1 Transmission: neurons transmit these signals to pain-processing structures of the spinal cord and brain. 2  Modulation: the signals can be amplified or dampened at various points in the pathway to facilitate or inhibit transmission, thereby enhancing or reducing the sensation of pain.
The sperm usually fertilizes the egg in the Fallopian tubes. Then, the fertilized egg moves down to the uterus where it implants, causing pregnancy. The segment of the Fallopian Tube where fertilization commonly occurs is the ampulla..
Fertilization and Implantation Symptoms. When the egg is ready for fertilization, it travels from the ovaries into the fallopian tube, where it will fertilize with the sperm if you have had unprotected sex in your fertile period of your cycle. This fertilized egg travels to the uterus and plants itself on the wall. This is called implantation. Implantation is the implanting of the fertilized egg or embryo or even called a blastocyst on to the uterine wall. It takes place about 2-3 weeks after ovulation. Soon after fertilization, symptoms also occur about 2-3 weeks after ovulation.