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Physiology of Female
Sexuality
For women, the choice of a sexual partner and courtship underline the importance of the
social context in which female sexuality takes place. Emotional closeness is, more often
than for men, a prerequisite for sexual activity.
The stages of the sexual response cycle are arousal,
orgasm and resolution - arousal may be considered as having an initial excitement phase
followed by a plateau phase. In the excitement phase an increase in the blood flow to the
genitals leads to labial and vaginal engorgement and lubrication. The speed and intensity
of arousal varies greatly.
The plateau phase describes a more or less steady state
of high arousal which is still not so intense as to trigger orgasm. In this phase there is
retraction of the clitoral hood. The anatomy of the clitoris has recently been shown (in
dissection studies of younger women) to be more extensive than previously thought.
With further stimulation and vascular engorgement to the
clitoris a sense of orgasmic inevitability (similar to the male experience of
inevitability) occurs and is followed by orgasm. Orgasm is an intense, pleasurable
sensation in the genital region and is accompanied by rhythmic contractions of the vaginal
wall, Fallopian tubes and pubo-coccygeus muscle (a ‘sling’ of muscle in the
floor of the pelvis), with widespread changes elsewhere. A skin flush from dilation of
blood vessels occurs indicating involvement of the autonomic nervous system throughout the
body.
The difference between the male and female sexual response cycle is the
absence in women of a refractory period after orgasm. This enables women to have several
orgasms within a short period of time. The experience of orgasm by women is very variable
and in a significant proportion of women is not regularly achieved except by
self-stimulation. Ejaculation from glands, homologous to the male prostate, occurs in a
proportion of women at the time of orgasm.
In the resolution phase of the sexual response cycle
detumescence occurs: the more prolonged the arousal the more gradual is resolution; if
sexual tension has been high but without an orgasm then resolution is slower.
Female Sex Hormones
The ovary produces oestrogens - oestradiol, oestrone and oestriole - and progesterone, in
amounts which wax and wane with the menstrual cycle. Their production is under the control
of stimulating hormones and from the anterior pituitary gland. Their action is to create
in the womb a suitable milieu for the implantation of a fertilised ovum. Under the
influence of oestrogens, and later progesterone, the endometrial lining of the womb
proliferates in preparation for implantation, and in the absence of a fertilised ovum is
subsequently shed at menstruation (the menstrual period).
Androgens (testosterone and DHEA) are secreted by the
adrenal gland and assist in maintaining libido. They are sometimes prescribed for this
purpose, in which case there are additional benefits to energy and wellbeing.
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