Repro 3 Flashcards
What is thelarche?
Development of the breast
What is puberache?
Development of axillary and pubic hair
Menarche?
The first mestrual period
Adrenarche?
The onset of an increase in the secretion of androgens
Define puberty
A stage of human development during which sexual maturation and growth are completed, resulting in the ability to reproduce
When are primary sexual characteristics established?
Before birth
Which hormones are most associated with, and rise at the onset of, puberty?
Hint: 3
GnRH, LH&FSH
Why are the functioning parts of the reproductive system not active before puberty?
GnRH levels are too low
Why do men tend to be larger than women?
The male growth spurt is usually longer and faster. It also happens later in boys
What stops the growth spurt and which hormone is responsible for it in girls?
Closing the epiphyseal growth plates
Osetrogen
What is happening to the timing of puberty and why?
It is occurring sooner due to better nutrition
The critical weight for puberty to start (47kg in girls) is reached earlier
What supports the idea of critical weight relating to puberty?
Malnutrition associated with delayed menarche
Primary amenorrhoea common in lean femal athletes
Which gland can influence puberty timings in humans and why?
The pineal due to its role in regulating circadian rhythym using melatonin
What, then, can a pineal tumour cause?
Precocious puberty
Wha does a rise in gonadotrophins lead to?
Secretion of sexual steroids i.e. oestrogens and androgens
What are the first two substances involved in the hormonal changes of puberty?
Neurokinin B, which promotes production of Kiss 1 neuron arcuate, which in turn increases secretion of GnRH
Which hormone, secreted from the pituitary, influences the growth spurt and how?
Growth hormone, by increaseing TSH secretion and thereby metabolic rate
What precedes the phenotypic changes of puberty?
Nocturnal GnRH pulsality causing LH secretion
What are the first phenotyppic changes of puberty?
Males -testicular enlagrement
Females - breast development?
What does the increased nocturnal LH lead to?
Nocturnal rise in testosterone in males and oestrogen in femaled leading to early pubertal changes
When do FSH&LH levels rise in males and what happens at the same time?
~10years
spermatogenesis and growth of sexual characteristics structures e.g. prostate from androgen secretion
What hormone induces some of the secondary sexual characteristics in females and what are they ?
Oestrogen - growth of pelvis, deposition of subcutaneous fat and growth of internal reproductive organs as well as external genitalia
What is used to classify the stages of pubertal development?
The Tanner standard - 5 stages
What are the stages of the Tanner standard for males?
Testicular volume - >4ml Penis enlargement - G 1-5 Pubic hair - Pu 1-5 Axillar yhair - A 1-5 Spermarche
How many times greater is the velocity of growth during puberty?
2-3
When does puberty start in males and females?
Males - 10-14
Females - 9-13
What is the first sign of puberty in males and females?
Males - testicular volume 4ml
Females - B2
What are the stages of the Tanner standard for females?
Breast - B 1-5
Pubic hair - Pu 1-5
Axillary hair - A 1-5
Menarche
What initiates the first ovarian cycle?
LH surge
Despite the ovarian cycle begininning, what does not happen during the first and why?
Ovulation - insufficient LH
Define precocious puberty
When puberty occurs younger than 2SD before the average age i.e. girls<8 and boys<9 years old
What are some common causes of precocious puberty?
Gonadotrophin secretinf tumours (trophin dependent)
Pineal tumours or meningitis (early stimulation of neurological maturation)
List some causes of gonadotrophin dependent precocious puberty
HInt: 3
Pineal tumours
CNS trauma (injury, surgery, infection)
Congenital disorders e.g. arachnooid cysts
Describe some causes of gonadotrophin independent precocious puberty
Hint: 2
Appearance of secondary sexual characteristics due to; increased production of sex hormones (i.e. gonad matures without GnRH stimulation)
LH&FSH suppression
Define delayed puberty
Initial physical changes of puberty not seen by 13 in girls and 14 in boys
When is pubertal development inappropriate?
When the interval between the first signs of puberty and menarche (in girls) or completion of genital growth (in boys) is >5 years
What 2 categories does delayed puberty fit into?
Gonadal failure - hypergonadotrophic hypogonadism
Gonadal deficiency
What are the causes of gonadal failure?
Turner’s syndrome
Post-malignancy chemo /radiotherapy /surgery
Polyglandular autoimmune syndrome
What are the causes of gonadal deficiency?
Congenital hypogonadotrophic hypogondaism
e.g. Adrenal hyperfunction or congenital adrenal hyperplasia
Hypothalamic/pituitary lesions
Gene mutations altering LH&FSH or their receptors (rare)
What is Turner’s syndrome?
Karyotype 45,X or 46,XX with structural abnormalities in X chromosome
What are the signs of Turner’s syndrome?
Hint: 5
Short Gonadal dysgenesis Skeletal abnormalities Cardiac and kidney malformation Dysmorphic face
How is Turner’s syndrome treated?
Hint: 2 methods
Growth hormone
Sex hormone substitution
What are the “Seven Dwarves” of the menopause?
Itchy, twitchy, sweaty, bloated, moody and forgetful
When is the pre-menopause?
~40yrs
What happens to the menstrual cycle in the pre-menopause?
The follicular phase shortens
What specifically can be absent during the pre-menopause and why?
Ovulation - less oestrogen and more FSH&LH
When does the menopause usually occur?
49-50
Define the menopause in terms of follicles
The time when there are none left to develop
What happens to oestrogen levels during the menopause?
Fall dramatically
What happens to FSH&LH levels during the menopause?
They both rise, FSH more so due to lack of inhibin
What vasuclar changes occur during the manopause and how can they be treated?
Hot flushes - treated with oestrogen
What other changes occur during the menopause?
Hint: 4
Regression of uterine endometrium and shrinkage of the myometrium
Thinning of cervix
Invlution of some breast tissue
Changes in bladder due to loss of pelvic tone (incontinence)
What happens to the bone during the menopause and how can it be limited?
Total mass reduced by 2.5% per year
Increased osteoclast activity as oestrogen drops leading to osteoporosis - oestrogen therapy
In contrast, what happens at the end of the reproductive life of the male?
No obvious event, sperm production continues into 60’s & 70’s, FSH&LH and oestrogen increase but testosterone levels decrease
What are the phases of the menstrual cycle?
Hint: 4
Proliferative
Secretory
Ischaemic
Mesntruation itself
What occurs during the proliferative phase?
Hint: 3 things
Menses
Folliculogenesis
Subsequent oestradiol production (responsible for proliferation of endometrium)
Which phase does ovulation occur directly after?
Proliferative
What levels of oestradiol are necessary for ovulation?
200pg/ml for approx. 50 hrs
What is needed to release the oocyte from the follicle?
Proteolytic enzymes and prostaglandins that digest the collagen in its wall
What do the granulosa cells do during the secretory phase?
Enlarge and accquire lutein, becoming the corpus luteum and secreting progesterone
What process occurs first if fertilisation doesn’t occur?
Luteolysis - the corpus luteum becomes the corpus albicans
During the ischaemic phase, which arteries are cut off from their blood supply?
The spiral arteries
How long does menstruation last?
24-32 days
How much blood is usually lost during menstruation?
37-43ml
What is menorrhagia and what are some common causes?
Heavy periods - Abnormal clotting Fibroids IUCD problems Cancer
What are the types of uterine fibroids?
Hint: 3
Subserosal
Submucosal
Intramural
What is DUB and what are the common causes?
Dysfunctional uterine bleeding - heavy bleeding due to;
Pregnancy
Idiopathic
Bleeding disorders
What commonly casues irregular bleeding?
Hormonal contraceptives
List some common types of amenorrhoea
Hint: 7
Prepubertal Pregnancy Menopause Uterine/Endometrial Ovarian Pituitary Hypothalamic
List some effects of menstrual disorders
Hint: 7
Tiredness Anaemia Depression Iritability Mood swings Anxiety Impact on ability to socialise
How are fibroids diagnosed?
Menorrhagia
Could be palpable
USS
What causes the hormonal changes in the hypothalamus and pituitary during the menopause?
Reduction in gonadal srteroid production
Whate are the main risks of HRT?
Thromboembolism
Breast cancer
