what factors influence growth
Hormonal, environmental, nutriotion, secular trends, genetics
what are the 4 hormones that affect growth hormonaly
- growth hormon
- somatostatin (GHIH)
- Growth hormone releasing hormone (GHRH)
- insuline-like growth factors (IGF-I and IGF-II)
what are the growth hormone effects at epiphyseal plates
- Stimulates protien synthesis hypertrophy of chodrocytes
- stimulates proliferation (hyperplasia) of chondrocytes
- increases calcium retention for enhanced mineralization
- stimulates osteoblastic cavity - bone density.
what is homeostatic regulation tightly maintained at
70 mg/dL and 110mg/dL
what happens if glucose rises above 70 -110
insulin is released, stimulating bodie to remove glucose from the blood.
what happens if blood glucose level drops below 70 mg/ dL
glocagon is released, stimulating the body to release more glucose into blood
what is the role for growth hormones
increase length of long bones, enhances mineralization, improves bone desnsity
What does the thyroxine hormone do
stimulates bone growth and promotes synthesis of bone matrix
what does sex hormones do?
promote osteoblastic activity and production of bone matrix: responsible for adolescent groth spurt; promote conversion of epiphyseal plate to epiphyseal line
What does thyroid hormone thyroxin do indepth
needed for synthesis of GH and permissive for its action
promotes osteoblostic activity and synthesis of bone matrix
hypo-versus hyper thyroidism and efecs on growth
What is calcium posphorus and magnesium important for
bone
what is iron aand iodine importand for
iron: hemoglobin
iodine: Thyroid
what is Vitamin A,C, and D important for
(Bones)
what does malnutrition cause
stunted growth in childhood
delayed onset of puberty
what does over nutrition cause
accelerated growth and earlier onset of puberty
why is calcium important
calcium compnent of calcium phosphare and calcium carbonate, needed to make hydroxyapatite crystals that give bone it’s hardness.
what is vitamin D needed for
necassasary for calcium to be absorbed by smalll intestine
how strongly is adult hight influenced by genetic backgrounf
70-90 %
What is the unique abouut the fetal phase of growth
it is the most rapid, depends on inter-uterine environment, blood flor, placenta function, maternal size and nutrition.
What is the unique abouut the infancy phase of growth
Rapid length increaase in the first year, then levels off
depends on genetics and nutrition.
What is the unique abouut the childhood phase of growth
From 3 - puberty
relativiley constang GH, and growth. Any abnormalities in gh-IGF1 axis usually diagnosed in this stage, thyroid also really important.
