Session 3 - Puberty and the Menopause

Question 1

When are primary sexual characteristics established?

Answer 1

Before birth

Question 2

In which gender does puberty begin first?

Answer 2

In females

Question 3

When does male puberty begin?

Answer 3

9-14 years of age

Question 4

Give six key changes in males at puberty

Answer 4

o	Genital development begins
o	Pubic hair growth (Adrenarche)
o	Spermatogenesis begins
o	Growth spurt (10cm/year)
o	Genitalia adult
o	Pubic hair adult

Question 5

How many stages are there in male puberty?

Answer 5

5

Question 6

In general, what two things measure male puberty?

Answer 6

Genital development

Pubic hair

Question 7

What are the three main “arche” of female development

Answer 7

Thelarche
Adrenarche
Menarche

Question 8

What is the thelarche?

Answer 8

The breast bud

Question 9

WEhat is the adrenarche? When does it begin?

Answer 9

Pubic hair growth

9.5 - 14.5

Question 10

What is menarche? When does it begin?

Answer 10

Onset of menstrual cycle

12.25 -12.5 years

Question 11

What are the four main features of female puberty

Answer 11

o Breast bud (Thelarche) – the first sign that puberty has begun.
o Pubic hair growth (Adrenarche) (9.5 – 14.5)
o Growth spurt (9cm/year) (12)
o Onset of menstrual cycles (12.25 – 12.5) (Menarche)

Question 12

What hormonal factors is the start of puberty associated with?

Answer 12

Pulsatile GnRH secretion leads to steady rise in FSH and LH.

Question 13

Why does GnRH rise at the start of puberty? (2 possible reasons)

Answer 13

Rise in GnRH due to reduced sensitivity to -‘ve feedback by steroids
OR
Maturation of central secretory mechanisms

Question 14

Why are boys larger than girls?

Answer 14

Growth spurt longer and slightly faster in males than in females

Question 15

How does the growth spurt end?

Answer 15

Both sexes by epiphyseal fusion

Question 16

What is the most critical factor in timing the onset of puberty?

Answer 16

Body weight

Question 17

What is the critical weight for start of menarche?

Answer 17

47kg
If body weight falls significantly below this the reproductive cycle ceases
Signalled to brain by leptin from adipose tissue

Question 18

What is growth spurt start weight in a) males and b) females

Answer 18

a) Males - 55kg

b) Females - 30kg

Question 19

What is the adrenarche dependent on in a) males and b) females

Answer 19

a) Males - Testosterone

b) Females - Androgens in females

Question 20

Why do girls have a shorter growth spurt than males?

Answer 20

Oestrogen closes epiphyses earlier in girls. Oestrogen is needed to initiate the growth spurt, but once levels reach a certain point it causes the epiphyses to fuse.

Question 21

Why has the age of menarche decreased over the past 200 years?

Answer 21

Better nutritiion - menarche triggered by weight gain (47kg)

Question 22

What does the pineal gland detect?

Answer 22

Light

Question 23

What does the pineal gland secrete?

Answer 23

Melatonin, which is theorised to induce puberty.

Question 24

What is the significance of pineal tumours?

Answer 24

Can influence puberty in humans

Question 25

What is precocious puberty?

Answer 25

Early activation of puberty Before 8 in girls Before 9 in boyrs

Question 26

What two neurological causes of precocious puberty?

Answer 26

Pineal tumours | Meningitis

Question 27

Give an endocrine causes of precocious puberty

Answer 27

Uncontrolled gonadotrophin or steroid secretion | from hormone secreting tumours

Question 28

Give a lifestyle cause of precocious puberty

Answer 28

Obesity | Increased leptin secretion from adipose tissue

Question 29

Why are men larger than women?

Answer 29

Growth spurt is longer and faster

Question 30

What is growth spurt dependent on

Answer 30

Growth hormone and steroids in both sexes

Question 31

What is the thelarche dependent on?

Answer 31

Dependent on oestrogen | Gynaecomastia can occur as a result of conversion of testosterone to oestrogen in adipose tissue

Question 32

What is the development of male genitalia dependent on?

Answer 32

Testosterone

Question 33

What is the pre-menopause? | Three changes involved

Answer 33

Occurs at ?40 years Involves changes in menstrual cycle including - Shortened follicular phase with early or absent ovulation - Less oestrogen secretion - Less -'ve feedback, so LH and FSH levels rise - FSH rises more due to loss of inhibin Reduced fertility

Question 34

What is the menopause?

Answer 34

Cessastion of menstrual cycles at around 49-50. Occurs when female runs out of follicles.

Question 35

What are the main hormonal changes that take place in the menopause?

Answer 35

Less -'ve feedback from oestrogen so LH and FSH levels rise | FSH rises dramatically

Question 36

What are the three mains sites of menopausal effects?

Answer 36

Vascular Oestrogen sensitive tissues Bone

Question 37

What occurs in vascular tissue in the menopause

Answer 37

Hot flushes | Transient rise in skin temperature

Question 38

How can hot flushes be relieved in the menopause?

Answer 38

Oestrogen administration

Question 39

Name 6 changes in oestrogen sensitive tissues due to menopause

Answer 39

``` o Uterus o Thinning of cervix o Vaginal rugae lost o Involution of some breast tissue o Changes in skin o Reduction in bladder tone ```

Question 40

Give three effects of menopause specific to the uterus

Answer 40

Regression of endometrium Shrinkage of myometrium Shrinks away into a very small organ

Question 41

What happens to bone post-menopause?

Answer 41

o Bone mass reduces by 2.5% per year for several years o Increased reabsorption relative to production o Osteoporosis  Much greater in some than others  Major reason for fractures in later life  Can be limited by Oestrogen therapy

Question 42

What is hormone replacement therapy?

Answer 42

Hormones administered to relieve symptoms of menopause

Question 43

How is HRT adminstered?

Answer 43

Orally or topically be patch or gel

Question 44

What are the two main benefits of HRT?

Answer 44

Can limit osteoporosis | Relieves menopause syptoms