Physiology/Anatomy of female orgasm + arousal Flashcards
1- Define arousal.
2- What is needed for arousal to occur?
1- Sexual excitement accompanied with some physical changes > precursor to achieving orgasm
2- Can be both physically and socially stimulated > Does not require physical stimulation - the imagination can be sufficient.
What changes occur when someone is aroused?
1- Excitement
2- Increased heart rate, respiratory rate and blood pressure
3- ‘Sexual flush’ reddening of mainly the chest and neck due to vasocongestion of the skin.
4- Swelling of erectile tissues - in males this is the corpora cavernosa; in females, this is the glans clitoris and accompanying structures.
5- Secretions - In males this is pre-ejaculate from the bulbourethral gland (responsible for cleaning out the urethra); In females, this is lubricating fluid.
6- Sweating
7- Salivation
8- Nipple erections
9- Cutaneous vasodilation
How are erections maintained?
- Arterial blood flow to the penis is greater than venous outflow away from it keeping the erectile tissues full of blood and consequently, swollen.
- Erectile tissue also compresses veins as it swells which can further reduce venous outflow.
What is an orgasm?
- The expulsive discharge of neuromuscular tensions at the peak of sexual response.
What anatomical structures are implicated to cause an orgasm in females?
- Glans clitoris
- Clitoral bulbs and crura
- vulva
- Vaginal walls - both proximally and distally
- Non-genital regions such as the nipples
How does an orgasm occur?
- Stimulation of the implicated areas causes sensory information to be sent to the thalamic septum of the brain. Once the stimulation reaches a threshold, the thalamic septum coordinates the release of neurotransmitters and initiates the orgasm.
Orgasms occur following two basic responses to continual stimulation.
1- Vasocongestion = the engorgement of bodily tissues with blood causing them to swell. This increases the surface area exposed to friction.
2- Myotonia = process whereby muscles tense and this can be voluntary or involuntary.
What role do these hormones play in orgasm?
- Prolactin
- Oxytocin
- Dehydroepiandrosterone
- Testosterone
- Oestrogen
- Growth hormone
- Luteinising hormone
- Adrenaline
- Prolactin > released during orgasm by anterior pituitary gland > Involved in central control of sexual behaviour by exhibiting and regulating dopamine and serotonin > Regulates further sexual response after initial orgasm
- Oxytocin > Released by posterior pituitary > Involved in contractility of uterus > Rapid release of oxytocin in women during orgasm
- Dehydroepiandrosterone > precursor to oestrogen
- Testosterone > Increases in both women and men > Orgasm frequency not related to androgen levels
- Oestrogen > Improves integrity of vaginal mucosal tissue > vaginal congestion > vasocongestion
- Growth Hormone > Regulates hypothalamus-pituitary gonadal axis > Mechanism unknown > Regulates sexual response more so in men
- Luteinising hormone > Increases after orgasm
- Adrenaline > (no comment)
What are the 4 different theories behind why females orgasm?
1- Reproduction theory
- Necessary to aid fertilisation > Sperm transport
2- Embryological by-product theory
- The female orgasm is a by-product of the embryological similarity of males and females
3- Bonding theory
- Release of dopamine and oxytocin > More likely to stay together due to orgasm > Evolutionary beneficial for the survival of the species
4- Mate selection theory
- Selection of the best partner > Attitude towards sexual encounters = attitude towards life
What are the 2 basic stages of sexual activity?
1- Arousal
2- Orgasm
1- How is arousal stimulated?
2- What innervation mediates arousal?
3- What happens to the erectile bodies during arousal?
4- What happens to glands clitoris during arousal?
5- What happens to the vulva of females during arousal?
1- Physical stimulation
> Mental state/mood important
2- Parasympathetic
3- Erectile bodies fill with blood
> Increase supply
> Decreased venous drainage
4- Moves into a more prominent position.
5- Greater vestibular gland secrete mucus to protect/ delicate skin
> Watery blood plasma derivative produced by vagina
= Frictionless/painless vaginal penetration
What does stimulation go the glans clitoris result in?
-
More reliable orgasm
> With less effort than stimulation of the vagina
When is vaginal stimulation more likely to induce an orgasm?
> What is the G-spot
- Deeper locations
> Areas of increased sensitivity of the anterior wall, due to deeper structures of the clitoris.
Describe what happens during resolution after an orgasm.
How is it different in females than males?
-
Refractory period
> Loss of erection = Return to normal
> unlikely to have another orgasm - Short + poorly defined in females = multiple orgasms in single session of sexual activity
Give some anatomical reasons why arousal may take longer or be less prominent?
1- Menstural cycle
> Ovulation = arousal response to lubrications is greater.. decreases during mensturation
2- Hormonal contraception
> Can result in increased vaginal dryness
3- Mental health medications
> Changes in arousal response… and psychological responses to libido
4- Menopause
> Decreased lubrication + Thinning of vaginal wall
5- Pregnancy/Breastfeeding
> Can cause +/- changes to sexual drive
