Genetics, Prenatal Development, and Birth Essay Example

amniotic sac collecting fluid from around the baby. (PG. 61-65) D. During a woman’s reproductive years, each ovary nourishes several hundred egg cells, mature and become ready for fertilization. An egg cell (ovum) matures in approximately every 28 days. When a menstrual cycle comes only the one that has matured is released. At fertilization, 23 chromosomes from each, the mother and father are joined to produce a combination.

So, an egg is matured, emitted from the ovary and then moves down the fallopian tube. If the egg fertilize, it will form a zygote that travels to the uterus and implant in the inner lining while continuing to develop. (PG. 84-85) E. The major events in each stage of prenatal development are the germinal, embryonic, and fetal. The germinal stage consist of when conception is starts to 2 weeks which the zygote implants itself in the mother’s uterine lining. The embryonic stage begins after the second seek but begins through and out the 3rd through the last 8th week.

This point the blastocyst form three cell layers in the embryo, also in this stage can occur loss of pregnancy before a baby is born alive. The last stage which is fetal stage, is period of week 9 to birth (38 to 40 weeks). During this time fetus grow rapidly in size and weight. Around 9 to 12 weeks, the baby arm movements begin, first reflexes and the sex organs develop enough for examination of the fetus. By 17 to 20 weeks mother begin to feel movements. (PG. 85-89) F. Teratogen is which may cause birth defects.

The use of any drugs, tobacco substance get in the mother’s bloodstream and

crosses the placenta then damage the developing fetus by polluting in the mother’s tissue causing harmful chemicals being transmitted to the fetus. Infectious virus and sexually transmitted disease can also reach the fetus that’s in the mother. (PG. 90) G. The three stages of birth are dilation, delivery, afterbirth. One complication during birth involves the position of the fetus. The optimal fetal position is head down, that allows the head to move down the canal first and minimize risk to mother and baby.

But the baby may be in a breech position, buttocks or the feet are the lowest in the uterus which is malpresentation. Most malpresentation pregnancy will occur to have a cesarean section (C-section) delivery. Another one is fetal distress, the fetus experience lack of oxygen, change in heart rate, or change in respiration. A fetus can withstand brief oxygen deprivation with no ill effects, and when it’s oxygen decrease for more of a few minutes can lead to permanent brain damage. (PG. 101-103)