Female Puberty Flashcards
What
In childhood, girls have relatively little GnRH, LH, FSH, oestrogen and progesterone in their system. During puberty, these hormones start to increase sequentially, causing the development of female secondary sexual characteristics, the onset of the menstrual cycle and the ability to conceive children.
Puberty starts age 8 – 14 in girls and 9 – 15 in boys. It takes about 4 years from start to finish. Girls have their pubertal growth spurt earlier in puberty than boys. Overweight children tend to enter puberty at an earlier age. Aromatase is an enzyme found in adipose (fat) tissue, that is important in the creation of oestrogen. Therefore, the more adipose tissue present, the higher the quantity of the enzyme responsible for oestrogen creation. There may be delayed puberty in girls with low birth weight, chronic disease or eating disorders, or athletes.
In girls, puberty starts with the development of breast buds, followed by pubic hair and finally the onset of menstrual periods. The first episode of menstruation is called menarche. Menstrual periods usually begin about two years from the start of puberty.
What
In childhood, girls have relatively little GnRH, LH, FSH, oestrogen and progesterone in their system. During puberty, these hormones start to increase sequentially, causing the development of female secondary sexual characteristics, the onset of the menstrual cycle and the ability to conceive children.
Puberty starts age 8 – 14 in girls and 9 – 15 in boys. It takes about 4 years from start to finish. Girls have their pubertal growth spurt earlier in puberty than boys. Overweight children tend to enter puberty at an earlier age. Aromatase is an enzyme found in adipose (fat) tissue, that is important in the creation of oestrogen. Therefore, the more adipose tissue present, the higher the quantity of the enzyme responsible for oestrogen creation. There may be delayed puberty in girls with low birth weight, chronic disease or eating disorders, or athletes.
In girls, puberty starts with the development of breast buds, followed by pubic hair and finally the onset of menstrual periods. The first episode of menstruation is called menarche. Menstrual periods usually begin about two years from the start of puberty.
Tanner Stages
The stage of pubertal development can be determined using the Tanner scale, based on examination findings of secondary sexual characteristics.
Tanner Stage
Approximate Age
Pubic Hair
Breast Development
Stage I
Under 10
No pubic hair
No Breast Development
Stage II
10 – 11
Light and thin
Breast buds form behind the areola
Stage III
11 – 13
Course and curly
Breast begins to elevate beyond the areola
Stage IV
13 – 14
Adult like but not reaching the thigh
Areolar mound forms and projects from surrounding breast
Stage V
Above 14
Hair extending to the medial thigh
Areolar mounds reduce, and adult breasts form
Hormonal Changes
Growth hormone (GH) increases initially, causing a spurt in growth during the initial phases of puberty.
The hypothalamus starts to secrete GnRH, initially during sleep, then throughout the day in the later stages of puberty. GnRH stimulates the release of FSH and LH from the pituitary gland. FSH and LH stimulate the ovaries to produce oestrogen and progesterone. FSH levels plateau about a year before menarche. LH levels continue to rise, and spike just before they induce menarche.
