Neuroendocrine Timing Of Puberty Flashcards
Define puberty.
Preparation for sexual maturity, to enable us to reproduce. Creating sexual dimorphism.
Which body weight is required for a girl to undergo puberty?
47kg.
Which scale is used to assess stages of puberty in boys and girls?
Tanner Scale.
Define Primary Sexual Characteristics.
Sexual characteristics at birth, before puberty has begun. This includes the internal and external genitalia.
Define Secondary Sexual Characteristics.
Characteristics that develop after puberty, such as pubic hair, breasts, genital development/enlargement and menstruation in females.
When do girls typically start puberty?
9-13 year old.
What is the order of events of puberty in a girl?
- Thelarche: breast bud development.
- Pubic hair: testosterone.
- Growth spurt: oestrogen fuse epiphyseal growth plate.
- Menarche: menstrual cycle.
- Pubic hair: coaster.
- Breast development.
When does puberty start in boys?
10-14 year old.
Describe the order of puberty in boys.
- Genital development: testicular volume enlargement.
- Pubic hair growth.
- Spermatogenesis.
- Growth spurt.
- Genital enlargement, increase in size.
- Pubic hair coarseness.
Describe the hormone control of puberty.
- Gonadotropin Releasing Hormone produced by hypothalamus. Caused initially by leptin. Pulsatile release.
- Luteinizing Hormone and Follicle Stimulating Hormone is released.
- Stimulate gonads to release androgens and oestrogen.
What do Sertoli cells do?
Produce sperm under the influence of FSH.
What do Leydig cells do?
Produce testosterone under the influence of LH.
What do Granulosa cells respond to?
FSH.
What do Theca cells respond to?
LH.
Is the Hypothalamic- pituitary axes a negative or positively controlled feedback?
Negative feedback mainly (men and women), positive feedback in women sometimes.
