2/07 Pregnancy

It is not enough to know the parts of the reproductive system. Relevance It is not enough to know the parts of the reproductive system. Its important to understand how the system works. For some, this will be review. Try to see it with fresh eyes.

Concepts in this lesson The components of a cell The process of conception The process of gender determination How multiple births occur Pregnancy problems

Components of a typical cell

Sex cells: ovum and sperm

Fertilization

Implantation

Gender determination

Multiple births: identical and fraternal

Pregnancy

Prenatal development: first 3 months 1st month: Blood begins circulating, Brain is beginning to form (though it does not work yet) 3rd month: male and female look different. Fingers, toes, and fingernails form. Head is half the size it will be at birth. 2nd month: arms, legs, and internal organs begin forming. Genitals start to form, but male and female still look alike. Tail disappears.

6th month: brain starts working, eyes open, ears begin to work. Second three months 6th month: brain starts working, eyes open, ears begin to work. 4th month: muscles move. Skin is transparent. Sweat glands, eyebrows, and eyelashes form. 5th month: hair forms, hiccups begin and other movement can be felt, heartbeat can be heard.

Last three months 7th month: adds body fat, moves regularly, responds to sound, sometimes awake, sometimes asleep. 8th month: less active, but still growing rapidly. Nails and bones begin to harden. 9th month: lungs and organs finish maturing. Brain and reproductive system won’t finish maturing for years.

Pregnancy problems: “miscarriage” Definition: a pregnancy ending much too soon, before the embryo or fetus is able to live outside the uterus. Some possible causes for miscarriage or birth defects: chromosomal abnormality (gene mutation), mother’s or father’s consumption of drugs (alcohol and tobacco included), mother’s illness (including some STDs), radiation or environmental pollution, mother’s age (healthiest range is 20s-30s), father’s age, birth trauma, baby’s illness.

Fact: there is a high rate of birth defects, miscarriages, premature birth, and low birth weight in babies born to teens. Possible causes: little or no prenatal care, poor nutrition, consumption of alcohol, cigarettes, and other drugs.

Where can I get more answers about pregnancy? www.marchofdimes.com www.sexetc.com www.teenwire.com School nurse, family doctor, OB/GYN doctor, an adult family member.