Repro 3.1 Puberty and Menopause

Question 1

When are primary sexual characteristics established?

Answer 1

Before birth

Question 2

When do male and female reproductive systems become active?

Answer 2

Puberty

Question 3

When do male hormone levels change?

Answer 3

First few months of life

Question 4

At what age do girls and boys reach puberty?

Answer 4

Girls - 8-13

Boys - 9-14

Question 5

From where are sex steroids secreted?

Answer 5

Adrenal glands and gonads

Question 6

Why do boys grow taller?

Answer 6

Growth spurt starts later so they have grown more before it starts and grow at a faster rate during the growth spurt and it is also slightly longer (10cm/year as opposed to 9cm/year in girls)

Question 7

What terminates the growth spurt?

Answer 7

Epiphyseal fusion - adult height virtually set

Question 8

What controls the development of secondary sexual characteristics in girls?

Answer 8

Gonadal oestrogens influence breast development and female genital development
Androgens from adrenals control the development of pubic and axillary hair

Question 9

What controls the development of secondary sexual characteristics in boys?

Answer 9

Testicular androgens control the development of genitalia and body hair and deepening of the voice

Question 10

What is the name for the onset of a girls first menstrual bleed?

Answer 10

Menarche

NB. This does not indicate the onset of full fertility

Question 11

What is the equivalent event for boys to menarche in girls?

Answer 11

Nocturnal erection and first ejaculation (more difficult o monitor)

NB. This does not indicate the onset of full fertility

Question 12

Describe the hormonal changes in a girl until menarche.

Answer 12

Plasma levels of FSH and LH rise gradually from about 7 years of age to reach adult levels at of soon after menarche.
Plasma oestrogen levels rise steadily until at the beginning of menstrual cycles regular cyclical rises and falls are associated with the ovarian cycle
Weak androgens are secreted from adrenal glands

Question 13

Describe the hormonal changes in boys from birth to adult level.

Answer 13

FSH and LH rise later than girls to reach adult levels around 16 years of age. This is associated with a steady rise in testosterone levels
Weak androgens are secreted from adrenal glands

Question 14

What changes in the body signal the onset of puberty?

Answer 14

The brain initiates pulsatile GnRH secretion. This does not seem to depend on any signal from the gonads

Question 15

What are the 2 theories explaining the onset of puberty?

Answer 15

Decreasing hypothalamic sensitivity to feedback -> Increased GnRH secretion
Hypothalamic mechanisms mature and steadily secrete more GnRH under other influences

Question 16

Why has the onset of puberty become steadily earlier in the last 150 years in western society?

Answer 16

The main determining factor for onset of puberty is weight. Increased average body mass has decreased the age at which the onset of puberty occurs

Question 17

Approximately what is the body weight at menarche?

Answer 17

47kg

Question 18

What is the approximate weight of the growth spurt in girls?

Answer 18

30kg

Question 19

What is the critical weight for boys for the onset of the growth spurt?

Answer 19

55kg

Question 20

How is the hypothalamus aware of the appropriate weight for onset of puberty is achieved?

Answer 20

Leptin, a fat derived hormone may indicate to the hypothalamus the attainment of the body weight

Question 21

What are some causes of precocious puberty?

Answer 21

Central:

• Meningitis/trauma (inflammation)
• tumours of the brain or spinal cord

Peripheral:

• Tumours of the gonads
• Exposure to external sources of oestrogen and progesterone

Question 22

In order, what are the stages of puberty in girls?

Answer 22

1) Breast bud appears (thelarche)
2) Pubic hair growth begins (adenarche)
3) Growth spurt
4) Onset of menstruation (menarche)
5) Adult pubic hair
6) Adult breasts

Question 23

In oder, what are the stages of puberty in a boy?

Answer 23

1) Genital development begins
2) Pubic hair growth (adenarche)
3) Spermatogenesis begins
4) Growth spurt
5) Genitalia of adult
6) Pubic hair of adult

Question 24

Define precocious puberty.

Answer 24

Physical signs of sexual maturation before 8 years or menarche before 10 years old.

Question 25

What is true precocious puberty?

Answer 25

Precocious puberty caused by premature secretion of gonadotrophins. Usually idiopathic but can be caused by CNS lesions.

Question 26

What is the effect of precocious puberty on height?

Answer 26

Shorter - growth spurt begins and terminates earlier. Oestrogen closes epiphyseal growth plates

Question 27

How would you assess a boys stage in puberty?

Answer 27

``` Height Weight Genital size Body hair Bone age Medical history ```

Question 28

Define delayed puberty

Answer 28

Lack of sexual maturation by age 15 - majority constitutional delay (benign)

Question 29

What proportion of 14 year old boys would be expected to not yet be exhibiting signs of puberty?

Answer 29

3-5% - visibly begins aged 9-14

Question 30

What is bone age and what might it indicate in delayed puberty?

Answer 30

Age suggested by bone - density, presence of epiphyseal growth plates etc. Young bone age may indicate delayed puberty Normal bone age may indicate there is a problem causing the delayed puberty

Question 31

When does the growth spurt occur in boys?

Answer 31

12 months after genital development

Question 32

How is the cause of delayed puberty in boys diagnosed?

Answer 32

Blood tests: Low testosterone indicates hypogonadism Low FSH indicates hypothalamic/pituitary problem

Question 33

How might you treat precocious puberty?

Answer 33

Treat underlying cause: Drugs to inhibit pituitary gonadotrophin secretion eg medroxyprogesterone or LHRH analogues Drugs to block androgen action e.g. cryproterone

Question 34

What disorders of the adrenal gland might cause precocious puberty?

Answer 34

Congenital adrenal hyperplasia -> hyperfunction | Cushings syndrome from adrenocortical tumour

Question 35

What is the menopause?

Answer 35

End of reproductive life

Question 36

On average, at what age does menopause usually occur?

Answer 36

50

Question 37

What causes menopause?

Answer 37

Depletion of follicles in the ovaries so gonadotropins are no longer able to stimulate follicular development - interaction between the hypothalamus, pituitary and gonads that usually maintains the reproductive cycle is broken

Question 38

What physiological changes occur with the onset of the menopause?

Answer 38

``` vasomotor changes - hot flushes (approx 80%) Regression of endo and myometrium Thinning of cervix Vaginal rugae lost Involution of some breast tissue Skin changes Bladder changes Decreased bone mass 2.5% pre year -> osteoporosis Mood changes ```

Question 39

What changes occur in the menstrual cycle in pre-menopausal women?

Answer 39

More erratic menstrual cycle Shortened follicular shortened - ovulation early or absent Less oestrogen secreted LH and FSH levels rise, FSH more (inhibin) Reduced fertility but not absent

Question 40

What changes in the menstrual cycle and relevant hormones occur in menopausal women?

Answer 40

``` Cessation of menstrual cycles No more follicles to develop as the stock is used up Oestrogen levels fall dramatically FSH and LH levels rise (FSH more) GnRH risesWh ```

Question 41

What is HRT?

Answer 41

Hormone replacement therapy Relieves symptoms of the menopause Can improve well-being Oestrogen given orally or topically by patch of gel Can limit osteoporosis but no longer recommended for first line treatment No effect on cardio changes

Question 42

When does the end of the male reproductive life occur?

Answer 42

Spermatogenesis continues throughout life but incidence of loss of libido, impotence and inability to reach orgasm increase with age Testosterone levels may decrease but without rise in LH (or FSH) suggesting a change in feedback control mechanism

Question 43

What are possible disadvantages of HRT?

Answer 43

Clots - thromboembolism | Endometrial or breast cancer

Question 44

Why are oestrogen only preparations not given to women who have had a hysterectomy?

Answer 44

Still have uterus which oestrogen therapy will increase its proliferation as it is oestrogen sensitive, increasing risk of endometrial cancer