Excitement Phase: The excitement phase refers to the first stage in the sexual response cycle where there's an initiation or increase in physical arousal such as increased heart rate, breathing, and blood pressure.
Plateau Phase: The plateau phase is part two of four stages within the human sexual response cycle where changes initiated in excitement phase are intensified. Arousal continues to increase towards a peak.
Orgasm Phase: This is typically considered as climax or peak of sexual activity where involuntary muscle contractions occur along with release of sexual tension.