Sex Hormones Flashcards
What is the definition of puberty?
Maturation of Reproductive Organs
Production of Sex-Steroids E.g. Oestradiol / Testosterone
Develop Secondary Sexual Characteristics
Attain capability to Reproduce
What is breast development called in girls?
Thelarche
What increases in boys genitalia during puberty?
Testicular volume
seen with a prader orchidometer
What is pubic hair growth called and who does it occur with?
Pubarche
both
stages I-V
What is gonadarche?
Gonadarche - Activation of gonads by HPG axis
What is menarche?
Menarche - Menstrual Cycles
What is spermarche?
Spermatogenesis
What is adrenarche?
Adrenarche - Adrenal Androgen Production (starts ~2yrs before Gonadarche)
What is pubarche?
pubic hair
what does -arche mean?
onset of
What are secondary sexual characteristics of girl in puberty?
Oestradiol:
Breast Development
Hair Growth - Pubic, Axillary
Sweat Gland Composition - Skin oiliness / Acne
Changes to external genitalia
What are secondary sexual characteristics of boys in puberty?
Testosterone:
Deepening of Voice
Hair Growth - Pubic then Axillary, facial
Sweat Gland Composition - Skin oiliness / Acne
Changes to external genitalia
What is the sequence of pubertal events in girls?
onset 8-13 y/o
What is the sequence of pubertal events in boys?
onset 9-14 y/o
tanner= development
What is the 1st and late sign of puberty in girls?
1st sign is thelarche
late sign is menarche
What is boys testicular size prepubertal and adult size?
Prepubertal < 4mls
Adult Size > 15mls
what are DHEAS/ DHEA?
adrenal androgens
What is the relationship between gonadarche (activation of HPG axis) and FSH and LH serum levels?
How do DHEA levels change between boys and girls and their ages?
Why is adrenaline more important fro girls?
Because boys make testosterone which is an androgen so they can still make pubic hair etc.
How would you describe normal GnRH secretion?
pulsatile secretion
What are the targets for LH and FSH?
FSH (follicle stimulating hormone)= Ovaries / testes (tubules)
LH (luteinizing hormone)= Ovaries / testes (Leydig cells)
How are LH and FSH linked to oestrogen?
Positive feedback triggers the anterior pituitary to release more FSH and LH. More FSH and LH cause the ovary to produce more estrogen. the ensuing LH surge is responsible for ovulation.
What is the hormonal control of puberty, and how does it change from childhood to adulthood?
Gonadarche
Childhood= quiescence/ inactivity of HPG axis
Puberty= Increased nocturnal GnRH pulsatility
Adult= Normal GnRH secretion
What happens between foetal and infanthood?
mini puberty
testicular descent
penile length
sertoli cell maturation
behavioural effects
What counts as an abnormal onset of puberty?
Mean +/- 2.5 SDs
Precocious or Delayed