Sex Steroids Flashcards
(27 cards)
Describe GnRH
From - Hypothalamus
Synthesis and secretion of LH and FSH
Describe FSH
From - AP
Follicle growth and oocyte maturation
Describe LH
From - AP
Stimulates ovulation and causes the ruptured follicle to become the corpus luteum
Describe oestrogen
From - Maturing follicle
Repair and growth of endometrium
Feedback inhibitor for FSH and LH
Describe progesterone
From - Corpus luteum
Prepares endometrium for implantation
Promotes growth of mammary glands
Feedback inhibitor for FSH and LH
What are the sex steroid hormones?
Oestradiol
Progesterone
Testosterone
What are sex steroid synthesised from?
Cholesterol
Briefly outline sex steroid synthesis
Starts with cholesterol
Involves CYP17 and aromatase
What are the actions of oestrogen?
Mild anabolic
Sodium and water retention
Raises HDL, lowers LDL
Decrease bone resorption
Impair glucose tolerance
Increase blood coagulability
What are the side effects of oestrogen?
Breast tenderness
Nausea, vomiting
Water retention
Increased blood coagulability
Thromboembolism
Impaired glucose tolerance
Endometrial hyperplasia + cancer
Ovarian metaplasia + cancer
Breast hyperplasia + cancer
What are the actions of progesterone?
Secretory endometrium
Anabolic
Increases bone mineral density
Fluid retention
Mood changes
Maintains pregnancy
What are the side effects of progesterone?
Weight gain
Fluid retention
Anabolic
Acne Nausea/vomiting
Irritability
Depression, PMS
Lack of concentration
Outline the actions and side effects of testosterone
Male secondary sex characteristics
Anabolic
Acne
Voice changes
Increases aggression
How can contraceptives be administered?
Oral – oestrogens, progestins
Transdermal patch
Implants
Nasal
Vaginal
How is progesterone effected by the liver?
It is almost totally metabolised in one passage through liver
What types of oral contraception are available?
COCP = oestrogen + progestin
POP = progestin only
Describe the mode of action of an oral contraceptive pill
Suppression of ovulation – inhibits FSH + LH
Makes cervical mucus more viscous = prevents sperm entering
Prevents secretory phase of the endometrium – remains atrophic = prevents implantat
What are the adverse effects from taking the OCP?
Venous thromboembolism
Myocardial infarction
Hypertension – swap to the progestin only pill
Decrease glucose tolerance
Increase risk of stroke in women with focal migraine
Headaches
Mood swings
Cholestatic jaundice
Increase incidence of gallstones
Precipitate porphyria
How does the liver effect the COCP?
Metabolised by CYP450
Efficacy therefore reduced by enzyme inducing drugs (carbamazepine, rifampicin)
What is the mini-pill
Progestin only
28 days
Effects cervical mucous and the endometrium
Briefly outline missed pill advice
Take last pill immediately, even if taking 2 in 1 day
Take the rest of the pack as normal
If more than 2 pills missed = use extra contraception for 7 days
Why is HRT prescribed?
Symptoms = hot flushes, sweats, vaginal dryness
Osteoporosis
What are the risks of HRT?
Unopposed oestrogen (ERT): risk of devel endometrial and ovarian cancers
Opposed oestrogen (HRT): risk of devel breast cancer
Increased risk of stroke and ischaemic heart disease
Increased risk of venous thromboembolism
How can HRT be administered?
Oral
Transdermal
Implant
Transvaginal
Nasal
