Puberty + adolescence Flashcards
What is the difference between puberty and adolescence?
Adolescence defined as transitional phase of growth and development between childhood and adulthood whilst puberty refers to the biological changes that occur during adolescence
Phases of adolescence: early (11-13), middle (14-17), late (18-21)
What is the mean age of onset for puberty?
Females = 11.2 years (weight can be a trigger) Males = 11.6 years
Most complete puberty within 3-5 years
What instigates the onset of puberty?
Pulsed release of GnRH from the hypothalamus stimulating release of FSH and LH from the anterior pituitary which control the levels of hormones produced in the gonads (testosterone, oestrogen, progesterone)
How does bone develop differ between males and females throughout puberty and adolescence?
Male bone mass increases more than females - due to bone size not increased bone density
What physical changes occur during female puberty?
Breasts develop and enlarge
Pubic/ axillary hair begin to grow
Growth spurt and widening pelvis
Increased fat deposit in subcutaneous tissue, particularly around hips and breasts
What are Tanner’s stages of puberty in females?
Stage 1 - pre-puberty
Stage 2 - areolar enlargement with breast bud; few hairs along labia
Stage 3 - enlargement of breast and areolar as single mound; curly pigmented hairs across pubes
Stage 4 - projection of areolar above breast as double mound; small adult configuration of pubic hair
Stage 5 - adult maturation
What physical changes occur during male puberty?
Growth of testicle to approx. 20ml volume - FIRST SIGN
LH stimulates interstitial cells of the testes to increase testosterone production
Increased height, weight, muscle and bone mass
Larynx enlarges - voice deepens and breaks
Hair growth (face, chest, axillae, abdomen, pubis)
Scrotum, penis and prostate gland increase in size
Seminiferous tubules mature and spermatozoa produced
What can be used to measure testicular size?
Orchidometer
What hormones control spermatogenesis?
FSH + LH secreted from anterior pituitary - LH stimulates secretion of testosterone from Leydig cells
What is spermarche?
Onset of sperm emissions
What are Tanner’s stages of puberty in males?
Stage 1 - pre-puberty
Stage 2 - enlargement of testes; few dark hairs at base of penis
Stage 3 - lengthening of penis; further enlargement of testes; curly pigmented hairs across pubes
Stage 4 - broadening of glands penis; growth of testis; small adult configuration, thighs spared
Stage 5 - adult maturation
What are Tanner’s stages of puberty assessing males and females?
Development of secondary sex characteristics:
Females = breast size + pubic hair Males = genital maturity + pubic hair
What is precocious puberty?
Early puberty - 8 years in girls, 9.5 years in boys (more common in girls)
What age is classed as delayed puberty?
Lack of secondary sexual characteristics (by 13 years in girls and 14 years in boys)
What factors contribute to sexual orientation?
Environmental, emotional, hormonal and biological factors - no single gene or environmental factor, complex interactions determine one’s sexual orientation