Puberty

Question 1

What is puberty

Answer 1

Describes the physiological, morphological, and behavioural changes as the gonads switch from infantile to adult forms

Question 2

What are the physical changes of puberty

Answer 2

-growth (have a growth spurt, rapid increase in heighr due to sex hormones)

Girls
* Breast development
– Controlled by ovarian oestrogens
* Pubic and axillary hair
– Controlled by ovarian and adrenal androgens

Boys:
* Development of penis, scrotum and pubic hair growth
* Enlargement of larynx and laryngeal muscles (voice deepening)
* increase of body muscle mass
– Controlled by testicular (and adrenal)
androgens

Growth: puberty changes increase in height velocity, peak and then decrease growth velocity (due to epiphyseal fusion)
-girls start puberty earlier and grow earlier, and peak height velocity for men is higher than women

Question 3

What is the average height gain in puberty

Answer 3

boys 28cm
Girls 25 cm

Question 4

What is the tanner stages for boys

tanner stages: to see how people develop

Answer 4

-look at pubic hair
-enlargement of penis

pubic hair
stage 1: no hair,
stage2: slighly curly hair on base of penis
stage 3: thicker curly hair on mons pubis
stage 4: adult type hair on medial surface of thighs
stage 5L spread of medial thigh

Question 5

What are the tanners stages of girls

Answer 5

look at pubic hair and breast development

Question 6

What is the first thing you see in boys and girls

Answer 6

boys: onset of pubic hair, then growth of testicles, height growth

girls: onset of pubic hair, then breast enlargment, height growth

Question 7

How do we assess puberty start in boys

Answer 7

-use orchiodometer to see assess testciualr volume
-puberty starts at 4ml should increase to 15ml

Question 8

How do we assess puberty start in girls

Answer 8

look at tanner stage 2
-outward dipping of areola, and it gets slightly darker

menarche is last stage of puberty: menarche use to 18 in 1830 -> 12

Question 9

What do we need for humans

Answer 9

-sex chromsomes
-a hypothalamus
-a pituritary
-ovary/testes
-responsive tissues

Question 10

How do male gonads develop

Answer 10

SRY gene
-enables gonads to differenate into testes
-sertoli cells: sperm production
-leydig cells: make testosterone, they also secrete AMH, to regress mullerin anatomical structures paramesonephric ducts (give rise to uterus and vagina)
-testosterone or DHT cause the devleopment he mesonephric ducts develop to form the primary male genital ducts (vas defferns, epididymis etc)
-DHT binding androgen receptor leads to penile enlargemnt

Question 11

Do you know your HPA axis

Answer 11

YES OR NO

if not its very important cba to write down

inhibin produced by sertoli cell is an indicator of work

Question 12

What is adrenarche

Answer 12

in childhood
you only have zona glomerulosa, and zona fasticulta

the zona reticualris randomally develops at a simialr time to puberty

Question 13

What are clinical features of adrenarche

Answer 13

Clinical Features:
* Transient growth acceleration
* pubic / axillary hair
* oily skin, mild acne
* adult-type body odour

adrearche not puberty

Question 14

Precocious puberty

Answer 14

onset of secondary sexual haracteristics before 8 yrs (girl), 9 yrs (boy)

Menarche before 9 yrs may lead to short stature

Question 15

Delayed puberty

Answer 15

absence of secondary sexual characteristics by 13 yrs (girl), 14 yrs (boy)

Delayed puberty leads to reduced peak bone mass and osteoporosis

Question 16

What is premature adrenarche

Answer 16

Increased adrenal androgen secretion (above age specfic age)

+have clinical eatures of androgen action (pubic/axillary hair, body dour, mild acne, oily hair and skin before 8 in girls and 9 in boys

Question 17

How do we know if early puberty is central

Answer 17

GnRH dependant
-more common in girls than boys

-idiopathic
CNS tumors

CNS disorders
Secondary central precocious
puberty (i.e. CAH)
* Psychosocial

Question 18

What is peripheral precocious puberty

Answer 18

GnRH independant

causes
-Increased androgen secretion
-Gonadotropin secreting tumours
McCune-Albright syndrome
* Ovarian cyst
* Oestrogen secreting neoplasm
* (Hypothyroidism)
* Iatrogenic or exogenous sex hormones

Question 19

How do we know if its central or peripheral

Answer 19

Use GnRH test

-inject analgoue to GnRH
-measure LH, FSH at baseline and after GnRH if given
-if puberty is central, pituariatry cells respond, you see an increase of LH over FSH

if its peripheral
-you would not see LH, FSH levels increase

Question 20

What are the consequences of early puberty

Answer 20

-growth -> short stature in growth
-increseing evidence children with PP develop metabolic conditions
-altered self image,

Question 21

Treatment of central PP

Answer 21

Long acting GNRH analogues
-blocks release of LH, FSH stops puberty
-given as injection every 10 weeks
-usually discontinued when of pubertal age

Question 22

What is meant by delayed puberty

Answer 22

Absence of secondary sexual
characteristics by
– 13 years in a girl
– 14 years in a boy
* First period after 15 years of age

Question 23

What are the cause of delayed puberty

Answer 23

is it in brain or gonads

primary failure (hypergondatrophic hypogonadism) -> ovaries/testes does not respond to FSH, LH

secondary failure -> hypogondratrophic, hypogonadism (low FSH, LH), ovaries.testes don’t have hormones to respond to

Question 24

How can you differnaite between intact or impaired HPG axis

Answer 24

intact
-can be due to chronic disease, poor nutrition, psychosocial deprivation,
steroid therapy, hypothyroidism

impaired GnRH
- Tumours adjacent to HP axis (cranio, optic glioma,
germinoma)
* Congenital anomalies (hypopituitarism, septo-optic
dysplasia)
* Irradiation & trauma
* GnRH/LH/FSH deficiency (including Kallmann, Prader-Willi,
Laurence-Moon-Bardet-Biedl syndrome).

Question 25

What would be the peripheral causes of delayed puberty

Answer 25

Male
* Bilateral testicular damage (cryptorchidism, torsion,
haemochromatosis)
* Syndromes associated with cryptorchidism (Noonan,
Prader-Willi, Laurence-Moon-Bardet-Biedl syndrome)
Female
* Disorders of Sex Development (eg. Complete Androgen
insensitivity syndrome (CAIS)
* Toxic damage (thalassaemia, galactosaemia)
Both sexes
* Gonadal dysgenesis (female; Turner syndrome (45XO),
male; Klinefelter syndrome (47XXY))
* Irradiation/chemotherapy

Question 26

Key investigations

Answer 26

LH, FSH,
Oestrodiol, teststorne

karoytpe
GnRh TEST

Question 27

Treatment of delayed puberty

Answer 27

BOYS
* Testosterone: usually Sustanon® 50 (-250) mg intramusclary slowly up titrated

GIRLS
* Oestrogen: usually 17b-ethinyl-oestradiol transdermal patches (i.e. Evorel 25), slowly up titrated starting with ¼ patch 3 days on, 3 days off