Lecture 27 - Puberty

Question 1

Characteristics of puberty?

Answer 1

secondary sex characteristics appear and mature, adolescent growth spur occurs, fertility is achieved, psychological effects

Question 2

Causes of puberty?

Answer 2

maturation of hypothalamic-pituitary gonadotropin unit, stimulation of sex organs, secretion of sex steroids

Question 3

First signs of puberty?

Answer 3

boys 11 1/2yr: teste enlargement, later growth spurt; girls 9 1/2 - 10 1/2: breast development, growth spurt

Question 4

Breast development?

Answer 4

thelarche

Question 5

Pubic hair development?

Answer 5

pubarche

Question 6

Gonad development?

Answer 6

gonadarche

Question 7

first menstrual period?

Answer 7

menarche

Question 8

breast development in boys?

Answer 8

gynaecomastia

Question 9

Staging female puberty?

Answer 9

contour of areola, pubic hair

Question 10

Staging male puberty?

Answer 10

testicular volume, pubic hair

Question 11

Nucleus of puberty initiation?

Answer 11

median pre-optic nucleus

Question 12

Aromatase?

Answer 12

produced by fat, converts test to oestrogen leading to female characteristics in boys

Question 13

LH and FSH release during puberty?

Answer 13

tonic pahse w beginning of night pulses -> greater tonic phase and night pulse amplitude -> day and night pulses

Question 14

Childhood to puberty transition?

Answer 14

gonadostat turned off, increased pulsatile secretion of GNRH and LH/FSH, increased sex steroids, reduced sensitivity to -ve feedback f sex steroids

Question 15

Kisspeptin?

Answer 15

regulates GnRH secretion through GPR54 receptor

Question 16

Inhibin?

Answer 16

stimulated by and negatively feeds back FSH, produced by sertoli (m) and granulosa (f) cells

Question 17

Adrenarche?

Answer 17

increased adrenal androgen production, in late childhood, not a sign of puberty but produces pubarche, trigger unknown

Question 18

Leptin?

Answer 18

increased w increased fat mass, influences timing of puberty (obese kids hit puberty earlier)

Question 19

Body composition and puberty?

Answer 19

sexes identical prior, 1.5x lean and skeletal mass in men, 2x fat mass in woemn, fat goes truncle in men, generalised in women, peak bone mass i nearly 20s

Question 20

Pubertal growth factors?

Answer 20

sex steroids, GH, IGF-I, insulin

Question 21

Precocious Puberty?

Answer 21

early with normal rate, GnRH stimulation test w measurement of FSH and LH