Ovulation disorders and male hypogonadism Flashcards Preview

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Flashcards in Ovulation disorders and male hypogonadism Deck (91):
1

Briefly describe the hypothalamic-pituitary-gonadal axis

Hypothalamus secretes gonadotrophin releasing hormone >
GnRH acts upon the anterior pituitary >
Anterior pituitary secretes LH and FSH >
LH and FSH stimulate gamete formation (FSH only in males) directly and via the production of steroid and peptide hormones within the gonads

2

What type of hormones are oestrogens?

Steroid

3

Where and by which cells does glandular oesteogen synthesis occur?

Ovaries - theca and granulosa cells
Corpus luteum

4

Which type of cells does LH stimulate? Which hormone production does it induce?

Granulosa
Pregnenolone

5

Describe the process of oestradiol production

Pregnenolone diffuses form the granulosa cells to theca cells >
Theca cells convert pregnenolone to androstenedione using 17,20-lyase and 3beta-HSD >
Androstenedione returns to the granulosa cells where it is converted to oestrone by aromatase >
Oestrone is further converted to oestradiol by 17beta-HSD

6

What does FSH do? How does it do this?

Stimulates the conversion of androstenedione to oestrone via aromatase
Stimulates the conversion of oestrone to oestradiol via 17beta-HSD

7

Where and how does extra-glandular oestrogen synthesis occur?

Aromatase expression in fat and bone allows conversion of androstenedione to oestrone

8

Explain progesterone synthesis

3beta-HSD converts pregnenolone to progesterone in the corpus luteum, placenta (during pregnancy) and adrenals (pathway to androgen and mineralocorticoid synthesis)

9

What receptors numbers increase in the presence of oestrogen?

Intracellular progesterone receptor

10

How do the products of hormone synthesis vary with the menstrual cycle?

Follicular phase - oestradiol
Luteal phase - progesterone

11

When are LH and FSH highest?

Just before and during ovulation

12

What does oligomenorrhea mean?

Less than 9 periods a year

13

What does primary amenorrhea mean?

Failure of menarche before age 16

14

What does secondary amenorrhea mean?

Cessation of periods for over 6 months in an individual who has previously menstruated

15

What categories do the causes of amenorrhea fall under?

Physiological
Primary (genetic)
Secondary (ovarian, uterine, hypothalamic, pituitary)

16

How should amenorrhea be investigated?

LH/FSH
Oestradiol
Thyroid function
Prolactin

Ovarian ultrasound
Testosterone
Pituitary function
MRI
Karyotype

17

What is female hypogonadism?

Low levels of oestrogen

18

Where does the problem lie with primary and secondary hypogonadism respectively?

Primary - ovaries
Secondary - hypothalamic or pituitary

19

What is hypergonadotrophic hypogonadism?

Low oestradiol
High FSH/LH

20

What is hypogonadotrophic hypogonadism

Low oestradiol
Low FSH/LH

21

What is premature ovarian failure?

Amenorrhea, oestrogen deficiency and elevated gonadotrophs occurring before the age of forty

22

What is the diagnostic criteria for premature ovarian failure?

FSH > 30 on two separate occasions at least 1 month apart

23

What are the causes of premature ovarian failure?

Chromosomal
Genetic mutation (FSH/LH receptor)
Iatrogenic
Autoimmune

24

What are the chromosomal causes of premature ovarian failure?

Turner's
Fragile X

25

What are the iatrogenic causes of premature ovarian failure?

Surgery
Radiation

26

What are the autoimmune causes of premature ovarian failure?

Addison's
Thyroid disease

27

What is kallman's syndrome a problem with?

Hypothalamus

28

Wilson's syndrome can cause hypogonadism. T/F

False - haemochromatosis

29

What is idiopathic hypogonadotrophic hypogonadism?

Absent/delayed sexual maturation with low gonadotrophs in the absence of anatomical or functional problem with the hypothalamic-pituitary-gonadal axis

30

Where is the problem with idiopathic hypogonadotrophic hypogonadism?

Hypothalamus - inability to activate GnRH secretion

31

There are a number of genetic defects associated with idiopathic hypogonadotrophic hypogonadism. T/F

True - GnRH secretion is pretty complex

32

What is the role of kisspeptin in the regulation of GnRH production?

Kisspeptin binds to the KISS1P gene to induce GnRH secretion

33

What are the effects of kisspeptin?

Gatekeeper of puberty
Regulator of male and female fertility
Involved in feedback control of oestrogen and therefore menstruation and ovulation

34

What is Kallman's syndrome?

A genetic disorder causing the loss of GnRH secretion and anosmia/hyposmia due to failure of hypothalamic migration

35

How is the pituitary affected in Kallman's syndrome?

Normal apart from reduced LH/FSH due to lack of stimulation from GnRH

36

What does a brain MRI show in Kallman's syndrome?

Normal pituitary
No olfactory bulbs

37

Which sex is affected by Kallman's most often?

Male

38

Is Kallman's associated with a family history or nah?

Sometimes

39

How can you differentiate between Kallman's syndrome and idiopathic hypogonadotrophic hypogonadism?

Presence or absence of anosmia

40

How are the hormone levels affected in pituitary dysfunction?

Low/normal LH/FSH
Low oestradiol

41

What causes of pituitary dysfunction can cause hypogonadism?

Non-functioning adenoma
Pituitary infarction
Prolactinoma
Dopamine antagonists

42

What are the causes of hyperprolactinemia?

Prolactinoma
Pituitary pathology
Anti-psychotics
Dopamine antagonists
Hypothyroidism
Idiopathic

43

What are the ovarian causes of amenorrhea?

PCOS
Ovarian failure
Congenital problem

44

What is the rotterdam criteria for PCOS?

Menstrual irregularity
Hyperandrogenism
Polycystic ovaries
(>2/3)

45

What are the signs of hyperandrogenism?

Hirsutism
Elevated free testosterone

46

What types of congenital problems can cause amenorrhea?

Absent uterus
Vaginal atresia
Turner's
Testicular feminisation
Congenital adrenal hyperplasia

47

Describe the pathophysiology of polycystic ovarian syndrome?

Genetic predisposition to excess androgen secretion >
Increased testosterone >
Hirsutism ; increased LH ; insulin resistance + hyperinsulinaemia >
Increased LH & hyperinsulinaemia further increase testosterone and cause anovulation ; hyperinsulinaemia causes the liver to secrete less sex hormone binding globulin propagating hirsutism

48

What is hirsutism?

Excess hair in the male pattern distribution in females

49

What causes hirsutism?

Excess androgen at hair follicles caused by increased circulating androgen and increased peripheral conversion at the hair follicle

50

Where is androgen synthesised?

Ovaries and adrenals

51

What are the causes of hirsutism?

PCOS
Familial
Idiopathic
Non-classical adrenal hyperplasia
Adrenal tumour
Ovarian tumour

52

How can adrenal/ovarian tumours causing hirustism be differentiated from other causes?

Tumours - short history, virilisation
Other causes - long history, testosterone not crazy high, no virilisation

53

What is virilisation?

Deep voice
Clitomegaly

54

What is congenital adrenal hyperplasia?

Group of genetic disorders causing a deficiency in an enzyme essential for cortisol synthesis

55

What is the most common enzyme responsible for congenital adrenal hyperplasia?

21 alpha hydroxylase

56

Is congenital adrenal hyperplasia dominant or recessive?

Recessive

57

When is classical CAH diagnosed?

Infancy

58

When is non-classical CAH diagnosed?

Adolescence or adulthood

59

How does classical and non-classical CAH present respectively?

Classical - virilisation, salt-wasting
Non-classical - hirsutism, menstrual disturbance, infertility

60

What should be particularly elevated in CAH after synacthen?

Progesterone (ACTH drives androgen production)

61

How do androgen secreting tumours present?

Short history
Virilisation
Testosterone >5mmol/l

62

What can be done to investigate a suspected androgen secreting tumour?

MRI adrenals and ovaries

63

How is PCOS treated?

Oral contraceptive pill
Anti androgens (cyproterone acetate)
Local anti-androgens (efflornithine cream)
Cosmesis (laser, electrolysis)

64

How is non-classical CAH treated?

Low dose glucocorticoid

65

What is the chromosomal abnormality in Turner's syndrome?

Only one X chromosome

66

Which sex is affected by turner's syndrome?

Females

67

How does turner's syndrome present?

Short stature
Webbed neck
Shield chest w/ wide spaced nipples
Cubitus valgus

68

What is XX gonadal dysgenesis?

Absent ovaries with no chromosomal abnormality

69

What is testicular feminisation/androgen insensitivity syndrome?

Genetically XY but phenotypically female (pseudohaemaphrodite)

70

What is primary male hypogonadism?

Low testosterone
High LH/FSH

71

What is secondary male hypogonadism?

Low testosterone
Low LH/FSH

72

What are some causes of primary hypogonadism?

Congenital
Acquired (cirrhosis, testicular trauma, radiation, mumps, etc)

73

What aspects of a history are important to cover in male hypogonadism?

Sexual function (libido, erections & ejaculation)
Age of puberty
Fertility
Symptoms of pituitary disease
Duration of symptoms

74

What signs may be found in male hypogonadism?

Lower than expected stage of puberty
Small testicular volume
Features of pituitary disease (e.g visual field defects)

75

How should male hypogonadism be investigated?

Testosterone (free and total)
LH & FSH

76

What is klinefelter's syndrome?

Congenital form of primary hypogonadism caused by chromosomal abnormality XXY

77

Which sex is affected by klinefelter's syndrome?

Male

78

What are the features of klinefelter's?

Reduced testicular volume
Gynecomastia
Eunuchoidism
Intellectual dysfunction
Azoospermia

79

How should klinefelter's syndrome present biochemically?

Low testosterone
High LH/FSH
High sex hormone binding globulin
High oestradiol

80

What are the causes of secondary male hypogonadism?

Hypothalamic
Pituitary

81

When should testosterone level be measured?

9am

82

What are the congenital causes of secondary male hypogonadism?

Idiopathic hypogonadotrophic hypogonadism
Kallman's
Congenital adrenal hyperplasia

83

When is testosterone therapy indicated?

Hypogonadism in young men (>50 seek specialist advice)

84

Does testosterone therapy restore fertility?

No. May even act as a contraceptive

85

What are the benefits of testosterone therapy?

Improved sexual function (young > old)
Improved bone health (IM > transdermal)
Improved muscle strength and decreased fat
Minimal affect on diabetes

86

How does gynecomastia result?

Increase oestrogen effect on breast tissue

87

What are the causes of gynecomastia?

Physiological
Spironolactone
Digoxin
Hypogonadism
Adrenal tumours
Testicular tumours
Endocrine pathology (thyrotoxicosis, cushing's)
Systemic illness
Hereditory disorders

88

Which aspects of a history are important in gynecomastia?

Duration
Pain
Hypogonadism
Systemic illness
Drugs
Alcohol

89

Which aspects of an examination are important in gynecomastia?

Breast tissue vs fat
Unilateral vs symmetrical
Lumps
Testicular examination
General examination (liver disease)

90

How should gynecomastia be investigated?

Testosterone
LH/FSH
Oestradiol
Prolactin
AFP/HCG
LFT
SHBG
Breast imaging
Adrenal imaging
Testicular imaging

91

How is gynecomastia treated?

Underlying cause
Reassurance
Cosmetic surgery
Medication (anti-oestrogens)

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