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 occurs during the process of laying an egg. As an ovum moves down her oviduct and begins to form into an egg, the duck hen mixes in a little sperm from her sperm storage. The eggshell then forms around the ovum, yolk and sperm, and creates the egg we recognize. She will do this every day up to two weeks, laying an egg each day. Once the entire clutch of eggs has been laid, the new mother will begin to incubate them, until they hatch. During this time, you can check to see if the eggs have been fertilized with a process called candling..