Normal and Abnormal Growth Flashcards
what is the middle line on a growth curve?
median/mean/50th centile
what does the standard deviation measure?
measure of variability
what is a Z score?
number of standard deviations from the mean
= (x - mean)/SD
if 100 people are measured, how many are within 1 SD from the middle line?
68
if 100 people are measured, how many are within 2SD from the midline?
95
how can a growth chart be used to determine normal growth?
child should stay on the same centile line for both height and weight as they grow
how does growth rate change over time?
increased rate up until around 1
rate decreased until around 11-12 where it spikes
rate then decreases to zero by late adolescence
how does weight change over time?
born with lots of “puppy fat”
decreases until around 5 where child is at their thinnest
weight then rebounds and begins to increase again
if more overweight at 5 yrs when weight is at its lowest, weight rebounds faster and weight increase after 5 is more rapid
what defines normal growth in children?
their measurements are within normal range compared with children of same age
their rate of growth is within the normal range compared to children of their age
how has growth in children changed over past 30 years?
increase in height and weight
what determines growth in children?
80-90% genetics
10-20% environment
how should children’s weight be measured?
babies = no clothes or nappy children >2 = vest and pants, no shoes, dolls or teddies in hands only class III clinical electronic scales in metric setting used
how is head circumference measured?
at widest point
using narrow plastic disposable paper tape
how is length measured?
<2 years if concerned
length board/mat
without nappy or footwear
- can vary depending on mood of child etc
when/how should height be measured?
from 2 y/o
using rigid rule with T piece or stadiometer
measure on expiration with shoes removed
how is growth plotted on a chart?
use dot
age in weeks for first 6-12 months
how are centile lines used?
if the point is exactly on the line or within 1/4 of a space of the centile line the child is described as being on the centile line
if not they are describes as being between centile lines
a change in how many centile spaces is considered abnormal?
2
- centile space = space between 2 centile lines
- can cross a centile line
at what age does a female enter puberty?
11 (average)
- boys usually 6 months later
what are gonadotrophins?
FSH and LH
what is precocious puberty?
early onset of puberty
- <8 in girls
- <9 in boys
when is puberty delayed?
absence of secondary sexual development in
- girls = 13
- boys = 14
more common in boys
what is the average height difference between adult males and females?
- 5-14 cm
- boys have delayed PHV
- boys PHV > girls
- boys taller in pre-puberty
what causes onset of puberty?
hypothalamic stimulation of anterior pituitary to produce gonadotrophins is on during pregnancy for development of genital etc
switched off at birth
switched on again around 11 causing onset of puberty
being overweight can cause earlier onset
