fertilization Union of a sperm and egg; occurs in a fallopian tube.
fetus Stage of a developing baby between the end of the 8thweek after fertilization and
birth.
implantation Process in which the ball of cells that will become an embryo embeds in the
lining of the uterus.
infancy First year of life after birth.
placenta Spongy mass of blood vessels from the mother and fetus that allows substances
to pass back and forth between the mother’s blood and the fetus’s blood.
puberty Stage of life when a child becomes sexually mature.
umbilical cord Tube containing blood vessels that connects a fetus to the placenta.
zygote Cell that forms when a sperm and egg unite; the first cell of a new organism.
Points to Consider
- By early adulthood, most people have become sexually active. Sexual activity puts
people at risk of certain diseases. Do you know what the diseases are? Do you know
how they can be prevented? What are other ways of keeping the reproductive system
healthy?
22.4 Lesson 22.4: Reproductive System Health
Lesson Objectives
- Describe common sexually transmitted diseases.
- Identify other reproductive system disorders.
- List ways to keep the reproductive system healthy.
Check Your Understanding
- What is a pathogen?
- What types of organisms can cause disease?
- What is cancer?