Growth, Puberty and Adolescence Flashcards
What is standard deviation?
It is a measure of variability- the wider it is, the more variation
What is the z-score?
The number of standard deviations away from the mean
If there are 100 people measured, how many people will be within 1SD of the mean value?
68
If there are 100 people measured, how many people will be within 2SD of the mean value?
95
On a growth chart, how far apart are the centile lines spaced?
2/3rds of a standard deviation
At what age in childhood will a child be leanest?
3/4/5
How much do babies roughly grow per year? What is this driven by?
20cm a year, driven by nutrition
What drives the teenage stage of growth?
Hormones
How should babies be weighed?
With no clothes or nappies
What should children ages older the 2 be wearing when getting weighed?
Vest and pants (no shoes, or toys in hand)
What scales should be used to measure weight?
Class III electronic scales in the metric setting
When should a babies length be measured? How many people are required to do this?
If they are < 2 years and you are concerned about their growth. Needs two people.
What should a baby be wearing to get their length measured?
Nothing (not even nappy)
Where should head circumference be measured?
Where the head is widest
When should a child’s height be measured?
From 2 years of age
How should the child be standing to get their height measured?
Heels, bottom, back and head touching the apparatus, with eyes and ears at 90 degrees
Should you measure height on inspiration or expiration?
Expiration
When is a child described as being ‘on the X centile’?
If they are exactly on the centile line or within 1/4 space of a centile line
When is a child described as being between centiles?
If they are outwith 1/4 of a centile gap
When does puberty occur?
When the secretion of gonadotrophins by the hypothalamus increases
What other hormone is produced once GnRH is stimulated to be released from the hypothalamus at the start of puberty?
Pulsatile secretion of LH increases which results in secondary sexual development
In boys, LH stimulates where to do what?
Leydig cells to produce testosterone
In boys, FSH stimulates where to do what?
Sertoli cells to enhance spermatogenesis
What hormone rises when sex hormone binding globulin levels fall in boys?
Androgens
In girls, LH stimulates the production of which cells?
Follicular and theca cells
In girls, LH stimulates the secretion of which hormone during the follicular stage of the menstrual cycle?
Androgens
In girls, FSH induces the proliferation of which cells?
Granulosa cells
In girls, FSH increases the activity of what? What is the function of this?
Aromatase; so that more androgens are converted to oestrogens
Ovulation results from the interaction of which hormones on the developing follicle?
LH, FSH and oestrogen
In both sexes, during puberty there are increased levels of sex hormones and insulin. What effect does this have on GH and IGF-1?
Secretion is enhanced
What are the relative LH and FSH levels when a child is first born? What happens after this?
They are high at birth and then stop in the first year of life until puberty
What is the average age of puberty for girls and boys?
Girls = 11, boys = 11.5
What is the relative weight of girls with precocious puberty? Why?
They tend to be fatter because of increased leptin
What does stage 1 of the tanner scale show?
Pre-pubertal body
What does stage 5 of the tanner scale show?
Adult body
What is the best measurement of the onset of puberty in boys?
Testicular volume
What indicates the beginning of puberty in boys?
Testicular volume > 4ml
What is the best measurement of the beginning of puberty in girls?
Breast development
What is thelarche?
Breast development
What is adrenarche?
Body hair and odour development
What is menarche?
Start of periods
What is the timescale of menarche in relation to thelarche?
Menarche is usually 2 years later
What is true central precocious puberty?
Normal pubertal development occurring abnormally early
What is precocious puberty for girls?
< 8
What is precocious puberty for boys?
< 9
Which sex does precocious puberty occur more frequently in?
Females
What is pubertal delay?
The absence of secondary sexual development (girls - breasts, boys - testicular volume < 4)
What age is pubertal delay in boys?
14
What age is pubertal delay in girls?
13
Pubertal delay occurs more commonly in which sex?
Males
When do girls reach peak height velocity?
12 years
When do boys reach peak height velocity/
14 years
Why do boys end up taller than girls?
Their growth plates form around 3 years alter so they have a higher pre-pubertal height
What hormones should be tested when assessing a growth problem?
Gonadotrophins, growth hormone and factors, testosterone/oestrogen, thyroid
How do you assess bone age?
X-ray of the non-dominant wrist
Why should you only perform a growth hormone stimulation test if there is very high clinical suspicion?
Makes the child hypoglycaemic
What are some imaging tests which may be required in investigation of a growth problem?
USS uterus/MRI brain
Describe genetic short stature?
A healthy child who has inherited short stature from parents with no underlying endocrine abnormality and normal bone age
Describe constitutional short stature?
Late maturation causing short stature with unknown cause
When does constitutional short stature tend to present? What with?
Around puberty, with delayed onset and delayed bone age
What does the line down the middle represent?
The mean
What does this growth chart show?
Normal growth
What does this growth chart show?
What does this indicate?
Is this worrying?
Dropping centiles for weight
This indicates that the child hasn’t grown as much as they should have
Yes
This is a graph of weight distribution over the last 30 years showing a shift to the right.
What does the shift to the right indicate?
What does the longer tail increase?
What is the trend with height?
The mean value for weight has increased
Higher incidence of severe obesity
Upward, increasing height
