Physiology of Puberty Flashcards
Puberty:
- stage of physical maturation in
which an individual becomes
physiologically capable of pro-
creation - transition from childhood to
reproductive maturity
Onset of Puberty:
- 8-13 in girls
- 9-14 in boys
Physical changes in puberty:
- growth spurt
- secondary sex characteristics:
pubic & axillary hair, breasts, male
voice changes - menarche/spermatogenesis
What are growth spurts?
short periods of time when child experiences quick physical growth in height and weight
Growth Spurt: Signs:
- increased appetite: child’s
nutritional needs increase before
and during growth spurt - increase in bone and muscle
growth - increase in amount of fat stored in
the body
Chronological Order of Puberty: Girls:
- growth spurt
- thelarche: breast development
- pubarche: pubic hair
- adrenarche: axillary hair
- menarche: menstruation
*not always true
Chronological Order of Puberty: Boys:
- testicular enlargement
- penile length increases
- pubic hair
- growth spurt
- axillary and facial hair
- deep voice
Which scale is used to describe the onset and progression of pubertal changes?
The Tanner Stages
Tanner Stages: Difference between how girls and boys are rated?
- boys are rated for genital
development and pubic hair
growth - girls are rated for breast
development and pubic hair
growth
Tanner Stages: Girl’s Breast Development:
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Tanner Stages of Male External Genitalia:
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Tanner Stages: Pubic Hair Growth:
What is minipuberty?
- HPG axis is active in utero
- and first six months in boys
- first 2 years in girls
- **quiescent until the onset of
puberty
HPG Axis:
- at onset of puberty
- hypothalamus starts to produce
pulsatile secretion of
gonadotrophin-releasing hormone
(GnRH) - stimulates the pulsatile release of
FSH and LH from the anterior
pituitary
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Role of Hormones in HPG Axis:
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Role of Testosterone in Puberty:
- increased muscle mass
- penile growth
- deepened voice
- pubic hair growth
Role of LH in Puberty:
- stimulates testosterone production
- from interstitial cells of testes
Role of FSH in Puberty:
- stimulates testicular growth
- enhances production of an
androgen-binding protein - by Sertoli cells, which are a
component of the testicular tubule
necessary for sustaining sperm cell
maturation
Puberty: Extra-Gonadal Hormonal Changes:
- increased adrenal steroid
(androgen) from adrenal cortex - involved in secondary sexual
characteristics and growth of sex
accessory structures eg prostate - increased GH secretion from
anterior pituitary increases
elevation of insulin like growth
factor -> increased growth - increased TSH secretion from
anterior pituitary in both sexes - increases metabolic rate and
promotes tissue growth