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..
A sperm meeting an egg. Fertilization, also called conception, happens when a sperm cell combines with an egg cell, usually in the uterus. Once the first sperm enters the egg, the egg's cell membrane solidifies, to prevent multiple sperm from entering. As the egg cell begins to divide, it is called a zygote. Typically, fertilization occurs in the fallopian tubes.