Slide 1

Ms. Kehoe 9 th Grade Health Slide 2 Fertilization Process Foreplay hugging, kissing, caressing to get the person sexually aroused - the male gets an erection and the female vagina lengthens, widens & moistens, Skene's Glands & Bartholin's Glands Ejaculation: when the man reaches orgasm he ejaculates up to 500 million sperm inside the woman, usually around the cervix. Within hours many sperm make their way into the womans body with only a few hundred make their way into the fallopian tubes. The female does not have an ejaculation, she may experience orgasm but not necessarily at the same time as the male. She does not release an egg cell when she has an orgasm but she may become moist. If no egg is present in the fallopian tubes the sperm will die in a few days. If an egg is present in the fallopian tubes fertilization may take place. Slide 3 Fertilization Process Slide 4 Egg (ovum) is released into the fallopian tube. Sperm surround the egg. Slide 5 Sperm surround the egg releasing enzymes to break down the protective cells surrounding the mature egg. Slide 6 Only the head of one sperm enters the egg. No other sperm may enter because the egg cells outer membrane changes sealing out all other sperm. Slide 7 The two nuclei (sperm and egg cell) combine. Slide 8 The Two Nuclei Combine- 23 chromosomes from the male and 23 chromosomes from the woman Combine to form 23 pair or 46 chromosomes. Slide 9 Chromosomes Are thread-like structures in the nucleus of the cell that are made up of genes, Carries of hereditary traits, That determine which traits we inherit from out parents Slide 10 Sex of the Child Egg has a X chromosome pattern gene Sperm has a X or Y chromosome pattern gene XX chromosome pattern will be a girl XY chromosome pattern will be a boy Current theory is the sperm determines the sex of the child Slide 11 Development of a Human Being Slide 12 Within the first 36 hours the fertilized egg (zygote) cleaves (divides) forming two identical connected cells. Slide 13 4 Cells, Slide 14 8 cells, 16 cells,... Slide 15 ..until a hollow ball of cells is formed (blastula) Slide 16 Fraternal Twins: 2 eggs are released and fertilized. Identical Twins: 1 egg & 1 sperm divide into two separate morula. Slide 17 Once the blastula is implanted in the uterus (1 to 2 weeks) it is called an embryo. Slide 18 Development of a Human Within the first 36 hours the fertilized egg (zygote) cleaves (divides) forming two identical connected cells, 4 cells, 8 cells, 16 cells, until a hollow ball of cells is formed (blastula). Once the blastula is implanted in the uterus (1 to 2 weeks) it is called an embryo. This cleaving process will continue for the next 9 months. Slide 19 Super Structures Slide 20 Yolk: looks like the yellow part in an egg it provides nourishment for the embryo until the placenta is developed. Slide 21 Stalk: Holds the embryo to the uterine wall and becomes the umbilical cord. Slide 22 Umbilical Cord rope like structure width of your thumb, 14 to 30 inches long, & all nourishment and waste pass through this structure. It has no nerves so it causes no pain when it is cut. Slide 23 Umbilical Cord: Slide 24 Placenta: Network of blood vessels and other tissues which is attached to the wall of the uterus. It serves as transition place for all nourishment & waste. The blood of the mother and the fetus never mix. Slide 25 Placenta Cont.: The blood vessels grow side by side and are not directly connected. Blood type of the fetus can be different from that of the mother. Slide 26 Development of a Human Being Terms: Slide 27 Amnionic Sac: Fluid filled membrane that surrounds the growing embryo and fetus. Called the bag of water. Functions: controls temperature, provides room to grow and move, and protects the fetus from injury. Slide 28 Slide 29 Zygote: a fertilized egg (ovum) Slide 30 Blastula: A hollow ball of cells that divides as it travels to the uterus. It gets its nourishment from the blood enriched walls of the womb. Slide 31 Embryo: Implanted blastocyst in the uterus. Slide 32 Fetus: From the 10 th week until the birth. Looks like a tiny human being.