Sex Differences: Lectures 1-2

L3: Sex Differences in the Body
Biological Differences
Genetic/ chromosomal sex
Sexual differentiation
Development of sex organs
Internal vs. external sex organs
Factors determining the development of male sex organs
Testis-determining factor
Anti-Mullerian hormone
Androgens
Factors determining the development of female sex organs
Differences in sex development DSD
Sexual maturation
Puberty
Sex hormones overview
Masculinising effects of estrogen




Biological Differences
Types of sex difference:

Genetic or chromosomal sex

Gonadal sex

Internal reproductive system

External reproductive system

Pubertal sex changes

Hormonal sex

Brain sex

Behavioural and ‘cognitiveʼ sex

Sexual identity


Genetic/ chromosomal sex
23 chromosomes



L3 Sex Differences in the Body 1

, X and Y pair

Genetic sex of a human fetus is determined by fatherʼs sperm




Sexual differentiation




Before birth

Fetal gonads produce organisation effects of sex hormones



L3 Sex Differences in the Body 2

, Results in permanent alterations in the body/ CNS induced by a hormone at
the critical period in development

After birth

Gonads produce activational effects of sex hormones

Results in hormone effects that occur in the fully developed organism

Depends on previous organisational effects


Development of sex organs
Internal vs. external sex organs
Gonads (ovaries/ testes) and internal External sex organs:
sex organs:




Factors determining the development of male sex
organs




L3 Sex Differences in the Body 3