1. Involuntary muscle contractions begin
2. Blood pressure, heart rate, and breathing are at their highest rates, with a rapid intake of oxygen
3. Muscles in the feet spasm
4. Sudden, forceful release of sexual tension
5. In women, the muscles of the vagina contract
6. Uterus also undergoes rhythmic contractions
7. In men, rhythmic contractions of the muscles at the base of the penis result in the ejaculation of semen
8. A rash, or "sex flush" may appear over the entire body