Male and female sexual function

Question 1

Discuss sex and gender

Answer 1

• Biological Sex:
  
  • Male XY, female XX, variations in genotype and phenotype.
• Gender:
  
  • Social and personal construct of identity including male, female, cis, trans, nonbinary identities, questioning and many others
  • Fluidity of Identity:
  • Identity may change over time.
  • May also be non-gendered
• Stereotypes:
  
  • Influence of societal expectations on masculinity and femininity, as a reference for sexual and other behaviours

Question 2

Discuss intersex and transgender

Answer 2

• Transgender:
  
  • Identity differing from biological sex,or gender assigned at birth
  • dysphoria to body and strong desire to change
  • 1/11-30000 in men, 1/30-150,000 in women
• Intersex:
  
  • Conditions where sex characteristics (sex chromosomes, gonads, genitalia, physiology) are not exclusively male or female.
  • Occurs at conception or foetal development

Question 3

Describe the impact of being intersex on sexual function

Answer 3

• Variable influence
• Depends on initial individual intersex situation and if subsequent medical intervention
  
  • Hormonal
  • Surgical
  • Age at which this occurs
• Independent of sexual orientation/attraction

Note that there is a general trend towards delaying surgical development until individual is old enough to have a say, unless acute problem.

Question 4

Discuss sexual orientation

Answer 4

• Attraction:
  
  • Heterosexual, homosexual, bisexual, asexual, situational etc.

Note that sexual orientation is also fluid.

• Independence from Gender:
  
  • Sexual orientation not linked to gender identity.

Question 5

Describe the functions of sexual activity

Answer 5

• Reproduction
• Recreation: pleasure/fun, intimacy/relationship enhancing, stress relief
• Commerical, other gains
• Exploitative: issues of power imbalance, and consent

Question 6

Discuss some historical perspectives and discoveries regarding sexual function

Answer 6

• Alfred Kinsey:
  
  • Contributions to understanding sexual behavior: women can have orgasms, and that people engage in sex for pleasure, not just for procreation
  • Around this time: drug yohimbine (a poor aphrodisiac), penile reconstruction surgery and penile implant surgery
• Masters & Johnson:
  
  • Exploration of the sexual response cycle and physiological changes: elucidated the sexual cycle
  • At this time:
    
    • ads for penile vacuum pumps
    • serotonin and inhibition of sexual response in rats
    • Clomipramine and delayed ejaculation

Question 7

List the phases of the sexual cycle

Answer 7

1. Desire
2. Excitement
3. Plateau
4. Orgasm
5. Resolution

Question 8

Describe desire

Answer 8

• desire: also known as lust or libido
• how often one thinks about or wants sex
• there is intra-personal variation: over time or in different situations, or with health issues
• inter-personal variation
• Desire is influenced by
  
  • oestrogen and progesterone: menstrual cycle, thought to be higher mid-cycle ^[contraception could impact libido]
  • testosterone increases libido, and affected by frequency of sexual activity
  • frequency of sexual engagement and satisfaction
  • dopamine – enhances motivation and arousal
  • adrenaline
  • mood (can decrease)
  • recreational drugs (can decrease)
• limerence: passionate love, obsessional high desire at start of a relationship

Question 9

Discuss some issues with desire

Answer 9

• limbic inhibition may cause reduced desire
• mental health: mood disorders and psychosis
• androgen deficiency (in both men and women) and menopause
• medication
• recreational drugs
• poor health and chronic disease
• reaction to long standing sexual function problem
• relationship: hostility, ‘sparks gone out’
• beliefs
• mismatch in desire or desire discrepancy (which widens if not addressed)

Note that it is difficult to distinguish between normal and myths due to individual variation.

Question 10

Describe excitement

Answer 10

• Sexual arousal
• Sensory Inputs:
  
  • The importance of touch, sight, smell, hearing, and taste.
    
    • Pornography, fetishes, paraphilias
• Negative effect of cognition: personal beliefs, societal influences, situational influences, previous experiences
• Increased tactile sensitivity
• Sense of urgency
• Vaginal transudate forms; bulbo-urethral gland secretion (pre-ejaculate)
• Vaginal ‘tenting’
• Flushing of skin
• Increased HR, RR, BP, muscular tension
• Increased blood flow to erectile tissue of female and male genitals

Question 11

Discuss the changes during erection

Answer 11

• when flaccid, the penis is under sympathetic control or adrenergic tone
• sinusoids, arterioles and arterial smooth muscle is constricted
• arteriolar inflow is minimal
• no venous obstruction
• n.b. intracavernous pressure is same as venous pressure

Tumescence: Filling of Erectile Tissue

• Parasympathetic NS Stimulation:
  
  • Loss of adrenergic tone leading to vascular smooth muscle relaxation.
• Vascular Changes:
  
  • Arteriolar dilation, trabecular relaxation, sinusoids filling and expanding.
    = erectile tissue expansion
• Compression of venules in sinusoidal space and subtunical venous plexuses obstructing outflow.
• Ischiocavernosus muscle contraction squeezing crura.

Question 12

Describe management of erectile dysfunction

Answer 12

• 1970-90s Approaches:
  
  • Vascular surgery, inflatable implants, injectable vasodilator drugs.
• NO’s Role:
  
  • Understanding the role of nitric oxide in vasodilation of erectile tissue.
  • action of sildenafil, initially developed for angina – much more effective at vasodilation in penis
• Risk Factors:
  
  • Hypertension, diabetes, high lipids, smoking. ^[CVS/PVS]
• Cavernous Nerve releases neurotransmitters
  
  • this leads to the production of NO which diffuses into and enters smooth muscle cells
  • NO stimulates the conversion of GTP to cGMP
  • cGMP induces a chemical cascade
  • results in reduced intracellular calcium and smooth muscle relaxation
  • note: PDE5 coverts cGMP to GMP, switches off this effect
  • sildenafil inhibits this enzyme to prolong relaxation/vasodilation

Question 13

Discuss erectile dysfunction

Answer 13

• **Importance to All Genders
• Note: Orgasm and ejaculation possible with partial erections.
• Causes of Dysfunction:
  
  • Age-related, reduced arterial flow (in large and small vessels, atherosclerosis, diabetes), veins leaking, nerve damage, Peyronne’s disease (fibrous plaques impinge on erectile tissue of penis)
• PDE5 Inhibitors:
  
  • Only males benefit

Question 14

Discuss the plateau and changes in males and females

Answer 14

• Short Phase:
  
  • Disputed
• Men’s Changes:
  
  • Maximum penile and testicular engorgement, increased pre-ejaculate from bulbo-urethral/Cowper’s glands
  • Erection may vary in firmness

From excitement to plateau:
- full erection of penis
- testes elevate towards perineum to increasing in size and becoming fully elevated
- skin of scrotum tenses, thickens and elevates to scrotum thickening
- colour of glans penis deepens
- Cowper’s gland secretion
- Prostate enlarges

• Women’s Changes:
  
  • Increased blood flow to labia, vaginal expansion and elevation, elevated uterus, orgasm becomes inevitable
  • From the excitement to plateau phase:
    
    • uterus elevates up and away from vagina to being fully elevated
    • vaginal lubrication appears
    • inner labia swell, to increase in size and turn bright red
    • outer third of vagina forms orgasmic platform
    • clitoris enlarges and retracts under hood

Question 15

Discuss changes in males and females at plateau

Answer 15

• From the excitement to plateau phase:
  - uterus elevates up and away from vagina to being fully elevated
  - vaginal lubrication appears
  - inner labia swell, to increase in size and turn bright red
  - outer third of vagina forms orgasmic platform
  - clitoris enlarges and retracts under hood

From excitement to plateau:
- full erection of penis
- testes elevate towards perineum to increasing in size and becoming fully elevated
- skin of scrotum tenses, thickens and elevates to scrotum thickening
- colour of glans penis deepens
- Cowper’s gland secretion
- Prostate enlarges

Question 16

Describe orgasm in females

Answer 16

• Female Genitals:
  
  • Pelvic floor: 3-8 contractions
  • contractions of the smooth muscle of the vagina and uterus
  • possible ejaculation although components not clear
    
    • urine?
    • peri-urethral
    • Bartholin’s gland secretion
  • repeated orgasm possible
  • often needs direct stimulation of the clitoris, labia, and introitus rather than vaginal penetration
• males and females vary in the intensity og orgasm
• also characterised by skeletal muscle contraction and verbalisations
• rise to peak of intensity

Question 17

Describe orgasm in males

Answer 17

Emission and Ejaculation

• Emission:
  
  • Seminal vesicles contract rhythmically to release fluid into prostatic urethra
    
    • secretions from prostate (make the bulk of semen)
    • peristaltic contraction of vas deferens
    • small volume of fluid into ejaculatory duct

Note: pre-ejaculate function not clear
- pH for sperm survival
- lubricate head of penis to increase pleasure
- lubricate urethra to ease expulsion of semen

• Ejaculation Phase:
  
  • Rhythmic contraction of bulbospongiosus muscle
  • simultaneous sphincter actions: internal sphincter closure and external sphincter open to allow expulsion of semen = sympathetic reflex
  • return of sympathetic control f sinusoids = constriction

Question 18

List factors predisposing retrograde ejaculation

Answer 18

• Associated with:
  - age
  - alpha-adrenergic blockers
  - diabetes
  - damage to sympathetic chain or presacral nerves
  - urethral strictures (STIs uncontrolled; trauma)
  - congenital abnormalities
  - prostate surgery damages the internal sphincter or nerves

Question 19

Discuss rapid ejaculation and its causes

Answer 19

• 13% of men attending clinics for sexual problems: physiological variation (neurological input leading to shorter plateau) OR anxiety/sympathetic overdrive
• primary or secondary occurrence (SSRIs and tricyclics)
• Associated with:
  
  • Anxiety
  • ED may precede it
  • low libido
• Relationship problems - expectations not met

Question 20

List ejaculation latency times

Answer 20

• Study Findings:
  
  • Range from 0.55 to 44.1 minutes, with a mean of 5.4 minutes.
• Categories:
  
  • Rapid ejaculation (<1 min), probable rapid ejaculation (1.5), not rapid ejaculation (>2).

Note that short time to orgasm also occurs in females, but is not well studied.

Question 21

Describe delayed orgasm and anorgasmia

Answer 21

• Causes:
  
  • Nervous system dysfunction e.g. MS, diabetes
  • drug-related: SSRIs, antipsychotics
  • psychological factors
  • reduced/different/inadequate stimulation

Treatment: SSRIs

Question 22

Describe resolution in males and females

Answer 22

• Male Genitals:
  
  • Erection declines, but may not in younger people
  • acute sensitivity of penis
  • testicles and scrotum return to normal size and position
• Female Genitals:
  
  • Reversal of tissue engorgement aka detumescence
  • Acute sensitivity of clitoris
  • Uterus, vagina, clitoris and labia return to normal position

Among both males and females:
- relaxed feeling +/- sleepiness: endorphins
- refractory period - unable to achieve erection, low desire
- duration increases with age

Question 23

List and describe the types of erections

Answer 23

• Psychogenic:
  
  • Tuning out non-erotic influences, focus on erotic stimuli, and perception of sexual pleasure
  • Brain arousal centres are stimulated and trigger physiological changes
  • Decreases with age
• Reflex Erections:
  
  • S2-4 reflex arc i.e. the pudendal nerve and parasympathetic outflow
    
    • manual or electrical stimulation
    • enhanced by erotic stimuli.
• Nocturnal Erections:
  
  • Occur during REM sleep
  • Can have 4-6 a night, lasting 15-25 mins
  • Can occur with sexual dreams
  • Early morning erection (occurs less with age)
  • Reduced by:
    
    • depression
    • sleep apnoea
    • age
    • androgen deficiency
    • drugs (Alcohol, marijuana, narcotics, antiandrogens, tobacco, antidepressants, benzodiazepines, beta blockers, anticonvulsants)
    • Note that it occurs in both males and females: less well studied in females

Question 24

Describe the effect of transitioning on sexual function

Answer 24

• Depends on where they are in the change process, and what has changed
• Puberty blockers
• Hormone therapies
• Genital or “bottom surgery”: aims to preserve erectile tissue and erogenous skin
• Limited research on sexual function and satisfaction
• Loss of fertility
• F to M:
  
  • testosterone enlarges clitoris, may increase desire
  • generally report good sexual functioning independent of type of surgical procedure
  • breast removal/”top surgery”: nipple sensitivity may be reduced
  • construction of a phallus from skin transplant and implant
  • construction of scrotum with implants
• M to F:
  
  • androgen blockers and oestrogen decrease desire
  • report high satisfaction post-surgery: orchidectomy, penectomy, construction of vulva and vagina
  • some remain able to orgasm

Question 25

Describe the effect of aging on sexual function

Answer 25

- Longer to achieve full erection/engorgement - Reduced filling of erectile tissue (decline of vascular function) - More difficult to sustain erection - Need more direct stimulation of genitals - Less intense orgasm - Detumescence quicker - Refractory period longer - Ejaculatory volume less, thinner - Vaginal dryness causes discomfort - Medical conditions affect function – vascular, neurological, medications - ***Experience changes but does not mean pleasure decreases***

Question 26

Describe variability in sexual function

Answer 26

- All people may have sexual needs - Needs vary - Physical capacity - Reduced sexual function eg sensory loss from spinal cord injury, chronic disease - May need assistance - May be limitations – fertility, movement - Cognitive capacity impacts on - acceptance of their sexual needs- stigma - Access - Ability to negotiate sexual encounters - Vulnerability to non-consenting sex

Question 27

List and describe the determinants of sexual function

Answer 27

- **Multifactorial Nature:** - Resulting from genetics, endocrine, vascular, nervous systems (brain and PNS, conscious and reflex) - **Psychosocial Influences:** - Beliefs, attitudes, experiences, social norms, and cultural factors play a significant role. - Prominent in media and online platforms.