Sex Hormones I Flashcards
(30 cards)
What is puberty?
Process of physical changes making the body capable of sexual reproduction:
1. maturation of reproductive organs
2. sex steroid production (oestradiol and
testosterone)
3. secondary sexual characteristics develop
- females onset 8-13 yo
- males onset 9-14 yo
What is Tanner Staging?
Method to track progression of puberty
- 5 stages
- females —> thelarche (1st sign)
—> pubarche
- males —> testicular volume
- measure via prader orchidometer
- prepubertal —> <4ml
adult —> >15ml
—> pubarche
What is gonadarche?
Onset of HPG axis activation
- measure via FSH/LH/oestrogen/testosterone
production
What is thelarche?
Onset of breast development
- first sign of puberty —> age 11
- stage 2 —> age 11-12
3 —> 12
4 —> 13
5 —> 14-15
What is menarche?
Onset of menstrual cycle
- last sign of puberty —> age 14-16 (mean 12.7)
- 2.3 years after thelarche
- soon after PHV (peak height velocity)
What is spermarche?
Onset of spermatogenesis
- onset 15-16 yo —> stage 4
What is adrenarche?
Onset of adrenal androgen production
- measure via DHEAS/DHEA production
- females - 6-9 yrs
- males - 7-10 yrs
- more important in females ∵ males —> testes
produce testosterone
What is pubarche?
Onset of pubic hair
- females:
stage 2 —> age 11-12
3 —> 12-13
4 —> 13
5 —> 14-15
- males:
stage 2 —> age 12-13
3 —> 14
4 —> 14-15
5 —> 16
What are the female secondary sexual characteristics? (4)
- Breast development
- Hair growth —> pubic
—> axillary - Sweat gland compositions —> oily skin
—> acne - External genitalia changes
What are the male secondary sexual characteristics? (4)
- Voice deepens
- Hair growth —> pubic
—> axillary
—> facial - Sweat gland compositions —> oily skin
—> acne - External genitalia changes
What is the sequence of pubertal events in females?
- Adrenarche —> 6-9 yo
- Growth spurt —> 11-13 (stage 2-3)
- Thelarche —> 11-15 (stage 2-5)
- Pubarche —> 11-15 (stages 2-5)
- Menarche —> 14-16 (stage 5)
What is the sequence of pubertal events in males?
- Adrenarche —> 7-10 yo
- Thelarche —> 12-16 (stage 2-5)
- Pubarche —> 12-16 (stages 2-5)
- Growth spurt —> 14-16 (stage 3-4)
- Spermarche —> 15-16 (stage 4)
What is the mini puberty?
HPG-axis first activated in late-foetal life
- not reactivated till puberty
- males —> till 6 months old
females —> till 2 years old
- effects —> testicular descent
—> penile length
—> sertoli cell maturation
—> behaviour
What is precocious vs delayed puberty?
Precocious —> early puberty
- females - onset <8 yo - more common than males
Delayed —> late puberty
- males - onset >14 yo - more common than females
What is amenorrhea vs oligomenorrhea?
Amenorrhea = no period
- primary —> don’t start after age 16
- secondary —> start then stop
- stop for 3-6 months
- <3/year
Oligomenorrhea = few periods (frequent/irregular)
- >35 day cycles
- 4-9 cycles/year
What occurs during the follicular phase of the menstrual cycle?
- FSH rises —> 2-3 follicles start to grow
- Follicles produce E2 (oestradiol) + inhibin B —> dec
FSH via -ve feedback - Restricted ‘FSH window’ —> atresia of non-
dominant follicles —> only 1 egg/month - High E2 —> switch to +ve feedback —> LH inc
(causes ovulation on day 14)
What occurs during the uterine cycle?
Menstrual phase —> endometrium sheds
Proliferative phase —> endometrial lining grows
(oestradiol) - new epithelial cells
- gland proliferation
- inc stroma and arterioles
Secretory phase —> receptive for implantation
(progesterone) - inc stomal cells —> thick/spongy
- cork-screw glycogen glands
- spiral arteries coil + lengthen
What happens in to the corpus luteum at the end of the menstrual cycle?
Fertilised - B-hCG maintains corpus luteum —>
secretes more progesterone and oestrogen
Not fertilsied —> degrades to corpus albicans
How does GnRH secretion change throughout the menstrual cycle?
Follicular phase —> pulsatile every 90-120 mins
Luteal phase —> pulsatile every 180-240 mins
(continuous non-pulsatile GnRH would result in dec LH/FSH)
What is hypogonadism?
Female —> low oestrogen
Male —> low testosterone
- HPG axis inhibited
What is primary hypogonadism?
Hypogonadism due to gonad issue
- males —> infection
—> testicular trauma
—> testicular cancer
females —> menopause
- dec oestrogen/testosterone
inc LH/FSH levels ∵ pituitary —> dec -ve feedback
What is secondary hypogondaism?
Hypogonadism due to pituitary issue
- male/female —> pituitary tumour
—> high prolactin
- dec oestrogen/testosterone
dec LH/FSH levels ∵ pituitary —> dec -ve feedback
What is menopause?
When a female has naturally lost all of their eggs
- physiological primary hypogonadism —> dec E2
- peri-menopausal —> before menopause
post-menopausal — >1 year after
- onset —> 45-55 yo
- <45 —> premenopause
- <40 —> premature —> POI
Symptoms:
- skin dryness/hair thinning
- hot flushes/sweating —> disturb sleep
- mood changes
- osteoporosis + joint pain (dec BMD)
- sexual dysfunction (vaginal dryness, low libido)
- frequent UTIs (genitourinary disturbance)
- weight gain
- amenorrhoea
- infertile
How are menopausal symptoms treated?
MHT = Menopausal Hormone Therapy
- give oestrogen —> endometrium proliferation
and progesterone —> prevent endometrial
hyperplasia/cancer
