The natural biological order dictates the growth proportions of the human body from conception to adulthood. Fifty percent of the total length of the human embryo is the head while the legs and arms are only 25%.
Right after given birth, the infant’s head size shrinks to 25% and the limbs increase to 37%. This changing proportion of head and limbs to overall length will continue to persist through childhood until adulthood when the head goes down to 12% and the extremities at 50% of the body length.
Accompanying Growth in Bones
The proportion al growth of the human body is supported by the accompanying growth of bones. At the start, during early infancy, the cartilage is slowly infused with bone as the infant grows further along.
The cartilage formation of the infant then becomes the model, the mold, for the eventual skeletal bone. Bone-forming cells are deposited into the cartilage shaft that lay the foundation for strength and weight bearing structure.
Control of Hormones
The proportionate growth is most importantly influenced by growth hormones (GH). GH is released by the hypothalamus gland and it has been scientifically observed to peak right after sleeping and also at the moment right before waking.
The slow and insufficient supply of GH can lead to dwarfism or stunted growth. On the other side, hypersecretion of GH can lead to gigantism which would markedly alter the proportions of limbs and enlargement of facial features.