Physiology of Puberty

Question 1

Which endocrine organ is primarily responsible for most disorders of puberty?

Answer 1

The pituitary

Question 2

What is the first hormone detected in association with onset of puberty?

Answer 2

Normally, about 1-3 years before puberty is clinically evident, LH levels become detectable during sleep. Levels continue to increase as clinical puberty approaches.

Question 3

Which hormone is responsible for the initiation of puberty?

Answer 3

Hypothalamic pulsatile gonadotropin-releasing hormone (GnRH) secretion is responsible for the onset and progression of puberty.

Question 4

Which hormone is responsible for epiphyseal fusion and cessation of growth?

Answer 4

Estrogen

Question 5

What might the presence of a high BMI indicate with regard to puberty initiation in girls?

Answer 5

High BMI typically leads to early puberty in girls.

Question 6

Under what ages should an early puberty workup be initiated for girls and boys?

Answer 6

Workup is recommended for onset of puberty in boys <9 years of age and in girls <8 years of age.

Question 7

How long does it take to progress from Tanner stage 2 to Stage 5?

Answer 7

2-5 years

Question 8

What is the first sign of puberty in girls?

Answer 8

The breast bud is the first sign and usually appears at 10-11 years of age.

Question 9

After the initial sign of puberty, how long is it before menarche begins in most girls?

Answer 9

After the appearance of the breast bud, it takes an average of 2-2.5 years for menarche to occur, but can be as long as 5 years.

Question 10

Describe the typical pubertal progression in girls.

Answer 10

Thelarche, adrenarche, peak height velocity, menarche

Question 11

Describe the typical pubertal progression in boys.

Answer 11

Testicular enlargement, pubarche, increased penile length, peak height velocity, spermarche

Question 12

When is the mean age of menarche initiation?

Answer 12

12.5 years

Question 13

When does peak height velocity occur in girls?

Answer 13

Peak height velocity occurs at Tanner breast stage 2-3, typically between 11 and 12 years of age, and always precedes menarche.

Question 14

At what Tanner breast stage does menarche typically occur?

Answer 14

Menarche occurs at Tanner breast stage 4.

Question 15

How much can girls be expected to grow following the start of menarche?

Answer 15

They typically grow an additional 3 inches following initiation of menarche.

Question 16

When is normal female puberty considered late?

Answer 16

If there are no secondary sexual characteristics after 13 years of age or if >5 years have passed between the beginning and completion of puberty.

Question 17

What are the first signs of puberty in boys?

Answer 17

Testicular growth and thinning of the scrotum are the first signs of puberty in boys.

Question 18

Which occurs first, penis lengthening or growth of pubic hair?

Answer 18

Penis lengthening is followed by growth of pubic hair.

Question 19

When does the growth spurt occur in most boys?

Answer 19

In boys, growth spurts occur 2 years later than for girls and are usually during Tanner stages 4-5, usually between 13 and 14 years of age.

Question 20

When is normal male puberty considered delayed?

Answer 20

If there are no secondary sexual characteristics after 14 years of age or if >5 years have passed between the beginning and completion of puberty.