Puberty

Question 1

Broad definition of puberty **

Answer 1

Appearing an maturing of secondary sex characteristics
Adolescent growth spurt
Fertility is achieved
Profound psychological effects seen

due to sex steroid production; maturation of HPG axis and sex organ stimulation

Question 2

What is normal puberty? Boy and girl first signs

Answer 2

Puberty all in tempo:

• Central activation of HPG axis
• progressive sequential changes
• Appropriate rate over 3-4 years

Boys: testicular enlargement (prior to growth spurt)
Girls: Breast enlargement then growth spurt

Question 3

What are the three puberties of life? What inhibits puberty during childhood?

Answer 3

Fetal: For gonadal and sex organ development
Infancy: May see some pubic hair, penis increass in length
Adolescent: Typical ‘puberty’.

Gonadostat, region of brain inhibiting GnRH release

Question 4

Order of events in puberty

Answer 4

Girl: Breast development; Pubic hair; growth spurt; menarche
Boy: Increased testicular size; pubic hair;penis enlargement; growth spurt

Question 5

Does insulin impact ovarian androgen production?

Answer 5

Yes, so in PCOS, when there is an insulin resistant state, so the increased insulin cause increased androgen. Degree of virilisation

Question 6

LH and FSH release during puberty

Answer 6

Early: tonic phase increases, night pulses begin
Mid: Tonic phase increases more, higher amplitude night pulses
Late: day and night pulses

Question 7

Childhood to puberty transition

Answer 7

Gonadostat turned off, increased pulsatile GnRH, FSH and LH, increased sex steroid production, reduced sensitivty to negative feedback from sex steroid

Question 8

What is kisspeptin?

Answer 8

Product of the KISS1 gene, ligand for GPR54, metatstatic suppressing gene
Expressinh neurons in HT that send projections to preoptic nucleus (GnRH producing area).

Evidence that stimulates puberty

Question 9

Adrenarche

Answer 9

Occurs at about 8-10, and produces a weak androgen (DHEAS) that can cause pubarche.
Not a sign of puberty
Note MC’s and GC’s don’t increase

Question 10

Leptin and puberty

Answer 10

Adipositc hormone, that increases with fat mass.
Signals to stop eating.
Obese people go into earlier puberty, link?.

In leptin deficiency morbidly obese and no puberty

Question 11

How is the age of menarche changing?

Answer 11

Slowly decreasing

Question 12

How does body composition change?

Answer 12

• lean mass and sketela mass increases, in woman fat doubles

- increased bone mineral density, peaking in early 20s