Flashcards in Week 3.0 - Puberty and menopause Deck (53):
1
Define Puberache
-Development of axillary and pubic hair
2
Define menarche
-First menstrual period
3
Define adrenache
-onset of increased androgen secretion
4
What is puberty?
-Stage of human development when sexual maturation and growth are completed and results in the ability to reproduce
5
Who begins puberty first girls or boys?
-Girls
6
Define thelarche
-Development of breast
7
Describe the main features of puberty
-Accelerated somatic growth
-maturation of gonads and genitals
-Development of secondary sexual characteristics
-Menstruation and spermatogenesis begins (reproductive system inactive before this)
8
With what hormonal changes is the onset of puberty associated with?
-Gradual activation of GnRH causing steady rise in FSH and LH
-Increased secretion of oestrogens and androgens
-Extragonadal hormonal changes -> elevation of adrenal steroids and IGF-1
9
Which hormones is the growth spurt dependent upon?
-Growth Hormone
-Sex steroid hormones
10
What is the difference between the growth spurt in girls and boys?
-Earlier and shorter in girls
(men are larger because growth spurt longer and slightly faster)
11
What signifies the end of the growth spurt?
-Epiphyseal fusion
12
What causes the growth spurt to be shorter in girls?
-Oestrogen closes the epiphyseal plates earlier
13
What controls the rate of genital development in boys?
-Testosterone
14
When does puberty typically begin in girls?
-8-13 years (mean 11.5 years)
15
When does puberty typically begin in boys?
-10-14 years (mean 12.5 years)
16
What is the critical weight for menarche?
-47kg
17
What is the relationship between weight and menstruation?
-If weight falls below ~47kgs then reproductive cycle will cease
-Overweight tend to start period early
-Obesity can also interfere with normal menstruation
18
Name one environmental factor thought to influence puberty?
-Light/dark exposure ie day length
-Altitude
19
What happens to the LH pulses on lead upto puberty?
-Pulses are negligible and then increase in amplitude and frequency
20
What is the first phenotypic change in girls?
-Breast development
21
What is the first phenotypic change in boys?
-Testicular enlargement
22
What is the relationship between sleep and LH?
-LH secretion is associated with REM sleep and begins as nocturnal pulsatility which causes a noturnal increase in sex steroid secretion
23
What initiates gonadal development in puberty?
-high levels of FSH and LH secretion
24
What happens after the gonads have started to develop in males?
-Spermatogenesis and androgen secretion begins
-Androgens initiate growth of sex accessory structures (eg prostate) and secondary sex characteristics
25
The adrenal glands secrete androgens, why does this not initiate puberty?
-Level too low
26
What is the relationship between TSH and puberty?
-As puberty starts TSH secretion from pituitary increases leading to increased metabolic rate and promotes tissue growth
27
What effects do androgens have on growth?
-Cause retention of mineral to support bone and muscle growth
28
Which sex steroid do sertoli cells secrete?
-Oestrogen
29
Which secondary sex characteristics are driven by androgens in females?
-Pubic hair growth
-Bone growth
-Sebaceous gland secretion
30
Where are androgens released from in women?
-Adrenals
31
State the order of pubertal changes in girls
-Thelarche
-Pubuc hair growth
-Growth spurt
-Menarche
-Breast development and pubic hair development complete
32
State the order of pubertal changes in males
-Genital deveopment
-Pubic hair growth
-Spermatogenesis
-Growth spurt
-Genital development and pubic hair development complete
33
What is tanner staging? explain it
-A method of staging pubertal development
-Different in girls and boys
-Each individual change has 5 stages
eg girls: Breast 1-5, Pubic hair 1-5, Axillary hair 1-5, menarche
boys: Testicular vol >4ml, Penis enlargment 1-5, pubic hair 1-5, axillary hair 1-5, spermache
34
What initiates the 1st ovarian cycle?
-1st LH surge
35
Define precocious puberty
-Onset of puberty before the average age
-Before 8 in girls and 9 in boys
36
How common is precocious puberty?
-1/5000-10,000
(much more common in females)
37
What is the most common cause of precocious puberty?
-Idiopathic
38
Besides idiopathic, what are the two types of causes of precocious puberty?
-Gonadotrophin dependant
-Gonadotrophin independent
39
Give an example of gonadotrophin dependant cause of precocious puberty
-Tumour eg hcg secreting tumour
-Trauma
-Nutritional status ie obesity
40
Give an example of gonadotrophin independent cause of precocious puberty
-Choriocarcinoma of gonads/pineal gland
-Meningitis
-Congenital adrenal hyperplasia
41
What is precocious pseudopuberty?
-Development of secondary sex characteristics without activation of the reproductive system
-Caused by an alternative source of androgen or oestrogen, independent of FSH/LH/GnRH
42
What is testotoxicosis?
-Familial male precocious puberty
-Autosomal dominant condition where there is rapid skeletal growth, skeletal maturation and sexually aggressive behaviour in the first 2/3 years of life
43
Define delayed puberty
Either:
-Initial physical changes of puberty are not present by age 13 in girls (or primary amenorrhea by 15.5/16) or 14 in males
or
-Pubertal development is inappropriate ie interval between first signs of puberty and menarche.complete genital growth is >5years
44
What are the 2 major causes of delayed puberty?
-Gonadal failure (hypergonadotrophic hypogonadism)
-Gonadal deficiency
45
Give some causes of gonadal failure
-Turners syndrome
-Post-malignancy treatment
-polyglandular autoimmune syndrome
46
Give some causes of gonadal deficiency
-Congenital hypogonadotrophic hypogonadism
-Hypothalamic/pituitary lesions
-Rare genetic mutations inactivating LH/FSH receptors
47
Describe pre-menopause
-typically from age 40
-Follicular phase shortens
-Ovulation becomes early/absent as primary follicles begin to run out-> reduced fertility
-less oestrogen secreted
48
Describe menopause
-Cessation of menstrual cycle for at least 12months
-Average age 49-50
-No more follicles
-Oestrogen levels fall dramatically thus FSH/LH rise dramatically (no inhibin)
49
Describe the effects of the menopause on oestrogen sensitive tissues
-Thinning of cervix
-Regression of endometrium/myometrium of uterus
-Vaginal rugae lost reducing vaginal tone
-Involution of breast tissue
-Urinary incontinence
50
Describe the effects of the menopause on bone
-Bone mass reduces by 2.5%/year for several years
-Enhanced osteoclast ability to absorb bone and attentuated osteoblastic activity
-Osteoporosis
51
Describe the purpose of HRT
-Relieve symptoms of menopause and improve well-being
-Can limit osteoporosis
(-given orally or topically)
52
Why might precocious puberty be stimulated by meningitis?
-Increased pressure due to swollen meninges causing activation of HPG axis
53