Health 12/18/11 Today’s objective: Students will learn about the process of fertilization and pregnancy through a power point presentation by taking notes and viewing pictures. Warm-up: Teen Pregnancy is…

Fertilization & Pregnancy

Menstruation & Ovulation The menstrual cycle occurs in most females from puberty to menopause. The menstrual cycle is a monthly series of hormone controlled changes that prepare the uterine lining for pregnancy. Increasing levels of two hormones (follicle stimulating hormone (FSH) and luteinizing hormone (LH) cause maturation and release of an egg.

The release of an egg from a follicle in the ovary is called ovulation. Ovulation usually occurs on the 14 th day of the cycle-the menstrual cycle varies from female to female but the average is 28 days. The day before ovulation and several days after are the most fertile time for a female. Why? There is an egg release and if sperm is introduced the egg may become fertilized. If pregnancy does not occur then the female will have her period in about 2 weeks and it usually lasts 3 to 7 days.

If the female gets pregnant……..

Fertilization

Fertilization & Implantation Once a sperm penetrates an egg, a chemical change occurs preventing other sperm from entering the egg. The genetic material (DNA) from the egg and sperm combine and form a zygote. The zygote travels down the woman’s fallopian tube toward the uterus-this takes 3 to 5 days. As the zygotes moves down it divides over and over again forming a ball of cells which eventually becomes a embryo. These cells become embedded in the uterine wall-this is called implantation. Once implantation occurs the female is considered pregnant.

Vocabulary Embryo: a developing human, from fertilization through the first 8 weeks of development Placenta: a blood vessel-rich organ that forms in a mother’s uterus and provides nutrients and oxygen to and removes wastes from the developing human Fetus: a developing human, from the start of the ninth week of pregnancy until delivery Prenatal care: the health care provided for a woman during her pregnancy Gestation: the length of time a female is pregnant

Trimesters Pregnancy is broken up into 3 trimesters. First Trimester: Up to 13 weeks Second Trimester: 14 to 27 weeks Third Trimester: 28 to 41 weeks

4 weeks Gestation

9 weeks

12 Weeks

By 12 weeks…. The most dramatic development this week: reflexes. The baby's fingers will soon begin to open and close, toes will curl, eye muscles will clench, and the mouth will make sucking movements. The intestines, which have grown so fast that they protrude into the umbilical cord, will start to move into his abdominal cavity about now, and his kidneys will begin excreting urine into the bladder. Meanwhile, nerve cells are multiplying rapidly, and in the baby's brain, synapses are forming furiously. The face looks unquestionably human: The eyes have moved from the sides to the front of his head, and ears are right where they should be. From crown to rump, your baby-to-be is just over 2 inches long-about the size of a lime and weighs half an ounce.

Second Trimester-14 Weeks

By 14 Weeks The baby can now squint, frown, grimace, pee, and possibly suck the thumb! Thanks to brain impulses, facial muscles are getting a workout as his tiny features form one expression after another. Kidneys are producing urine, which release into the amniotic fluid around the baby— a process it will keep up until birth. The baby's stretching out. From head to bottom, the baby measures 3 1/2 inches about the size of a lemon — and weighs 1 1/2 ounces.

24 Weeks

28 Weeks

By this week, The baby weighs two and a quarter pounds (like a Chinese Cabbage) and measures 14.8 inches from the top of the head to the heels. Baby can blink, and has eye lashes. With the eyesight developing, the baby may be able to see the light that filters in through the womb. Baby is also developing billions of neurons in the brain and adding more body fat in preparation for life in the outside world.

Delivery-40 to 41 weeks of average

Stages of Childbirth The first stage begins with the onset of contractions that cause progressive changes in your cervix and ends when your cervix is fully dilated to 10 cm. This stage is divided into two phases: early (or latent) and active labor. During early labor, your cervix gradually effaces (thins out) and dilates (opens). During active labor, your cervix begins to dilate more rapidly and contractions are longer, stronger, and closer together. People often refer to the last part of active labor as "transition."

The second stage of labor begins once you're fully dilated and ends with the birth of your baby. This is sometimes referred to as the "pushing" stage. The third and final stage begins right after the birth of your baby and ends with the separation and subsequent delivery of the placenta. Every pregnancy is different, and there's wide variation in the length of labor. For first-time moms who are at least 37 weeks along, labor often takes between ten and 20 hours. For some women, though, it lasts much longer, while for others it's over much sooner. Labor generally progresses more quickly for women who've already given birth vaginally.

Breastfeeding