Human Growth and Development Grade 7 The Life of the Egg The Life of the Sperm Fertilization Pregnancy and Fetal Development Labour and Delivery Developed by Saint John Area Public Health Sexual Health Program 2015. Created for teaching purposes only .Do not reproduce without permission

Female Reproductive System

The Life of the Egg 300,000-400,000 eggs stored in the ovaries 300-500 eggs released during fertile years- 12-52 Average Menstrual cycle 23-35 days First half of cycle- FSH is released - causing the egg to “mature” As the egg matures – estrogen is increased – prepares the “bed” (endometrium) for the egg On day 14- LH causes the egg to be released – (Ovulation)

Egg lives for 1 day only- most fertile time Progesterone also increases to prepare the (womb) uterus and prevent it from contracting The rise in Hormones prevents the ovaries from releasing any more eggs If sperm does not fertilize the egg—stop production---start over Hormones drop and the lining is shed about 14 days later- Menses begins.

Male Reproductive System

The Life of the Sperm Sperm production starts in the scrotum (thermostat) Scrotum holds the 2 testes (gonads) which secrete the sex hormone –testosterone and make sperm– ½ billion made every day It takes 70 days for one sperm to mature. Sperm have a head (DNA) and a tail (swim) Once the sperm is made in the testes- other parts of the RS are responsible for the Semen. Semen is the pool that the sperm swim in.

The Life of the Sperm Immature sperm move from the testes to the epidydmis (Learn to swim)- this process takes 3 weeks. When the epidydymis is full- wet dream may happen Move to the vas deferens (moves sperm along) Sperm need to be nourished along the way: Seminal Vesicle- Sugar Prostate- Protein Cowpers gland- Oil/cleanses tube of urine Penis - Spongy tissue Valve closes urinary system- during sexual arousal 200-500 million sperm released at once

Race to the Egg

Fertilization when a sperm cell and an egg join together fertilization (conception) occurs the sex of the baby and genetic make-up has been determined the fertilized egg then starts to divide rapidly into many cells about three days after conception, the egg passes through the fallopian tube into the uterus where it attaches to the uterine wall the placenta begins to form - will nourish the baby during pregnancy

4 weeks gestation structures that eventually form the face and neck are becoming evident the heart and blood vessels continue to develop the lungs, stomach, and liver start to develop a pregnancy test may now be positive

8 weeks the fetus is about the size of a grape - almost an inch in length eyelids and ears are forming the tip of the nose is visible the arms and legs are well formed with the fingers and toes growing longer and more distinct.

12 weeks - sex organs may be seen - the fetus measures about 2 inches and is starting to move on its own - sex organs may be seen - heart rate may be heard by your doctor

16 weeks fetus is about 4.3 to 4.6 inches, weighs about 2.8 ounces baby can blink his eyes heart and blood vessels are fully formed fingers and toes should have fingerprints the top of your uterus should be felt about three inches below your belly button

20 weeks weighs about 9 ounces and is about six inches long can suck a thumb, yawn, stretch, and make faces mom can feel her baby move which is called "quickening." - uterus should be at the level of the belly button

Ultrasound Time An ultrasound is generally performed for all pregnant women at 20 weeks of gestation - doctor will check to make sure the placenta is healthy and attached normally and that your baby is growing well - heartbeat can be seen - body, arm, and leg movements can also be seen - baby’s gender can usually be determined at 20 weeks 2D ultrasound (inset) contrasted with a 4D ultrasound, both at 20 weeks

24 weeks weighs about 1.4 pounds now can respond to sounds by moving around or with an increased heart rate may develop hiccups- jerking motion to mom inner ear is fully developed, may be able to sense being upside down in the womb T

28 weeks weighs about 2 pounds 6 ounces changes position frequently increased survival rate if your baby is born early (premature)

32 weeks weighs almost 4 pounds often moving skin has less wrinkles as a layer of fat starts to form under the skin will gain up to half its birth weight between now and delivery mom may leak some colostrum from her breasts, a yellowish fluid that is produced before breastmilk

36 weeks weighs around 5.5 pounds, about 12.5 inches brain has been developing rapidly lungs are nearly fully developed head is usually positioned downward into the pelvis for delivery pregnancy is considered 'at term' once 37 weeks has occurred and baby is ready to be born!

39-40 Weeks At birth, the average baby is more than 20.5 inches long from head to toe and weighs approximately 7.5 pounds, but babies vary widely in size at this stage. All organs are fully developed and baby is ready to begin life outside of the uterus.

Stages of Labour and Delivery

3 D Labour and Delivery Video (This is a link to an excellent 2 minute 3 D animated video depicting the stages of labour and birth) www.babycenter.ca/video/labour-and-birth/labor-birth/

References http://www.medicinenet.com/fetal_development_pictures_slideshow/article.htm © 1996-2015 MedicineNet. All rights reserved. http://www.babycenter.ca/video/labour-and-birth/labor-birth/