2. Prenatal development refers
to the process in which a baby
develops from a single cell
after conception into an
embryo and later a fetus.
3. Fertilization
• When semen is deposited in the vagina
,the spermatozoa travel through
the cervix and body of the uterus and
into the Fallopian tubes. Fertilization of
the ovum (egg cell) usually takes place
in the Fallopian tube. Many sperm must
cooperate to penetrate the thick
protective shell-like barrier that
surrounds the ovum. The first sperm
that penetrates fully into the egg
donates its genetic material (DNA).
4. Embryonic period
• The embryonic period in humans begins
at fertilization (penetration of the egg by the sperm)
and continues until the end of the 10th week of
gestation (8th week by embryonic age).
• The embryo spends the next few days traveling
down the Fallopian tube. It starts out as a single cell
zygote and then divides several times to form a ball
of cells called a morula. Further cellular division is
accompanied by the formation of a small cavity
between the cells. This stage is called a blastocyst.
Up to this point there is no growth in the overall size
of the embryo, as it is confined within a glycoprotein
shell, known as the zona pellucida. Instead, each
division produces successively smaller cells.
5.
6. • Period of the Ovum (zygote)
–0-2 Weeks
–Conception / Fertilization
–Cell Multiplication – single cell
divides into 2
4
8…
–Implantation – cells attach to wall
of uterus
–About the size of a pin head.
7.
8. • Period of the Embryo
– 2 – 8 weeks
– Formation of most major organs and
bones;
– Formation of placenta, amniotic fluid
and umbilical cord; nourishment
begins to pass
– Heart begins to beat
– Amniotic fluid acts as a “shock
absorber” and is replaced every 3
hours.
9. Lightening: Baby moves lower into
pelvis in anticipation of delivery;
Fetus can suck its thumb, cough
sneeze, yawn, & hick-up.
10.
11.
12.
13.
14. “If we accept that a mother
can kill even her own child, how
can we tell other people to not
kill each other? Any country
that accepts abortion is not
teaching its people to love, but
to use any violence to get what
they want.”
