Sex hormones during life Flashcards
What is the first sign of puberty in females?
Thelarche- breast development
What happens in thelarche?
- Elevation of papilla only
- Breasts bud with elevation of breasts and papilla and enlargement of areola
- Further enlargement of breasts and papilla with no separation of their contours
- Projection of areola and papilla to form a secondary mound
- Mature breast, projection of papilla only as areola conforms to breast contour
What is the first sign of puberty in males?
Genitalia- testicular volume in boys
How does genitalia develop in boys?
- Testes, penis and scrotum same size as early childhood
- Early enlargement of testes 2-6cm^3, scrotal skin reddens and changes in texture
- Penis lengthens, testes enlarge 6-12cm^3 , growth of scrotum
- Further penile and scrotal growth, testes 12-15 cm^3
- Genitalia adult in size and shape, testes >15cm^3
What is the development of pubic hair called?
Pubarche
What occurs in pubarche?
- Vellus hair no different from abdominal hair
- Slightly pigmented downy hair
- Darker, courser, more curled hair
- Adult pubic hair that does not reach thighs (Axillary hairs)
- Adult hair now on thighs
What are terms that end in ‘-arch’ and what do they mean?
Gonadarche- activation of gonads by HPG axis Menarche- menstrual cycle activation Spermarche- spermatogenesis Adrenarche- adrenal androgen production Pubarche- pubic hair development Thelarch- breast development
What are secondary sexual characteristics in females?
Oestrodial: Breast development Hair growth Sweat gland composition- skin oiliness/ acne Changes to external genitalia
What are secondary sexual characteristics in males?
Testosterone: Deepening of voice Hair growth Sweat gland composition Changes to external genitalia
What hormonal changes occur in females throughout puberty?
Increased FSH and LH
What hormonal changes occur in males throughout puberty?
Increased testosterone
Before what age is puberty early?
8 years
After what year is puberty delayed?
14 years
What do we call a lack of periods?
Primary amenorrhea: no period by 16 years
Secondary amenorrhea: periods start then stop for 3-6 months
Oligoamennorhea: few periods, irregular or infrequent cycles (4-9 cycles per yr)
What are the stages of menstruation?
- Follicular phase:
- small rise in FSH
- 2-3 follicles grow . Produce E2 (oestrodial) and inhibin B
- these reduce FSH through neg. feedback
- Restricts FSH window and non-dominant follicles undergo atresia - Ovulation:
- A dominant ‘ Graafian’ follicle emerges
- E2 continues to increase
- Switch to high E2 (positive feedback) - Luteal phase
- corpus Leuteum made which produces progesterone and oestrogen
How does GnRH pulsitility change duding menstruation?
In the luteal phase you get slowing of pulses
Continuous non-pulsatile administration of GnRH leads to decreases FSH and LH secretion
What is hypogonadism?
Decreased oestrogen in a woman/ degreased testosterone in a male
What is primary hypogonadism?
Problem with testes or ovaries
Negative feedback is lost and rise of FSH and LH
What are causes of primary hypogonadism?
Males: Infection of testes, trauma, cancer
Females: menopause
What is secondary hypogonadism?
Problem with pituitary
low/ normal LH/FSH but low E2/testosterone
What are causes of secondary hypogonadism?
Pituitary tumour
What occurs in menopause?
Lack of negative feedback from oestrodial to hypothalamus and pituitary
Low E2, high FSH/LH, low inhibin
What are symptoms of menopause?
Skin dryness Thin hair Hot flushes/ sweating Sleep disturbances Mood disturbances Osteoporosis Sexual dysfunction Weight gain Amenorrhea Climateric- irregular periods in the years approaching menopause
What is treatment for menopause?
Oestrogen replacement- HRT (hormone replacement therapy)
Add progesterone
What is an ovarian reserve marker?
Anti- mullein hormone (Sertoli cell)
Are there andopauses in males?
After ~50 yrs testosterone decreases by about 1% each year
Late onset hypogonadism is menopause for men
What is early menopause called?
Premature ovarian insufficiency
Conception can happen in 20%
Diagnosis is high FSH
Causes: autoimmune, cancer therapy
What is testosterone bound to?
60% is SHGB bound testosterone
38% is albumin bound
2% is free testosterone- has effect in tissues
When should testosterone be measured?
Testosterone has diurnal rhythm so should be measured before 11am
What are symptoms of testosterone deficiency?
Sexual dysfunction- reduced libido, erectile dysfunction
Hair growth
Energy levels- fatigue
Mood disturbance
Body composition- increased fat/ reduced muscle mass
Spermatogenesis - high levels of intratesticular testosterone needed
Bone health
What can testosterone be converted to?
Can be converted to oestrogen by age, obesity, insulin, gonadotrophin, alcohol with aramotase
Can be converted to di-hydro-testosterrone by 5 alpha reductase
