HLT 200: Human Sexuality Chapter 3

1. Human Sexuality
Chapter 3

2. Biology, Psychology,
And Human Sexual Responding
•Why do humans become sexually aroused? (p.
76)
–Psychological reasons
•The impulse toward reproduction
•Feeling pleasure
•Giving pleasure
•Expressing feelings of closeness and love
•Relieving stress
•Feeling valued by another person
•Expressing how much another person is vauled
•Feeling more or less dominant or submissive
•And etc.

3. EPOR Model
•EPOR model – Masters and Johnson’s approach
to explaining the process of human sexual
response, encompassing 4 arbitrarily divided
phases (p. 77)
–1. excitement
–2. plateau
–3. orgasm
–4. resolution
•Simply put EPOR model explains how our bodies
change during sexual stimulation (p. 77)
•It is a seamless process (p.77)

4. EPOR Model
SEE Figures 3.2 and 3.3
•Excitement – the first phase, in which the first physical
changes of sexual arousal occur (pp. 78-80)
–Early physical responses can occur to any type of pleasurable
sexual
•Kissing , Touching, Sexual fantasy and etc.
–What triggers sexual arousing
•Sexual history and Cultural beliefs
–Signs of Excitement
•WOMEN and MEN – breasts, nipples and areolas enlarge slightly
•WOMEN and MEN – Vasocongestion – the swelling of erectile tissues
due to increased due to blood flow during sexual arousal causing
them to expand and stiffen in both sexes
•WOMEN – vaginal lubrication; clitoris begins to become erect along its
full length; shaft of the clitoris increase in size; labia minora swells and
may separate from around the opening to the vagina
•WOMEN – internally, the uterus engorges with blood, enlarges, and
moves slightly upward and it may exhibit fibrillations; vagina begins to
change shape, becoming longer and widening
•MEN – erection of the penis; scrotal skin tightens; testicles begin to
rise up toward the underside of the penis; testicles enlarge somewhat

5. EPOR Model
SEE Figures 3.4, 3.4, 3.5 and 3.6
•Plateau – the second phase, during which sexual arousal levels off
(reaches plateau) and remains at an elevated level of excitement (pp.
80-81)
•Signs of Plateau
–WOMEN and MEN – all erectile tissues are now fully engorged with blood
–WOMEN and MEN – respiration, heart rate, blood pressure, and muscle
tension are all at high levels as orgasm approaches
–WOMEN – nipples maintain their erect state, but the areolas continue to
become larger
–WOMEN – walls of the outer one-third of the vagina become engorged with
blood and thicken, reducing the size of the vaginal opening
–WOMEN – tenting occurs, which is the widening of the inner two-thirds of the
vagina during sexual arousal
–WOMEN – clitoris engorge with blood, straightening out along its length
–WOMEN – libia minora deepen in color as they become increasingly engorged
with blood
•This is indication that orgasm is approaching
–MEN – penis becomes fully erect; the corona enlarges further; the Cowper’s
glands secrete enough pre-ejaculate fluid that is can be seen and felt at the
opening of the urethra; scrotal skin is tight; testicles are pulled up
•The testicles pulled up very closely against the body at the underside of the penis is an
indication that orgasm is approaching

6. EPOR Model
SEE Figures 3.7 and 3.8
•Orgasm – the third stage during which sexual
excitement and pleasure reach a climax (pp. 81-82)
•Sings of Orgasm
–WOMEN and MEN – respiration increases dramatically;
pulse and blood pressure continue to rise; a loss of control
over voluntary muscles; muscles in the pelvic area
contract rhythmically;
–WOMEN – anus, uterus, muscles of the pelvic floor, and
walls of the outer third of the vagina all contract at
interval of 0.8 second during orgasm
–MEN – anus, prostate gland, urethra, and muscles at the
base of the penis contract at intervals of 0.8 second during
orgasm – ejaculation

7. EPOR Model
SEE Figures 3.11 and 3.12
•Resolution – the fourth stage, during which sexual
structures return to their unaroused state (p. 88)
–WOMEN and MEN – heart rate, blood pressure, and muscle
tension drop quickly
–WOMEN and MEN – usually feel relaxed, warm, content, and
sleepy
–WOMEN – blood flows back out of erectile tissue throughout
the genitals and breasts so almost everything returns back to
the unaroused state
•except the cervix, which widens slightly to facilitate the passage of
semen into the uterus
–It narrows again about a half-hour after orgasm
–MEN – blood flows back out of erectile tissue throughout the
genitals and the nipple area
•Refractory period – a period of time following orgasm when a person
is physically unable to become aroused to additional orgasm
–It may last from a few minutes to 24 hours

8. Male Ejaculation
•MEN – ejaculation occurs in 2 stages (pp. 82-83)
–1
st
Stage
•Emission is the buildup of sperm and semen in the urethral
bulb just prior to being expelled through the urethra
•Ejaculatory inevitability is the sensation produced during the
emission phase of ejaculation that expulsion of semen is
imminent, reflexive, and cannot be stopped; often referred
to as the “point of no return”
–2
nd
Stage
•Expulsion is the contraction of pelvic muscles that force
semen through the urethra and our of the body through the
penis
–Afterglow – the emotional and physical feeling of
satisfaction, relaxation, and intimacy that follows the
act of making love
•It may be facilitated by an increase in the hormone oxytocin

9. Female Ejaculation
•For female ejaculation, 2 questions are asked (p.
86-87)
–1. Do some women truly ejaculate upon orgasm
–2. If so, what does the female ejaculate consist of
–Question 1
•Beginning in the 1970s, reports began appearing of women who
claimed to ejaculate upon orgasm
•Female ejaculation has been the subject of much debate
–Question 2
•Some claim it’s identical to urine
–If it is urine then the intense muscular activity during orgasm can lead to
some slight incontinence in some women
•Some claim it’s more akin to semen
–Some studies have found that it actually resembles male prostatic fluid
in chemical composition
–NOTE – not all women ejaculate, and most women who do
not do not particularly care about it