Sex hormones Flashcards
What is the definition of puberty
Maturation of reproductive organs Production of sex steroids Development of secondary sexual characteristics Attain capability to reproduce
What is thelarche
Breast development
What is genitalia
What is pubarche
What are the different types of arche
Gonadarche - activation of gonads
Thelarche - breast development
Menarche - menstural cycles
Spermarche - spermatogensis
Adrenache - Adrenal Androgen Production
Pubarche - Pubic hair
What are the secondary sexual characteristics in girls
Breast development
Hair growth - pubic, axillary
Sweat Gland Composition - skin oiliness/acne
Changes to external genitalia
What are the secondary sexual characteristics in men
Deepening of voice
Hair growth - pubic then axillary, facial
Sweat Gland Composition - skin oiliness/acne
Changes to external genitalia
Sequence of pubertal events in girls
Thelarche
Pubarche
Height
Menarche
Sequence of pubertal events in guys
Gonadarche
Pubarche
Onset penis growth
Height
Is normal Gonnadotrophin releasing hormone secretion pulsatile
Yes
Hormonal Control of Puberty-Gonadarche
What are the normal age of puberty
Girls 8-13yrs
Boys 9-14yrs
S.d. SD
What are the features of menarche
Happens 2.3 years after thelarche
Primary amenorrhoae - later than 16 years is abnormal
Secondary amernorrhoea - periods can be irregular. Classified as stopping for 3 to 6 months
What is a-menorrhoea
Absence of periods
3-6 months no periods
What is oligo-menorrhoea
Few periods
Infrequent periods with >35 days
4-9 cycles per year
What is the follicular phase of menstrual cycle
- FSH rises
- 2-3 follicles grow
- Produces E2 and Inhibin B
- Reduce FSH (negative feedback)
- Restrict FSH window and non dominant follicles undergo atresia
- Dominant graafian follicle is less FSH dependent
- E2 continues to increase
- Switches to +ve feedback
- Induces LH surge
- Ovulation
What happens during the luteal phase of ovarian cycle
Corpus luteum forms
Progesterone and oestradiol
What happens during the secretory phase - uterine cycle
Increased volume of stromal cells
Cork-screw shaped glands secreting glycogen
Coiling and lengthening of spinal arteries
What happens during the proliferative pahse
Growth of new epithelial cells
Gland proliferation
Increase/ arterioles
What happens when there is non-pusaltility of the HPG axis
Decreased LH/FSH secretion
What is the difference in pulsatility in follicular compared to luteal
Follicular phase - every 90-120 minutes
Luteal phase - 180-240 minutes
What is hypogonadism
Decrease Oestrogen in a woman
Decreased Testosterone in a man
What happens in primary hypogonadism
Low E2/testo
High LH/FSH
Men - infection, trauma, cancer of tests
Women - menopause
What happens in secondary hypogonadism
Pituitary Tumour
High Prolactin
Low LH/FSH
Low E2/Testo
What are the symptoms of menopause
Skin dryness/ hair thinning
hot flushes/ sweating/ sleep disturbance
Mood disturbance
Oestoporosis
Sexual Dysfunction
Weight gain
Amenorrhoea - peri, within 1yr of LMP: post - after 1yr LMP
Cessation of fertility
Climateric - irregular periods
What is the treatment of menopause
Oestrogen Replacemnt - HRT
Oestrogen stimulates the endometrium
Add progesterone if endometrium is intact to prevent endometrial hyperplasia/ cancer
What does ovarian reserve refer to
Number of eggs in ovaries that you can have before menopause
What hormone can you detect for ovarian reserve
Anti mullerian Hormone
Produced by granulosa cells in ovaries
What is the average age of menopause
45-55
51
How to diagnosis someone with premature ovarian isuffiency
FSH >25 iU/L on two occasions
What are causes of premature ovarian insuffiency
Autoimmune
Genetic - fragile X syndrome/ Turners syndrome
Chemotherapy
What is the percentage of testosterone in the blood
60% is bound to sex hormone binding globulin - extremely strong so unavaliable
38% Albumin - weakly binds, bioavaliable
2% active - free testosterone
What is andropause
SHBG increase which decreases free testosterone
Lat onset hypogonadism
When is testosterone at its peak
Measure testosterone at its peak
Diurnal rhythm
How does sugar affect testosterone
Drop testosterone by 20%
Measure it when fasting
What are symptoms of testosterone deficiency
Sexual dysfunciton
Decrease frequency of hair growth
Energy level
Mood disturbance
Increase fat/ reduced muscle mass
Gynaecomastia (breast enlargment)
Decrease spermatogenesis
Oestoperosis
What converts testosterone to dihydrotesterone
Stronger androgen, more potent ligand for AR
5alpha - reductase
Prostate, Skin, Liver, Testes
What converts testosterone to oestrogens
Armotase
Adipose tissue
Adrenal glands
Ovaries
Testes
Brain
Bone Skin
What increases aromatase
Age
Obesity
Insulin
Gonadotrophins
Alcohol
What does aromatase convert
Androstenedione - oestrone
Testosterone - 17B oestradiol
How can you use enzymes therapeutically
Aromatase inihibtor - anastrozole for breast cancer
5 alpha reductase inhibitor - finasteride
