Question: why do we grow ?

Angela Stevenson answered on 21 Nov 2013:

Great question Nicole! Could you imagine if we remained baby sized forever? it would be a tough life! Karen did a great job at answering why we grow, but how do we manage to achieve this? The bodies of humans and other animals all grow in different ways. What’s really cool is that all those bits of the body grow at the right sort of speed so that we don’t end up with a gigantic pair of feet and a tiny little heads (that would look funny hey). Let’s look at our bones. Their growth decides how tall we end up and these grow in length but not much in width. How long? Well that depends a bit on your genes and a bit on things like how good your diet is. You need calcium and vitamins to get good bone growth. What about muscles? Muscles try to keep pace with your growing bones and their growth depends on how much exercise you do or how much you use the muscles. And the same rule applies to lots of other bits of the body like the liver, kidneys, and lungs. The brain, however, gets to grown-up size and then just stops growing. So basically, body growth isn’t that simple and we don’t understand a lot about it yet. But we know that it grows (that’s why we don’t all remain baby sized) and we know that it grows at different rates in different people (which is why there are some super-short and very, very tall people). Hope that helps!