Puberty

Question 1

what is adrenarche?

Answer 1

increase in DHEA and DHEAS

cellular remodelling of the adrenals to form the zona reticularis - allows adrenal androgen secretion

Question 2

what is pubarche?

Answer 2

growth of pubic and axillary growth due to the presence of adrenal androgens in adrenarche
assosiated with increased sebum and abnormal keritinisation

Question 3

what is gonadarche?

Answer 3

usually follows gonadarche

activation of steroids allowing the production of cable gametes

Question 4

what is the difference between gonadarche in males and females?

Answer 4

males have instantly active gametes

females take approximately 1 yr of aovulatory cycles to be activated

Question 5

what is thelarche?

Answer 5

development of breast tissue

Question 6

how does the activity of the HPG change?

Answer 6

active from 16w GA to 1-2 yrs
then reactivated at puberty
prepubertal nocturnal GnRH
highest levels in mid to late puberty
becomes pulsatile in adulthood - with no nocturnal patterns

Question 7

what is the role of kisspeptin in GnRH regulation?

Answer 7

GPR54 receptors on the GnRH neurones in the hypothalamus

Question 8

what occurs if there is a lack of GPR54 receptors?

Answer 8

the HPG is not active - so there is hypogonadotrophic hypogonadism

Question 9

what happens if there is an activation mutation of the HPG?

Answer 9

precocious puberty

Question 10

what are the development of pilosebacous units?

Answer 10

villous PSU are fine hair
differentiate into terminal PSUs - beard
OR apo-PSUs - pubic and axillary hair

Question 11

what is consonance?

Answer 11

ordered and smooth progression through the pubertal stages

varies in time pace and age, but the order remains the same

Question 12

what happens if there is a lack of consonance?

Answer 12

there is a pubertal disorder

Question 13

what is the physiology of the adolescent growth spurt?

Answer 13

occurs due to high GH in balance with oestrogen
low in oestrogen - linear growth and bone maturation
high oestrogen causes fusing of the epiphyseal plates

if there is precousios puberty there is early fusion

occurs 2 yrs early in girls

Question 14

what is the maximum growth velocity for girls vs boys>

Answer 14

9cm/yr in girls - peaks at 12

10.3/yr in boys - peaks at 14

Question 15

what is menarche?

Answer 15

development of periods- doesn’t mean they are fertilise

average 12.5 yrs – decreased over yrs due to increased nourishment

Question 16

what psychological changes occur in puberty?

Answer 16

neuronal remodelling means increased need fro independance, increased sexual awareness, development of sexual personality

later the onset, the better the adjustment

Question 17

what effect does oestrogen secretion have?

Answer 17

breast development and growht

uterus enlargement, cytology changes and secretions

Question 18

what effect does testosterone have on sexual maturation?

Answer 18

penile and scrotal development

Question 19

what effect does FSH secretion have on sexual maturation?

Answer 19

testicular enlargement and follicle developmetn

Question 20

what effect does adrenal androgens have on sexual development?

Answer 20

pubic and axillary hair growth

Question 21

what effect dies sex steroid and GH secretion have on sexual maturatoin

Answer 21

cause the growth spurt

Question 22

what happens with oestrogen removal in sexual development?

Answer 22

aovulutory menarche

Question 23

what happens when there is introduction of the LH surge?

Answer 23

ovulatory menarche begins

Question 24

what effect do androgens have on sexual develometn?

Answer 24

enlargement of the larynx - adams apple formation - voice deepens

Question 25

what is precious sexual development?

Answer 25

development of any secondary sexual characteristics before 8 in girls, 10 in boys

Question 26

what is gonadotrophin dependant precocious puberty?

Answer 26

development is in consenance
due to excess GnRH
due to excess gonadotrophin - due to a pituitary tumore\

Question 27

what is gonadotrophin independent precocious puberty?

Answer 27

loss of consenance

due to testoxicosis - activating mutation of the LH receptor- causes increased testicular volume

Question 28

what is McCune Albright sydrome?

Answer 28

gonadotrophin indépendant loss of contenance due to activation of adenyl cyclase and PKA
causes mass hyperactivity of signalling pathways and over production of hormones

Question 29

what is psuedoprecocious puberty?

Answer 29

premature adrenarche or pubarche due to CAH or bushings

premature thelarche - may be unilateral - if before 2yrs then pseudo - if after 2yrs - then precedes precoisus puberty

Question 30

what is pubertal delay?

Answer 30

absence of secondary sexual maturation by 13 yr in girls, 14yr in boya
absence if monarch e by 18 yrs

Question 31

what is constitutional delay?

Answer 31

affects both growth and puberty
secondary to chronic illness - e.g. diabeties, CF
more common in boys

Question 32

what causes hypogonadotrophic hypogonadism?

Answer 32

low FSH and low LH

Question 33

what is Kallmans syndrome?

Answer 33

X-linked KAL gene causes GnRH migration - stops GnRH production
leads to hypogonadotrophic hypogonadism

Question 34

what is hypergonadotrophic hypogonadism?

Answer 34

high FSH and high LH with low sex steroid hormones

causes gonadal dysgenisis

Question 35

what congenital diseases can cause hypergonadotrophic hypogonadism?

Answer 35

Klienfelters Syndrome (XXY)
Turners syndrome (X0)

Question 36

what can cause hypergonadotrophic hypogonadism with normal karyotype?

Answer 36

viruses - mumps

cause gonadal dysgenisis