puberty

Question 1

An 11-year-old girl is having the changes associated with puberty explained to her by her GP. He explains that typically menarche is preceded by three main changes. In what order do these changes occur?

Answer 1

Stage 1 After the 8th birthday None
Stage 2 From age 9–11 Breast “buds” start to form; pubic hair starts to form
Stage 3 After age 12 Acne first appears; armpit hair forms; height increases at its fastest rate
Stage 4 Around age 13
Menarche is preceded by three physical changes in the following order: breast budding, pubic hair growth, and axillary hair growth. This is due to oestrogen, a hormone essential for pubertal development.

Question 2

first sign in males in puberty

Answer 2

first sign is testicular growth at around 12 years of age (range = 10-15 years)
testicular volume > 4 ml indicates onset of puberty

Question 3

frist sign of puberty in women

Answer 3

breast development
Normal changes in puberty
gynaecomastia may develop in boys
asymmetrical breast growth may occur in girls
diffuse enlargement of the thyroid gland may be seen

Question 4

height spurts in men and women

Answer 4

men 14

women 12

Question 5

average age of period

Answer 5

13

Question 6

what system is used to measure puberty in girls

Answer 6

The Tanner scale is a scale of physical development in children, adolescents and adults. The scale defines physical measurements of development based on external primary and secondary sex characteristics, such as the size of the breasts, genitals, testicular volume and development of pubic hair
Tanners stages:
Stage 1 (prepubertal) - elevation of papilla only - no pubic hair
Stage 2 - breast bud forms - sparse, slightly pigmented hair on labia majora
Stage 3 - Breast begins to become elevated, extends beyond areola borders - hair becomes more coarse and curly
Stage 4 - increased size and elevation. Areola and papilla form secondary mound - adult like, but sparing medial thighs
Stage 5 - final size, areola returns but papilla remains projected - hair extends to medial thighs

Question 7

what drives growth in infancy and in childhood and puberty

Answer 7

In infancy nutrition and insulin are the major drivers of growth.

We know that insulin is a major driver as in a mother with poorly controlled diabetes they will have high blood glucose and as a result, the baby will produce high amounts of insulin, at birth this high fetal insulin will continue resulting in hypoglycaemia. They will also be macrosomic thus showing how insulin drives growth. They are not dependent on growth hormone as they have a low amount of receptors and finally growth isn’t affected by hypopituitarism and there is no effect of the thyroid.

In childhood growth is driven by growth hormone and thyroxine
puberty growth is driven by growth hormone and sex steroid
high amount of growth hormone is important in growth spurts.

Genetic factors are the most important determinant of final adult height.

Question 8

tanner stages for boy in puberty

Answer 8

testicle enlargement in Tanner stage 1

penis growth and development of pubic hair tanner 2

voice change in tanner 3

Height growth spurt occurs at age 14 and reaches a maximum of 10cm/year in Tanner.