The role of chromosomes and hormones (gender) Flashcards
What is someone’s sex and what 3 physical things determine it?
SEX= Biological structures, occurs as biological maturation takes place
- Egg fertilised by sperm carrying X or Y chromosome
- Gonads (testes or ovaries)
- Hormonal differences
In terms of the role of chromosomes on gender, how is a female foetus formed?
- There is an egg with an X chromosome, and it is fertilised by a sperm carrying an X chromosome
- The 2 gonads will become ovaries
- The male elements will disintegrate
- Exterior anatomy develops into female genitalia
In terms of the role of chromosomes on gender, how is a male foetus formed?
- There is an egg with an X chromosome, and it is fertilised by a sperm carrying a Y chromosome
- Gonads develop into testes
- A hormone is pumped out that absorbs all the female parts and then produces testosterone
- The result is a male with external male genitalia
What happens to males and females during puberty?
- Male or female gonads release hormones from the pituitary gland or the hypothalamus
- This is testosterone for males, oestrogen+progesterone for females
- This stimulates the production of secondary sexual characteristics such as development of breasts and pubic hair
What is the role of TESTOSTERONE in determining gender?
- Steroid hormone
-Stimulates growth of secondary sexual characteristics
(females can produce T, just less of it)
- Causes the development of male sex organs and also acts on the hypothalamus
- It’s associated with the masculinisation of the brain
- Also associated with male typical behaviour, eg aggression and competitiveness
Role of testosterone- study by Money and Ehrhardt:
A sample of girls whose mothers took testosterone drugs during pregnancy exhibited ____-type behaviours.
They also showed a lack of ______-type behaviours
What does this suggest?
- MALE
-FEMALE
This suggests that testosterone has an effect upon gender behaviour.
Role of testosterone- study by Deady
- Measured testosterone levels
- Gave BSRI to women aged 25-30
- asked questions about maternal personality (importance of having children and having a career)
- HIGH TESTOSTERONE LEVELS NEGATIVELY CORRELATED WITH LOW LEVELS OF MATERNAL PERSONALITY
——> suggests maternal drive is affected by testosterone
What’s the role of OESTROGEN in determining gender?
- female hormone responsible for onset of menstruation and foetal development when pregnant
-Males can produce small amount
-there are behavioural effects= cause pre-menstrual tension, associated with emotionality, irritability, irrational behaviour and even criminality
-Diminishing oestrogen levels= the menopause
-Oestrogen also plays a part in ‘feminising’ the brain
- Also associated with female-type behaviours such as sensitivity and co-operation
Research support for the role of oestrogen is…
ALBRECHT + PEPE
- Found that increasing oestrogen levels in pregnant baboons led to heightened cortisol production
-This assisted the development of organs and tissues in foetuses
–> suggests oestrogen plays a key role in promoting pregnancy
What is the role of OXYTOCIN in determining gender?
- Acts as a neurotransmitter
- Produced in the brains of both males and females to control key aspects of the REPRODUCTIVE system
- Acts more in females:
–>helps facilitate child birth by stimulating contractions
–>helps in breast feeding - Affects female social behaviour such as mate selection, ‘nesting’ behaviour, monogamy and nurturing acceptance and protection of offspring.
How does Van Leengoed’s study support the role of oxytocin?
- Inhibited oxytocin production female rats shortly after birth
- Mothers showed a delay in maternal behaviour
-When the effects of the antagonist (that inhibited oxytocin) wore off, normal maternal behaviour was seen
——> supports idea that oxytocin is involved in the promotion of maternal behaviour
How does Elbourne’s study support the role of oxytocin?
- Assessed the administration of oxytocin in 3000 patients in the 3rd stage of labour
- Found evidence of reduced blood loss–> supports idea of oxytocin in achieving successful child birth
