Puberty

Question 1

Define puberty?

Answer 1

The physical changes that turn a child’s body into an adult one that is capable of sexual reproduction and fertilisation

Question 2

What is adrenarche?

Answer 2

Adrenal maturation with increased production of adrenal androgens

Usually no signs of this occurring except acne developing in some cases

Question 3

When does adrenarche occur?

Answer 3

In girls after age 6

In boys after age 7

Question 4

When does gonadarche occur?

Answer 4

In girls after age 8

In boys after age 9

Question 5

What is gonadarche?

Answer 5

Gonadal maturation and first signs of sex steroid activity

Question 6

What is:

• pubarche
• thelarche
• menarche?

Answer 6

Pubarche = growth of pubic hair

Thelarche = breast development

Menarche = vaginal bleeding

Question 7

How is puberty staged, and what is the staging based on for each gender?

Answer 7

Tanner’s staging

Girls: based on pubic hair and breasts

Boys: based on pubic hair, size of testes and penis

Question 8

In which gender does puberty start earlier, and in which one does it last longer?

Answer 8

Starts earlier in girls

Lasts longer in boys

Question 9

What is the full name of the hormone DHEAS? And where is it made?

Answer 9

Dehydroepiandrosterone

Primarily produced in adrenals

Question 10

Where is androstenedione produced?

Answer 10

Mixed adrenal and gonadal

Question 11

Where is testosterone produced?

Answer 11

Gonads

Question 12

What are gonadotropins? Give examples.

Answer 12

Hormones released by the pituitary gland that stimulate the activity of the gonads

FSH and LH

Question 13

Describe how the levels of gonadotropins change throughout life?

Answer 13

Levels rise before birth

At birth they drop down and remain very low through childhood until gonadarche

Here they rise, which is what makes puberty happen

Levels remain high throughout reproductive life

At menopause they rise further due to ovary not responding to gonadotropins released by pituitary, the pituitary releases more hormones

Question 14

Draw out the female HPG axis?

Answer 14

Hypothalamus releases GnRH

Stimulates pituitary to release FSH + LH

Stimulates Gonads (ovaries) to produce oestradiol

Question 15

Draw out the male HPG axis?

Answer 15

Hypothalamus releases GnRH

Stimulates pituitary to release FSH + LH

LH Stimulates Testes Leydig cells to produce testosterone

FSH stimulates sertoli cells to produce androgen binding globulin

Question 16

What defines precocious puberty?

Answer 16

Puberty occurring before age 8 for girls and age 9 for boys

Question 17

What defines delayed puberty?

Answer 17

No signs of puberty by age 13 for girls and 14 for boys

Question 18

What things impact the age of onset of puberty?

Answer 18

Genetic factors

Socio-economic factors: famine can delay onset

Environmental: nutritional status, stress, emotional deprivation, anorexia

Adiposity: higher BMI causes earlier menarche

Question 19

What does gynecoid and android mean?

Answer 19

Gynecoid: woman-like
Android: man-like

Refers to body shape and appearance

Question 20

Describe the differences in muscle and fat distribution between males and females?

Answer 20

Men have more muscle cells and larger muscle cells

Women have twice as much body fat which is what creates their gynecoid shape

Question 21

Name 2 types of precocious puberty?

Answer 21

True precocious puberty

Precocious pseudopuberty

Question 22

What is true precocious puberty?

Answer 22

Early onset of puberty caused by a disruption to inhibition to GnRH neurons

So excess GnRH is released, which causes excess gonadotropins, which causes puberty

It is a central problem

Question 23

What is precocious pseudopuberty?

Answer 23

Early onset of puberty caused by an increase in peripheral sex steroid levels, and not due to a central problem

Question 24

Causes of true precocious puberty?

Answer 24

Idiopathic

Disruption of inhibition of GnRH neurons by a:

• CNS tumours
• CNS disorder
• cranial radiotherapy

Question 25

Causes of precocious pseudopuberty?

Answer 25

Sex hormone secreting tumours resulting in higher levels in blood

Gonadotropin secreting tumours

Ovarian cyst

Iatrogenic or exogenous sex hormones

Question 26

Treatment of precocious puberty?

Answer 26

Zoladex - a GnRH analogue

Overstimulation of the pituitary causes desensitisation, and thus less release of LH and FSH

Question 27

What is the difference between premature thelarche and gynaecomastia?

Answer 27

Premature thelarche: early onset development of breasts in girls

Gynaecomastia: development of breast tissue in males

Question 28

How would you manage gynaecomastia?

Answer 28

Usually transient so leave it

Unless it continues after finishing of puberty then it might be best for psychological reasons to intervene surgically

Question 29

What types of delayed puberty are there?

Answer 29

Idiopathic

Hypogonadotrophic hypogonadism

Hypergonadotrophic hypogonadism

Question 30

What is idiopathic delayed puberty?

Answer 30

Delayed activation of the GnRH hypothalamic pulse generator

So puberty doesn’t start

It is unknown why this happens!

Question 31

What is the GnRH hypothalamic pulse generator?

Answer 31

A part of the hypothalamus that is activated to trigger release of GnRH that will trigger the start of puberty

Question 32

What is hypogonadotrophic hypogonadism?

Answer 32

Sexual infantilism which is caused by deficiency of gonadotropins (FSH, LH)

Gonads are not stimulated to trigger puberty

Question 33

What is Hypergonadotropic hypogonadism?

Answer 33

Problems with gonads so no triggering of puberty

Enough gonadotropins are being made, and since the gonads don’t respond to the gonadotropins the pituitary gland makes more (hyper)

Question 34

Give some causes of hypogonadotrophic hypogonadism?

Answer 34

CNS tumours
Radiation
Head trauma
Gonadotropin deficiency disorders

Question 35

Causes of hypergonadotrophic hypogonadism?

Answer 35

Males: Klinefelter’s syndrome (XXY)

Females: Turner’s syndrome (partial or complete loss of an X)