# Growth lecture 1

version from 2017-11-07 17:40

## Section 1

When was the scientific revolution 1540-1690 Copernicus to Newton
When was the enlightenment 1690 – 1815 Newton and the Royal Society of London (for Improving Natural Knowledge),and the French Academy of Sciences. Being able to MEASURE.
Who was Georges Louis LeClerc? Compete de BuffonFrench Naturalist said to be the father of natural science. published 'histoire naturelle' 'natural history' where he included the serial measurement of the growth of a boy 1759-1777. Issue with at the time was that France had 250,000 different measures of weight and length (1 pied = 324.8mm, 1 pounce = 27.1mm, 1 ligne = 2.26mm). it wasn't until 1800 that they had the metre and cms. Also different areas of regions would have different lengths of the measure (324.8 for a pied in one place and 347.0 in the next) China, different length of a foot depending on trade.
How did we use to measure size Width of a finger = digit, width of a hand from thumb to baby finger with hand stretched = span, length of a foot = foot, length of tip of fingers to elbow= cubic . width of closed hand = hand, from knuckle on thumb to top of finger = inch. length of arms stretched out from tip of finger to the other = fathom, nose to finger= yard
What was the procedure for verification of the foot as described in the 16th century by Jacob Koebel. GeometreiStand at the door of a church on a Sunday and bid 16 men to stop, tall ones and small ones, as they happen to pass out when the service is finished; then make them put their left feet one behind the other, and the length thus obtained shall be a right and lawful rood to measure and survey the land with, and the 16th part of it shall be the right and lawful foot
What features of the procedure for verification of the foot were demonstrators of statistics 16 men= sample size, tall ones and short ones= variation, as they happen to pass out=randomisation, left feet one behind the other = standardisation, 16th part of it= normal distribution, right and lawful foot= external validity.
History of the inch England 1066 the length of three dried barleycorns placed end-to-end. Scotland 12th Century the width of an average man's thumb at the base of the nail. Similar units of measurement existed in many areas of what is now modern Europe, with the word for inch in Portuguese, French, Italian, Spanish and numerous other languages being the same or very similar to the word for thumb. The English word inch derives from the Latin uncia, meaning one-twelfth part (an inch traditionally being 1/12 of a foot). 1930 British Standards Institution inch = 25.4mm, 1933 with the American Standards Association ; 1951 Canada, -1959 the United States and British Commonwealth countries signed a treaty agreeing to the standardised 25.4mm definition.
How do you work out velocity distance/time. 'Speed of growth'
What was De montbeillard's son 1759-1777Distance curve and velocity curve plotted to show growth of child.

## Section 2

Describe the variation in growth patterns. X axis= age, years. Y axis= Size attained in percent of total postnatal growthBrain and head, fastly increased until it levels of at 100% at age 10. Reproductive= slow at around 10% until around age 13 where increases until 100% at 20. General = slow increase until adolescence where i increases more steeply from around 13. Lymphoid, bell shaped curve, increases until age 12 at 190% then falls until age 20. GRAPH PAGE 25
Describe the variation in the tempo of growth (from national children's home study)Photos of 3 boys all the same age (14.75) and 3 girls all the same age (12.75), all matured at different rates or tempo, photos show some have sexually matured and shape changed, other still look young like children.
What is Growth- structure. Formation of new tissue.
What is Maturation- function. Metamorphosis of the biological and chemical nature of tissue.
How do we know that growth status is normal?By comparison to the rest of the population. But how do we account for differences due to SES, ethnicity, exposure to growth constraints, etc.?. By using REFERENCES and STANDARDS.
What are references :-cross-sectional data -representative sample -growth “as is” e.g. NCHS/WHO, UK90
What are standards - longitudinal data - selected sample - growth “as it ought to be” or “optimal” e.g. WHO 2006
CDC growth charts for boys and girls from birth to 36 months Prior to 1980 data used- due to obesity. Centre for disease control Atlanta Georgia, GRAPHS ON PAGE 34 look at them. Individual charts for boys and girls with age along x axis and stature AND weight on y-axis.
Using cross sectional data points to produce an average curve of growth for example; the growth pattern of white British and Pakistani males; weight, with the mean curves plotted, average weight at that gestational age pg 37
Using longitudinal data to produce an average curve of growth, shows that Children follow a predictable pattern of growth and development that varies in timing and magnitude but is constant in the achievement of developmental landmarks
Height distance standard shows the average height of children that age in percentiles, with the middle value being the 50th percentile, canalisation; growth begins and ends on the 50th centile.
what does Canalisation mean is a measure of the ability of a population to produce the same phenotype regardless of variability of its environment or genotype. It is a form of evolutionary robustness
What does the distance standard graph on page 43 show Girl shows canalisation. Earlier age of menarche at 12, therefore earlier adolescent growth spurt, (about year earlier at that time). only time she moved away from the 50th percentile.
look at graphspages 42,43,44

## Section 3

Example of cause for disordered growthgrowth hormone deficiency
What does growth hormone do breaks down fat to produce energy for growth, therefore those who are deficient are smaller and fatter .
Where did we use to get growth hormone from before we could make artificial versionfrom anterior pituitary gland, taken from human cadavers.
When it comes to growth hormone deficiency; height, the longer you leave diagnosis/treatments all effects the..the lower the chance of getting into the percentile height they would have been o if they didn't have growth hormone deficiency to begin with.
What happens when you give growth hormone to those deficient in itCatch up growth occurs- catch up to the normal growth pattern and percentile lines, then growth slows before they grow at normal growth rate/velocity. DOES NOT help the person exceed this, but brings them up to the around the height they would have been had they not been deficient in the hormone.
Describe the graph of Colin, boy aged 7 with growth hormone deficiency; height. PAGE 46At age 7, he had the stature of a 1 year old and the skeletal structure of 2.5 years. Stopped his treatment at around age 12 for 6 months, where he didn't grow at all, so then he continues treatment and continues growing at normal speed.
What is catch up growth moving back up to percentile lines.
what is growth faltering when you move away from percentile lines.
What is clinically significant catch up growthgrowth greater than 0.67 Z-scores- shifting from one percentile to the next. Also for it to be catch up growth- have to demonstrate that there was a constraining factor on growth.
Describe Waddington's Epigenetic landscape (=biological development)Demonstrates TARGET SEEKING GROWTH PATTERN that within us there is the target we are going to hit for our physical size. (foetus has model of what we are going to be like). Epigenetic landscape-1957- study of modification of genetic potential.
What is the critical periodPeriod where if you are exposed to factors that affect you during this time, they have a significant impact on your final size/shape. Hills in diagram represent decisions that have to be made.
Describe child growth in terms of the epigenetic landscape Children follow a predictable pattern of growth and development that varies in timing and magnitude but is constant in the achievement of developmental landmarks.
When can you say a child has reached adult stature Growing at less than 1cm per year (growth velocity) . All stop growing around mid 20s but this varies per person.
describe "growth faltering" growth in terms of epigenetic landscape In response to constraint or insult the organism demonstrates “growth faltering”
describe "catch up growth" in terms of epigenetic landscape In response to an alleviation of constraint or insult the organism demonstrates rapid acceleration or “catch-up growth”