Sexual function and disorders

Question 1

Neural mechanisms

Answer 1

The medial preoptic area of the hypothalamus seems critical for male sex behaviour in rodents.
If you lesion the area the behaviours are abolished

In females- the ventromedial nucleus is critical for the display of female sex behaviours.

A chemical in the tears of juvenile mice deters female mice from copulation

Question 2

The Fraternal Birth Order Effect

Answer 2

Evidence that fraternal birth order is associated with male homosexuality
- The more older brothers a biological male has, the more likely they are to identify as homosexual
- 15-29% of homosexual men may owe their sexual orientation to this effect
- Robust across cultures
- Older sister or younger brothers/sisters has no effect
- Effect remains if older brothers raised in different households but does not occur in the case of older step- brothers or adopted brothers
- Implies the effect relates to maternal factors

Question 3

Sexual dysfunction

Answer 3

Masters and Johnson developed the human sexual response cycle- desire- arousal- plateau- orgasm- resolution

Types of sexual dysfunction are categorised according to phases of the human sexual response cycle

Desire- male hypoactive sexual desire disorder
Plateau- Female sexual interest/desire disorder
Orgasm- Female orgasmic disorder
Delayed ejaculation
early ejaculation
Resolution- Sexual pain disorders

For diagnosis there must be an impact on subjective distress and functioning (relationships)
symptoms must be persistent

Question 4

Paraphilic disorders

Answer 4

Satisfaction must entail either distress/harm to the individual, or to another person.

Not typically directed at another person:
Fetishistic disorder
Transvestic disorder

Directed at a non-consenting person
Exhibitionist disorder
Paedophillic disorder

Involves experiencing or inflicting suffering:
Sexual masochism disorder
Sexual sadism disorder

Question 5

Gender dysphoria

Answer 5

A disparity between an individual’s assigned gender and their perceived gender that caused distress or impairment

for diagnosis person must not be intersex

Often co-morbid with anxiety and depression