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?
If there are 100 people measured, how many people will be within 2SD of the mean value?
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?
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?
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?
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?
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?
In girls, FSH induces the proliferation of which 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