Pubertal Development: the Human Metamorphosis

Presenter First Name: 
Paola
Presenter Last Name: 
Palma Sisto
Year of Presentation: 
2011

 

Objectives

  • Describe the process by which children undergo sexual maturation
  • Highlight the method of Tanner staging used by health care professionals
  • Describe gender-specific changes that occur during puberty
  • List the common pubertal disorders health care providers will encounter


Puberty

  • Hypothalamic stimulation (GnRH) of pituitary gonadotropins (LH/FSH) leading to gonadal sex steroid production (estrogen/testosterone)
  • Sexual maturation (secondary sexual characteristics)
  • Acceleration (and eventual completion) of somatic growth
  • Capacity for reproduction(menstruation/spermatogenesis)


Onset
Females:
Initial changes 11 yrs mean (8-14 yrs range)
Breast - pubic hair - menses - axillary hair

Males:
Initial changes 11.5 yrs mean (9-13 yrs range)
Testicular volume - pubic hair - axillary hair - voice change - facial hair

Duration
Average duration 3-4 years from onset to completion of pubertal changes

Tanner Staging
James Mourilyan Tanner (1920 -2010)
British pediatric endocrinologist
Charted & photographed growth of children over period of years
Scale measures sexual maturation in adolescents based on measureable indicators:

  • size of the genitals
  • quantity of pubic hair


Pubic Hair Development

  • Tanner I  no pubic hair at all (prepubertal) [typically age 10 and younger]
  • Tanner II  small amount of long, downy hair with slight pigmentation at the base of the penis and scrotum (males) or on the labia majora (females) [10–11.5yr]
  • Tanner III  hair becomes more coarse and curly, and begins to extend laterally [11.5–13yr]
  • Tanner IV  adult-like hair quality, extending across pubis but sparing medial thighs [13–15yr]
  • Tanner V  hair extends to medial surface of the thighs [15+yr]

Female Development

  • Tanner I  no glandular tissue: areola follows the skin contours of the chest (prepubertal) [typically age 10 and younger]
  • Tanner II  breast bud forms, with small area of surrounding glandular tissue; areola begins to widen [10-11.5yr]
  • Tanner III  breast begins to become more elevated, and extends beyond the borders of the areola, which continues to widen but remains in contour with surrounding breast [11.5-13yr]
  • Tanner IV  increased breast size and elevation; areola and papilla form a secondary mound projecting from the contour of the surrounding breast [13-15yr]
  • Tanner V  breast reaches final adult size; areola returns to contour of the surrounding breast, with a projecting central papilla [15+ yr).

Male Development

  • Tanner I  prepubertal (testicular volume less than 1.5 ml; small penis of 3 cm or less) [typically age 9 and younger]
  • Tanner II  testicular volume between 1.6 and 6 ml; skin on scrotum thins, reddens and enlarges; penis length unchanged [9-11 yr]
  • Tanner III  testicular volume between 6 and 12 ml; scrotum enlarges further; penis begins to lengthen to about 6 cm [11-12.5 yr]
  • Tanner IV  testicular volume between 12 and 20 ml; scrotum enlarges further and darkens; penis increases in length to 10 cm and circumference [12.5-14 yr]
  • Tanner V  testicular volume greater than 20 ml; adult scrotum and penis of 15 cm in length [14+ yr]

Pubertal Disorders

Female

  • Precocious/delayed puberty
  • Virilizing conditions (tumors, PCOS, CAH)

Male

  • Precocious/delayed puberty
  • Feminizing conditions (tumors, gynecomastia)

Conclusions

  • Dynamic process
  • Usually 3-4 yr window
  • Identifying normal development will aid in intervening with abnormal development
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