CHAPTER 5: SLIDESHOW Flashcards
(58 cards)
Conception
Joining of two germ cells – the ovum (“egg”) and
sperm – to make a single cell called a zygote
(fertilized egg)
* Typically happens through male-female sexual
intercourse, but can happen through other
methods (e.g., IVF)
Where is ova stored?
Ovaries
Where are ovum stored inside of the ovary?
Follicle
What happens to follicles at puberty?
They grow and fill with fluid each month.
Ovulation
Around the middle of the menstrual cycle, one ovum is released from its follicle, and the other follicles that were growing typically become inactive.
When does the egg go after it’s released?
the fallopian tubes – two hollow tubes that extend from the right and left sides of the uterus
Uterus
the reproductive organ in which an embryo/fetus develops and is protected until birth.
Cervix
the lower, narrow portion of the uterus that
connects the uterus to the vagina, or birth canal.
When do male testes produce sperm?
They start at puberty and continue throughout a male’s lifetime.
What happens during conception?
semen, a liquid which usually contains over 100 million sperm, enters the female’s vagina.
* These sperm travel from the vagina to the cervix and through the uterus to reach the fallopian tube.
* Only 300 to 500 reach the correct fallopian tube to fertilize the egg.
* Many sperm approach the ovum and try to break through its surface. Only one sperm successfully enters, or fertilizes, the egg.
Once one sperm is accepted, no other sperm can enter the ovum. Conception has occurred, and the zygote forms.
How long does the sperm’s journey to the ovum take?
anywhere from 15 minutes to several days, depending on the female’s time of ovulation.
When does conception occur?
Conception usually occurs when the ovum is less than one-third of the way down the fallopian tube.
How long can sperm last in the female body?
5 days.
Pregnancy Timeline
Day one: First day of menstruation
* Around day 14: Ovulation occurs
* Within 24 hours of ovulation: Sperm fertilizes an egg
(conception occurs)
* About six days after fertilization: The fertilized egg implants
into the uterine lining
* Around day 21: If conception and implantation occurred during this menstrual cycle, you’re pregnant. However, getting a positive pregnancy test may take another five to seven days.
How long does pregnancy last?
40 weeks
3 stages of pregnancy
Germinal, Embryonic, Fetal
Germinal Stage
First two weeks after conception.
Embryonic Stage
Weeks 3-8
Chorion
the outermost membrane that surrounds the embryo in the uterus
Amnion
a fluid-filled sack that protects the baby until birth
Placenta
an organ filled with blood vessels, develops against the
wall of the uterus. As the placenta develops, it will nourish the embryo/fetus, remove the its wastes, exchange gases between pregnant person and embryo/fetus, and provide the embryo/fetus with needed hormones.
Umbilical cord
contains three blood vessels that connect the
embryo/fetus to the placenta. The umbilical cord grows out from the developing baby at the site of the future navel. It is connected to the placenta.
Fetal stage
9 weeks after conception. A baby is now known as a fetus.
Milestones in the fetal stage
Heartbeat – The heartbeat of the fetus can be heard through the doctor’s stethoscope (20 weeks pregnant)
* Movements – The fetus’s movements can be felt by the pregnant person, called quickening (18–20 weeks for first-time pregnancies; 15–17 weeks for following pregnancies)
* Age of viability – Age of viability is the time from when a baby can survive if born early. This time begins possibly as early as 23 weeks, but chances improve every week after until the full 40-week gestational period is over