Fetal Development

Challenges the sperm encounter in reaching the egg a.20% defective b.25% die immediately c.Acid environment of the female body d.Immune system attack them e.½ go to the wrong fallopian tube f.Get stuck in the cell wall lining the fallopian tube g.Lose sense of direction

How many sperm reach the egg? 50 Fertilization: The joining of the egg and sperm cell that takes place in the upper part of the fallopian tube What keeps more than one sperm from entering the egg? A biochemical change in the egg creates a barrier

Zygote -what the egg is called from fertilization until it implants in the uterus Embryo -what the egg is called from implantation between the 3rd and 8 th weeks of pregnancy Fetus -what the egg is called from the 9 th week until it is born.

Placenta A membrane organ that nourishes the embryo and fetus. Functions: Transport oxygen Transport nutrients Remove waste

Umbilical cord Attaches the baby to the placenta when it falls off you are left with a belly button

Amniotic Sac A protective membrane that surrounds the embryo and fetus Helps maintain even temperature Reduces trauma Allow baby to move Prevents uterine wall from pushing in on fetus

Stillbirth vs Miscarriage Miscarriage is a loss of a pregnancy before 24 weeks, usually occurs in the first 12 weeks. Majority are due to chromosome, genetic or structural problems Stillbirth baby was developing but dies after 25 weeks

First Trimester ▫0-2 weeks: zygote may float freely in the uterus for 48 hrs before implanting. ▫3-8 weeks: embryo is about 1 inch long at 8 weeks. The mouth, nostrils, hands, fingers, feet, and toes begin to form ▫9-14 weeks: Fetus develops a human profile. Sex organs, eyelids, finger nails, and toe nails. By week 12 fetus makes crying motions but has no sound

Second Trimester ▫ weeks: fetus can blink it eyes. Body begins to grow. Eyebrows and eyelashes develop. Fetus can grasp and kick and becomes more active. ▫21-28 weeks: fetus can hear conversations and has regular cycle of waking and sleeping. Fetus is 12 inches long and weight a little over 1 pound.

Third Trimester ▫29-40: fetus uses all five senses and begins to pass water from the bladder. Around 38 weeks baby weighs about 6 to 9 pounds

Premature Baby born before being fully developed A baby born after 36 weeks stands the best chance of survival