Download The Very Beginning - Sarah E. Goode STEM Academy

Prenatal Development
and Care (2:38)
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As a fetus develops during pregnancy,
special care needs to be taken to
ensure the fetus and mother remain
healthy.
The Very Beginning
Did you know?
A single cell, formed from one egg and
one sperm, can grow into a complex
human being.
The Very Beginning
The human body begins as one microscopic cell
that is formed by fertilization, also known as
conception.
Fertilization
The union of a male sperm cell
and a female egg cell
The Very Beginning
The cell that results from fertilization is called a
zygote.
The zygote begins to divide and travel through the
fallopian tube.
The Very Beginning
The Very Beginning
Within a few days, implantation occurs.
Implantation
The process by which the
zygote attaches to the
uterine wall
The Very Beginning
After about two weeks, the zygote becomes an
embryo.
Embryo
A cluster of cells that develops
between the third and eighth
week of pregnancy
The Very Beginning
The embryo is called a fetus after about eight
weeks.
Fetus
Group of developing cells
The Growing Embryo
Eventually, the embryo forms three layers of tissue.
One layer becomes the respiratory and digestive
systems.
A second layer develops into muscles, bones, blood
vessels, and skin.
The third layer forms the nervous system, sense
organs, and mouth.
The Growing Embryo
The amniotic sac is a thin, fluid-filled membrane
that surrounds and protects the developing
embryo.
The umbilical cord is a ropelike structure that
connects the fetus with the mother’s placenta.
The Growing Embryo
The placenta is thick, blood-rich tissue that lines
the walls of the uterus during pregnancy and
nourishes the embryo.
The Growing Embryo
The Growing Embryo
The Growing Embryo
The Growing Embryo
Multiple Births
In most cases, fertilization results in one embryo.
Twins, triplets, and quadruplets, known as multiple
births, can result when multiple embryos are
formed.
Multiple Births
Identical
Twins
Single zygote that splits
into two separate
embryos.
Identical traits and
the same gender.
Fraternal
Twins
Two eggs are released
and are fertilized by two
different sperm.
Can be different
genders.
A Healthy Pregnancy
A pregnant female can maintain the health of
her fetus in many different ways.
Seeing a doctor regularly throughout the
pregnancy will provide a new mother with the
care and nutritional advice she needs.
A Healthy Pregnancy
A pregnant woman needs prenatal care to ensure
her health and that of her growing baby.
Prenatal care
The steps that a pregnant
female can take to provide for
her own health and the health
of her baby
What to Eat While Pregnant
Pregnant females are encouraged to take prenatal
vitamins to provide a balance of nutrients.
What to Eat While Pregnant
Calcium helps build bones and teeth, nerves, muscles, and heart.
Protein helps form muscle and other tissue.
Iron makes red blood cells and supplies oxygen to cells.
Vitamin A helps in the growth of cells and bones and in eye
development.
Vitamin B complex aids in forming the nervous system.
Folic acid is critical in development of central nervous system.
What to Eat While Pregnant
Females at a healthy weight
before becoming pregnant
can gain between 25 and 35
pounds during pregnancy.
Fitness During Pregnancy
Physical activity can help a pregnant female
maintain a healthy weight during pregnancy.
Before starting any exercise program, an
expectant mother should discuss the importance
of exercise and exercise programs with her health
care provider.
A Healthy Fetus
Expectant mothers should avoid tobacco,
alcohol, drugs, and environmental hazards.
An expectant mother should avoid substances
that can harm her and her fetus.
Avoid Tobacco Use
Exposure to secondhand smoke increases the risk
of having a low-birth-weight baby.
Smoking may also affect growth, mental
development, and behavior after a child is born.
Avoid Alcohol Use
Fetal alcohol syndrome can cause learning,
memory, and attention problems, as well as visual
and hearing impairments.
Fetal alcohol syndrome
A group of alcohol-related birth
defects that includes both
physical and mental problems
Avoid Drug Use
Prescription or over-the-counter medications
should be used only with the approval of a doctor
or other health care professional.
In some cases, drug use may lead to the
premature birth of the infant, or even a
miscarriage.
Avoid Hazards in the Environment
A pregnant female should avoid these common
hazardous substances in the environment.
Lead
Mercury
Smog
Radiation
Avoid Hazards in the Environment
Activities such as painting
or using lead-based
products should be avoided
or done carefully during
pregnancy.
Complications of Pregnancy
A pregnancy may have an unexpected
outcome.
Most pregnancies result in the birth of a healthy
baby.
Complications of Pregnancy
The complications of pregnancy can result in
a cesarean delivery, made through an incision
in the mother’s abdomen.
premature birth, at least three weeks before
the due date.
miscarriage, the spontaneous expulsion of a
fetus before the twentieth week of pregnancy.
Complications of Pregnancy
Gestational hypertension, or high blood pressure
during pregnancy, may occur after the twentieth
week of pregnancy.
A severe form of this is preeclampsia.
Complications of Pregnancy
An ectopic pregnancy results when a zygote
implants not in the uterus but in the fallopian tube,
abdomen, ovary, or cervix.
This makes it impossible for the fetus to receive
nourishment and grow.
Childbirth
The birth of a baby takes place in three
steps: labor, delivery, and afterbirth.
Expectant parents must decide where the birth
will occur.
Childbirth
Birth occurs in three steps.
Step 1:
Labor
Step 2:
Delivery
Step 3:
Afterbirth
Childbirth
Step 1: Labor.
Muscle contractions of the uterus become regular,
stronger, and closer together.
This causes the cervix— the opening to the
uterus—to dilate, or widen.
Childbirth
Step 2: Delivery.
Once the cervix is fully dilated, the baby passes
through the birth canal and emerges from the
mother’s body.
The baby takes its first breath and cries to clear its
lungs of amniotic fluid.
Childbirth
Step 3: Afterbirth.
The placenta is still attached to the baby by the
umbilical cord.
Contractions, although weaker, will continue until
the placenta (now called the afterbirth) is pushed
from the mother’s body.
After You Read
Reviewing Facts and Vocabulary
1. Describe an embryo and a fetus.
An embryo is a cluster of cells that forms
between the third and eighth week of
pregnancy. This group of cells is called a
fetus after the eighth week.
After You Read
Reviewing Facts and Vocabulary
2. What is the difference between identical
and fraternal twins?
Identical twins form when one fertilized egg
splits into two different embryos. Fraternal
twins form when two eggs are fertilized by
two different sperm. These individuals are
not identical.
After You Read
Reviewing Facts and Vocabulary
3. What is the relationship between the
placenta and the umbilical cord?
The umbilical cord connects the fetus to the
placenta.