Sex and stress Flashcards
(31 cards)
According to Walter Cannon, what is the fight or flight response?
Evolutionary preparation for a threatening event.
What happens physiologically during the fight or flight response?
- Adrenal medulla secretes adrenaline and noradrenaline
- this affects glucose metabolism, stored nutrients in muscles become available.
- increases HR and BP - Adrenal cortex secretes cortisol
- converts protein to glucose
- makes fats available for energy
- increases blood flow
- increases behavioural responses (e.g. inhibits sex hormones)
How are glucocorticoids like cortisol released and controlled?
- PVN of hypothalamus secretes CRH (cortico-tropic releasing hormone), a peptide.
- CRH stimulates the anterior pituitary gland to release ACTH.
- ACTH enters circulation and stimulates adrenal cortex to release glucocorticoids
- Negative feedback system to regulate.
What are the effects of long term stress?
Poor health - more likely to get ill.
What did Cohen (1953) find?
That survivors of concentration camps have poorer health in life later on.
- could be due to poor conditions and malnutrition?
What did Theorell et al (1992) find about subway train drivers?
Those who accidentally injure or kill people are more likely to be ill months later.
What did Selye (1976) attribute the health effects of long term stress to?
Glucocorticoids - increase BP, damage muscle tissue, increase infertility, suppress the immune system, increase steroid diabetes and inhibit growth.
What are rats put in a cage next to a chamber containing a rat worse at?
Spatial navigation tasks.
When is gender determined?
At fertilisation.
What are the first sex organs to develop?
The testes/ovaries.
What are the roles of the testes/ovaries?
- Produce sperm/ova
- Secrete hormones which determine sex organs and brain (organisation effects) and activation effects at puberty.
Until what stage in pregnancy are foetuses undifferentiated?
The 6th week.
What causes the gonads to become testes?
Sry (sex-determining region Y) gene on the Y chromosome.
Why are females the default setting?
If nothing happen, female genitalia develop - something has to happen for testes to be formed.
Until what stage in pregnancy does an embryo possess the precursors to both male and female sex organs?
Three months.
What is the precursor to male sex organs called?
Wolffian system.
What is the precursor to female sex organs called?
Mullerian system.
How is it determined which precursory system withers?
In males, the testes secrete:
- Anti-Mullerian hormones (de-feminising)
- Androgens, e.g. testosterone (masculinising)
What is androgen insensitivity syndrome (Money and Ehrhardt, 1972)?
- XY but mutation prevents formation of androgen receptors.
- Testes secrete A-M hormones and androgens but no masculinisation.
What is persistent Mullerian duct syndrome (Warne and Zajac, 1998)?
- Caused by absence of AM hormone or receptors.
- In males, masculinising effect but no defeminisation so both sets of internal sex organs develop.
What is Turner’s syndrome?
- X0 foetus.
- No Y chromosome therefore no testes, but XX needed for ovaries.
- Develop normal female internal and external genitalia but can’t have children.
What is andrenogenital syndrome?
- Low levels of cortisol result in high levels of adrenal androgens.
- Early onset of puberty in males.
- In females causes enlarged clitoris and fused labia = ambiguous sex organs.
How is external genitalia developed in males and females?
- No female hormones needed.
- In males, dependent on an androgen (hence Turner’s syndrome).
When does sexual maturation occur?
When:
- Hypothalamus secretes GnRH
- Stimulates anterior pituitary gland to release gonadotrophic hormones
- Stimulates the gonads to produce their hormones (FSH and LH).
