Related to Precordial pain: costochondritis, Pulsus paradoxus, retrosternal pain. unpleasant or hurtful sensation resulting from stimulation of nerve endings. The stimulus is carried by nerve fibers to the spinal cord and then to the brain, where the nerve impulse is interpreted as pain.
Full transcript. The sperm race begins Ejaculation The race resumes A man's penis releases around 20 million sperm into the woman's vagina, where they then begin their journey.Around 2,000 sperm then travel up to the top of the vagina and through the cervix.aiting for the egg When the sperm are awakened they travel to egg and the race resumes. Time to be born The mother's Muscles contract to push the baby out. The amnion sack breaks ('water' breaks). The head moves into the entrance of the vagina.
The Sperm's Long Journey A man may ejaculate 40 million to 150 million sperm, which start swimming upstream toward the fallopian tubes on their mission to fertilize an egg. Fast-swimming sperm can reach the egg in a half an hour, while others may take days.