Lecture 19 - Childhood Growth Flashcards
Why are childhood growth rates a good indicator of development?
Growth rates are well defined in healthy children so can be used of an indicator of good health.
What are the three main stages to human growth?
Infancy
Childhood
Puberty
What are the characteristics of the infancy compenent?
Rapid growth is for 2-3 years which is determined by nutrition.
What are the characteristics of the childhood components of growth?
Growth reliance switches from nutrition to reliance on hormones, mainly growth hormone and thyroid hormones.
Growth slows 2-3 years before puberty.
what are the characteristics of the puberty component of growth?
Growth spurt, increased height velocity due to sex hormones.
What causes the end of growth?
Fusion of the epiphyses of the long bones caused by oestrogen in boys and girls.
How is oestrogen generated in boys?
By conversion of testosterone by aromatase in the adipose tissue.
How does puberty vary in boys and girls?
It starts earlier in girls but lasts longer in boys.
What are some important determinants of childhood growth?
Parental phenotype and genotype Nutrition Quality and duration of pregnancy Psycho-social environment Specific system and organ integrity Growth promoting hormones and factors
How can a childs height be predicted?
Fathers height + mothers height +12.5cm/2
What is the difference between primary and secondary growth abnormalities?
Primary growth abnormalities are when the condition is intrinsic to the growth plate.
Secondary growth abnormalities are when the condition is a problem in the growth plate as a result of a condition.
What are the main causes of primary growth abnormalities?
Genetic abnormalities in the growth plate or abnormally formed bones.
Chromosomal abnormalities - Most common example is turners syndrome
What are some causes of secondary growth abnormalities?
All cause hormone problems that leads to poor growth: Malnutrition Intrauterine growth retardation Chronic disease Endocrine disorders
How is growth hormone secreted and how would you measure growth hormone in the body?
Growth hormone is secreted from the pituitary in a pulsatile fashion mainly at night. Would measure IGF-1 instead of GH as GH stimulates IGF1 production in the liver.
What are the effects of growth hormone?
It stimulates IGF-1 production (important for lots of growth key in lecture) in the liver and also has direct effects on the growth plate and cortical bone.
