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..
Under normal circumstances, fertilization occurs in one of the Fallopian tubes, then the fertilized egg begins to make its way to the uterus. By about the fifth day after conception, the embryo finally reaches the uterus, where it implants itself in the endometrium, or uterine lining.