Puberty

Question 1

What age does puberty start in girls?

What age does puberty start in boys?

Answer 1

10-12 Girls start earlier than boys

12-16 in boys

Question 2

What occurs in childhood in girls

Answer 2

• Low levels of GnRH, pituitary gland gonadotrophins and estrogen
• no follicle matureation beyond antral stage
• no menstruation
• small, non functional accessory sex organs

Question 3

What internal changes occur during puberty

Answer 3

• Increased firing in hypothalamus, GnRH increase
• Stimulates secretions of pituitary gland, producing gonadotropins
• This stimulates follicle development and estrogen secretions
• Estrogen induces changes in accessory sex organs, secondary sex characteristics

Question 4

What is menarche? What is primary/secondary menarche?

Answer 4

First period, this is a late events of puberty occurs around 12.5 years of age

• Primary, when a woman has no periods and has never had one
• Secondary, when a woman has had periods before but they have stopped (menopause in later life, eg 50)

Question 5

What is the effect of body weight on puberty?

Answer 5

• girls with low body weight may have late onset/no periods

- it is possible that adipose tissue leptin stimulates secretion of GnRH

Question 6

What occurs during puberty to girls?

Answer 6

-Growth spurt, maturation of skeleton
-Breast development
-

Question 7

What occurs during puberty to boys?

Answer 7

• Growth spurt, maturation of skeleton
• enlargement of genitalia
• pubic and axillary hair growth
• increase activity of hypothalamic anterior pituitary
• deepening of voice (larynx growth)
• thick secretion of skin oil glands (-acne)
• masculine pattern of fat distribution

(gonadal axis - increase gnRH, FSH, LH, seminerferous tubles, testosterone)

Question 8

How do hormonal contraceptives work?

Answer 8

Two main types

1. Progestogen/progestin and synthetic oestrogen - inhibits pituitary gland gonadotrophin release = prevents ovulation
2. “mini pill” - Progestogen/progestin
   affect the composition of cervical mucus so it is thick and cannot penetrate, also inhibit proliferation so that the uterus is inhospitable for implantation

Question 9

What changes to the breasts occur during puberty?

Answer 9

1. Increase in oestrogen stimulates duct growth and branching
2. Little development in alveoli
3. Mostly fat deposition
4. Increase in progesterone - stimulates alveoli growth
   (during each menstrual cycle breasts undergo small changes due to fluctuating levels of oestrogen and progesterone)