Endocrinology of reproductive system Flashcards
Where is FSH produced and what is it’s function?
follicle stimulating hormone
produced in anterior pituitary gland
acts on granulosa cells of ovary to stimulate follicle development
Where is LH produced and what is it’s function?
luteinising hormone
produced in anterior pituitary gland
acts on theca cells in ovary to cause ovulation
Where is oestrogen produced and what is it’s function?
produced in follicle in response to FSH
stimulates endometrial proliferation
responsible for development of secondary sexual characteristics
Where is progesterone produced and what is it’s function?
produced by granulosa cells in response to LH surge
triggers endometrial transition to secretory phase ie thickening of endometrium in preparation for implantation of fertilised egg
What happens in the follicular phase of the menstrual cycle?
FSH stimulates growth of several follicles
dominant follicle secretes oestrogen
oestrogen inhibits growth of other follicles and FSH
oestrogen stimulates development of endometrium
What happens in ovulation?
surge in LH causes ovulation (egg release)
rupturing of follicle creates a corpus luteum
What happens in the luteal phase of the menstrual cycle?
corpus luteum secretes progesterone (and oestrogen)
progesterone stimulates development of endometrium
oestrogen and progesterone inhibit FSH and LH
corpus luteum degrades over time
when corpus luteum degrades, progesterone levels drop
without progesterone, endometrium cannot be maintained
endometrium is sloughed away (menstruation)
no longer inhibited, FSH can start menstrual cycle again
if fertilisation of egg occurs, the zygote releases a hormone (hCG) which maintains the corpus luteum
Common presenting features of reproductive endocrine conditions in women
oligo/amenorrhoea
infertility
hirsutism
virilisation (male physical characteristics in a woman)
hot flushes, night sweats
galactorrhoea
Define primary amenorrhoea
no periods by 16
Define secondary amenorrhoea
no periods for >6 months in a woman who has previously had a period
Define oligomenorrhoea
<9 periods in a year
Define infertility
failure of pregnancy after 1 year of regular unprotected intercourse
Physiological amenorrhoea causes
pre-pubertal
pregnancy
lactation
menopause
Primary amenorrhoea causes
chromosomal (eg. Turner’s)
hypothalamic-pituitary failure
vaginal outflow tract and uterine disorders
Secondary amenorrhoea causes
ovarian - PCOS, primary ovarian failure
hypothalamic - weight loss, excessive exercise, stress, craniopharyngioma, hypothalamic lesions
pituitary - hyperprolactinaemia, hypopituitarism
uterine -intrauterine adhesions, Asherman’s syndrome
other endocrine disorders - thyroid dysfunction, Cushing’s, congenital adrenal hyperplasia
What are the 3 male reproductive hormones?
follicle stimulating hormone
luteinising hormone
testosterone
FSH function in men
stimulates sperm development
LH function in men
acts on interstitial cells (Leydig cells) to secrete testosterone
Testosterone function in men
promotes sperm development and development of secondary sex characteristics
Testosterone target organs and function
skin - facial + body hair growth, supports collagen
male sex organs - sperm production, prostate growth, erectile dysfunction
muscle - muscle mass and strength
brain - sex drive, positive feelings, aids cognition and memory
bone marrow - red blood cell production
bone - bone density maintenance
Common presenting features of reproductive endocrine conditions in men
absence or regression of secondary sexual characteristics
sexual dysfunction (erectile dysfunction, reduced libido, difficulty attaining orgasm + reduced ejaculate)
reduced energy, muscle wasting, reduced bone mass, osteoporosis
infertility
Primary hypogonadism hormone levels (men)
high FSH, LH
low Testosterone
Secondary hypogonadism hormone levels (men)
low FSH, LH
low testosterone
What is primary hypogonadism?
testicular failure
