Sex hormones Flashcards
Tanner staging for girls?
Breast development = Thelarche
Pubic hair development staging
What do the following mean?
- Gonadarche
- Thelarche
- Menarche
- Spermarche
- Adrenarche
- Pubarche
- Activation of gonads by HPG axis
- Breast development
- Menstrual cycles
- Spermarche
- Adrenarche
- Adrenal Androgen Production
- Pubic hair
- in girls if you lack adrenarche it can affect pubarche
Secondary sexual characteristcs due to Oestradoil?
-Breast Development
Hair Growth -
Pubic, Axillary
-Sweat Gland Composition -
Skin oiliness / Acne
-Changes to external genitaliaSecondary male sexual characteristics
Deepening of Voice
Hair Growth -
Pubic then Axillary, facial
Sweat Gland Composition -
Skin oiliness / Acne
Changes to external genitaliaWhat is the sequence of events of puberty in girls?
Thelarche
How does the hormonal Axis change through early life?
Neonatal - GnRH is secreted ( mini-puberty )
Low during childhood
Increases through puberty ( pulsatility increases nocturnally )
During adult life normal pulsatile GnRH secretion
What is precocious or delayed puberty?
Early puberty before 8 ( common in girls )
After 14 ( common in boys )
What is precocious or delayed puberty?
Early puberty before 8 ( common in girls )
After 14 ( common in boys )
What are the characteristics of Menarche during puberty?
2.3 years after thelarche
Soon after peak height velocity (PHV)
What is Primary Amenorrhoea?
Not starting periods
Later than 16 years is abnormal
What is secondary Amenorrhoea?
no periods for 3-6 months or up to 3 a year
Periods can be irregular
Periods can start but then stop
Oligo-menorrhoea?
Few periods
Irregular or infrequent
4-9 cycles a year
1 - Follicular phase of menstrual cycle?
FSH increases ( FSH window )
2-3 follicles start to grow ( dominant Graafian follicle with grow )
Estradiol E2 and inhibin B are produced
So FSH then decreases
- Smaller follicles which did not grow = death of the follicles and undergo atresia
What happens as Dominant Graafian follicle grows
Causes an increase of Oestradiol by positive feedback of high E2
This induces LH increase on day 14 = Ovulation
What does ovulation cause?
… corpus leteum?
Starts Luteal phase of progesterone increase for implantation and Oestradiol increase
What can we measure as evidence of ovulation taking place?
Midluteal D21 Progesterone
How to describe the cycle as Endometrium Uterine cycle?
Menstrual phase
Proliferative phase ( Oestradiol ) : Endometrial Lining regrows:
Growth of new epithelial cells Gland proliferation
Increase in stroma / arterioles
Secretory phase ( progesterone ): Transformation to be Receptive for Implantation:
Increased volume of stromal cells»_space;> thick spongy lining
Cork-screw shaped glands secreting glycogen
Coiling and lengthening of spiral arteries
What does Beta HCG do?
Once embryo implanted, released HCG
Receptors in corpus luteum, which then keeps releasing progesterone
What is the issue with continous non-pulsatile GnRH?
Decreased LH and FSH secretion
Pulsatility is relvent to menstrual cycle?
What is Hypogonadism?
Decreased Oestrogen in a Woman /
Decreased Testosterone in a Man
Characteristics of primary hypogonadism?
Problem with testes or ovaries
Reduced negative feedback
Causes in men : infection in testes, trauma, cancers
causes in women : menopause
Characteristics of secondary hypogonadism?
Pituitary tumour
Prolactinoma
- if LH/FSH was low and GnRH high it is also secondary
What is menopause?
Symptoms?
Lack of negative feedback = rise of LH/FSH
Low E2
Low Inhibin
Symptoms linked to lack of E2
-Skin Dryness / Hair Thinning
-Hot Flushes / Sweating / Sleep Disturbance
-Mood Disturbance
-Osteoporosis - Decr Bone Mineral Density (BMD)
(E2 stimulates osteoblasts)
-Sexual Dysfunction - Vaginal Dryness, Decreased Libido
-Weight gain
-Amenorrhoea – Peri- within 1yr of LMP, Post- after 1yr
Cessation of fertility
-Climacteric - Irregular periods in years close to Menopause
Menopause treatment?
-Oestrogen Replacement
HRT (Hormone Replacement Therapy)
-Oestrogen stimulates the endometrium
Add Progesterone - if Endometrium is intact to prevent risk of Endometrial Hyperplasia / Cancer
What is the Ovarian reserve?
What to test to predict?
Number of eggs in ovaries
Anti-Mullerian Hormone - Peaks in Early Adult life
Made in granulosa cells
What is Premature Ovarian Insufficiency (POI)
Same Symptoms as per Menopause
Previously called ‘Premature Ovarian Failure’ POF
Conception can happen in 20%.
Diagnosis High FSH >25 iU/L (x2 at least 4wks apart)
Causes
Autoimmune
Genetic eg Fragile X Syndrome / Turner’s Syndrome
Cancer therapy Radio- / Chemo-therapy in the past
Andropause?
late hypogonad…
Total Testosterone does not change but SHBG increases with age and so free testosterone is reduced
What is Free testosterone?
2% is free and active which manifests
38% Binds to Albumin - bioavailable
60% SHBG bound testosterone making it unavailable
What rhythm does testosterone have?
Diurnal Rhythm
Higher in morning so measure before 11am
Lowers with sugar
Symptoms of testoesterone deficiency?
Sexual Dysfunction - Reduced Libido (sexual desire)
Erectile Dysfunction»_space; loss of Early Morning erections
Hair Growth - Frequency of Shaving?
Energy levels - General Well-being, Fatigue.
Mood Disturbance
Body Composition - Increased Fat / reduced Muscle Mass Gynaecomastia (breast enlargement in man)
Spermatogenesis - High levels of Intratesticular testosterone needed
Bone health - (Via conversion to oestrogen)
What does 5 alpha reductase do?
Converts testosterone to Di-Hydro Testosterone as a really strong androgen. Binds to receptors and can cause baldness
Can use a inhibitor for enzyme e.g. Finasteride to tackle prostate cancer
What does Aromatase do?
Convertes Testosterone to Oestrogens
Age, Obesity, Gonadotrphins, Alcohol increases Aromatase. So can reverse actions, can give Aromatase inhibitor e.g. breast cancer
