Egg ProductionStreaming Video - 2013
Key female reproductive organs are the uterus, ovaries, fallopian tubes, and vagina. The ovary contains developing eggs called oocytes. At birth, all the eggs that a female will produce are inside the ovaries in an undeveloped form. Approximately once a month starting around age twelve, hormonal messages from the brain cause an egg to develop in the ovaries. Several hormones regulate the reproductive cycle. These include estrogen, progesterone, FSH (follicle stimulating hormone), and LH (luteinizing hormone). A follicle is an egg surrounded by cells that release hormones. FSH prepares an egg for fertilization by causing it to begin dividing its genetic material called chromosomes.The follicle releases estrogen, which prepares the uterine lining to receive a fertilized egg. Increased estrogen levels in the bloodstream cause the pituitary gland to stop releasing FSH and to start releasing LH. LH causes the follicle to enlarge rapidly and release its egg in a process called ovulation. Once the egg is out of the follicle, the follicle begins secreting progesterone, which also helps to prepare the uterine lining for the fertilized egg. Fimbriae, small waving structures at the entrance to a fallopian tube, sweep the egg into the fallopian tube toward the uterus. As the egg moves toward the uterus, a sperm cell may fertilize it, usually in the fallopian tube. If this happens, the fertilized egg is transported to the uterus, and it implants itself in the uterine wall, where it receives nourishment. In the ovary, the remaining follicle cells produce progesterone, which helps the fertilized egg develop into an embryo. If an egg is not fertilized within 24 hours after its release from the ovary, it stops developing and dissolves. The body stops releasing the hormones that prepare the uterus for implantation and the uterus sheds its lining over a period of four to five days in a process called menstruation.
Publisher: New York, N.Y. : Films Media Group, , c2010
Characteristics: 1 streaming video file (4 min.) :,sd., col