteries and blood vessels in the endometrium.
Maternal
Chorion develops into fetal part of the _______.
Placenta
____ sperm binds & fuses to what during fertilization?
Plasma membrane of oocyte
Multiple sperm entering oocyte.
Polyspermy
Events that occur during gestation period.
Pregnancy
Events that occur from fertilization until infant is born.
Pregnancy
Contraction of uterus in the opposite direction.
Reverse peristalsis
What guides sperm to oocyte & secretions in female reproductive tract capacitate sperm?
Reverse peristalsis
Viable 24-48 hours after ejaculation.
Sperm
In cleavage, cells are not growing but have production of more cells to increase ____ _____ and to ____ ____.
Surface area; volume ratio
Groups of cells in blastocyst.
Trophoblasts
Single layer os large periphery that are flattened cells.
Trophoblasts
What aids in implatation and in placenta formation?
Trophoblasts
What protects the embryo from mother's immune system?
Trophoblasts
T/F: Pregnancy strips have antibodies on them.
True
Arteries and veins that connect embryo to placenta.
Umbilical cord
In the allantois membrane, blood vessels become part of _____ _____.
Umbilical cord
As cells divide, the ova moves towards to ______.
Uterus
Can an oocyte be fertilized by a sperm that has been hanging out before ovulation has occurred?
Yes
Can phagocytes destroy sperm?
Yes
Can some sperm leak out of vagina?
Yes
Does amniotic fluid allow for the embryo to move around in the uterus?
Yes
Does cleavage enhance nutrient and oxygen uptake?
Yes
Does hCG start to double a couple of days after implantation?
Yes
Fluid-filled cavity forms and zona pellucida breaks down in a blastocyst.
Yes
Provides some nutrients to developing embryo prior to placenta taking over.
Yolk sac
The function of what extraembryonic membrane is not as prominent in humans and functions for a small amount of time?
Yolk sac
After sperm digest junctions between the granulosa cells and surrounding oocyte, what does sperm bind too?
Zona pellucida
Fusion of two nuclei form a ______.
Zygote