Human Sexual Response Cycle

1
Human Sexual Response Cycle
2
Models of Human Sexual Response

• (1966) Masters Johnson
• Four-Phase Model
• Excitement
• Plateau
• Orgasm or climax
• Resolution

• Kaplan (1974)
• Three-Phase Model
• Sexual desire
• Vasocongestion
• Orgasmic release

3
Activating the ResponseComponents of Sexual
Arousal

• External Stimuli
• Peripheral Arousal System
• Cues from skin, touch stimulation of genitals,
  nervous system, and senses

• Internal Stimuli
• Central Arousal System
• Emotional pleasure centers of the brain
• When the mind ascribes sexual meaning, genital
  physiological arousal can be automatic

4
Gender Differences and Arousal

• Woman-Romantic
• Men-Physical

5
Female Sexual Response

• Excitement Phase
• Vasocongestion and other changes in the genital
  region
• Vagina become lubricated with an alkaline fluid
• Plateau Phase
• Increased changes in the vagina
• Orgasmic platform is created
• Breasts may become swollen and nipples may become
  erect
• Increase heart rate, respiration, and blood
  pressure
• Orgasm
• Heart rate, respiration, and blood pressure reach
  peak
• Several muscle contractions of vagina and anal
  area
• Pleasurable feelings throughout the body
• Resolution
• Body returns to unexcited state
• Drowsiness may occur as muscles relax

6
Female Sexual Response
7
Male Sexual Response

• Excitement Phase
• Vasocongestion leads to erection of the penis
• Muscular tension increases throughout the body
• Plateau Phase
• Testes may increase in size by 50 percent
• Cowpers glands often secrete fluid
• Glans of the penis becomes swollen
• Increased heart rate, respiration, and blood
  pressure
• Orgasm
• Ejaculatory inevitability distinct inner
  sensation
• Strong muscle contractions at base of penis and
  anal area
• Semen is expelled
• Pleasurable feelings throughout the body
• Resolution
• Body returns to unexcited state, process may take
  two hours
• Drowsiness and relaxation (Refractory period
  begins)

8
Male Sexual Response
9
Organizing Activating Effects of Hormones

• Organizing Effects
• Control development of sex glands, external
  genitals, and nervous system in the fetus
• Activating Effects
• May activate or deactivate sexual behavior
• Central arousal system is more influenced by
  hormones than the peripheral arousal system
• Testosterone acts as an activator for sexual
  desire in both men and women
• Male hormone (androgen) produced by the ovaries
  in females and by the testes in males
• Males have higher levels of testosterone than
  females, but females are more sensitive to
  testosterone

10
Effects of Aging on Sexual Response

• Females
• Thinning of vaginal lining
• Reduced lubrication
• Cramping with orgasm
• Longer time for arousal to occur
• Longer time to reach orgasm
• Fewer muscular contractions with orgasm
• While the frequency of sexual activity decreases,
  men and women remain sexually responsive and
  continue to experience sexual pleasure as they
  age.

• Males
• Takes longer to achieve a full erection
• Reduction in amount of semen
• Longer time to reach orgasm
• Reduced strength of orgasmic contractions
• Lengthening of refractory period