Not exact matches
Unlike emergency contraception, which acts before implantation
of the
fertilized egg, RU486 is an antiprogestin, which
causes the uterine lining to shed after implantation.
This consequently
causes the release
of more than one
egg increasing your chances
of having more than one
of them
fertilized.
It happens six to 12 days after conception, when a
fertilized egg burrows deep into the lining
of your uterus,
causing a bit
of mild irritation.
This is
caused when the
fertilized egg attaches to the wall
of the uterus.
Human multiple births can occur either naturally (the woman ovulates multiple
eggs or the
fertilized egg splits into two) or as the result
of infertility treatments such as IVF (several embryos are often transferred to compensate for lower quality) or fertility drugs (which can
cause multiple
eggs to mature in one ovulatory cycle).
One
of the earliest signs
of pregnancy is light spotting which is
caused by the
fertilized egg attaching itself to the uterus wall after conception.
The film depicts several sperm attempting to
fertilize the
egg, «zooms in» on one sperm's tail to show how the dynein proteins move in sync to
cause the tail to bend and flex, and ends with the sperm's successful journey into the
egg and the initiation
of cell division that will ultimately create a new organism.
By manipulating a specific gene in a mouse blastocyst — the structure that develops from a
fertilized egg but is not yet an actual embryo — scientists with the University
of Florida's McKnight Brain Institute and the Harvard Stem Cell Institute
caused cells destined to build an embryo to instead change direction and build the cell mass that leads to the placenta.
Such as, the pituitary which is responsible for regulating female reproductive hormones such as LH (luteinizing hormone, which
causes ovulation), FSH (follicle stimulating hormone, which matures the
eggs in the ovaries), progesterone (which
causes the endometrium to mature so that it can support implantation
of the
fertilized egg), and estrogen.
The research, conducted in Benin City in southern Nigeria, suggests toxic metals and other contaminants in e-waste are reducing levels
of key hormones in men in developing countries and could contribute to reduced sperm levels, and
cause damage to the sperm's DNA, stability and ability to
fertilize eggs.