Growth Faltering Flashcards
what are the four drivers of normal growth
hormones
nutrition
genes
a good environment
what are the five different types of cell in the anterior pituitary
somatotrophs thyrotrophs gonadotrophs lactotrophs corticotrophs
what do somatotrophs secrete
GH
what does GH stimulate secretion of
insulin-like growth factors
what do thyrotrophs secrete
TSH
what do corticotrophs secrete
ACTH (and MSH)
what are the different actions of hGH between childhood and adulthood
in childhood:
increases the growth rate in skeleton nad skeletal muscles
in adulthood:
maintains muscle and bone mass and promotes healing
prepubertally what are the primary hormones for growth
Gh and TSH
what are the four phases of growth
foetal
infantile
childhood
pubertal
during which phase does most of the growing occur
childhood (40%)
during childhood when does most growth occur
at night as deep sleep promotes secretion of GH
in boys what causes fusion of the epiphyseal plates
testosterone is converted to oestrogen in some tissues causing fusion of hte plates
what is the most influential factor in the first two phases of growth
nutrition
how does PTH work in the bone
at physiological levels it stimulates OB to make bone
at increased levels OC is stimulated therefore slowing growth
how is asymmetrical growth restriction started
by comprimised nutritional delivery at a certain stage of pregnancy (usually last trimester)
what is asymmetric growth restriciton
a restriction of weight followed by lenght
head size is not usually affected
what is symmetrical growth restriction
the head is proportional to the rest of the body
the foetus is generally small indicating it has developed more slowly
give three causes of asymmetric growth restriction
chronic high blood pressure
severe malnutrition
genetic mutations (Ehlers-Danlos syndrome)
give four cuases of symmetric growth restriciton
early intrauterine infections (CMV, rubella, toxoplasmosis)
chormosomal abnormalities
anaemia
maternal substance misuse (alcohol)
what defines a baby as small for gestational age
if the birthweight and length are below the 3rd centile
impaired foetal and postnatal growth in term infants is related to a higher risk of what in later life
IHD
HTN
IGT and T2DM
increased risk of developmental and behavioural problems
how can growth hormone deficiency manifest
short stature and a tendency to be overweight
how can hypothyroidism affect growth
it results from a reduction of cartilage and bone formation resulting in short stature.
The child can also appear overweight
