How Do Our Bones Grow?

and bones. So how do we do it? How do we soft fleshy humans turn soft fleshy food into bones. Let's start off by zooming in all the way down to the cellular level. Your body builds bone tissue with the help of specialized cells called osteoblasts. Osteoblasts work together forming a tight fit layer over areas where bone needs to grow or be repaired. These cells secrete a particular combination of amino acids, primarily glycine and proline. These amino

acids are the building blocks of proteins. Not unlike voltron, they fold up with each other into something more than the sum of their parts, though in this case it's not a space bearing super robot, but strong triple helix threads of protein. Your cells get these amino acids from the foods that you eat. Meat, fish, dairy, and lagoons contain both glycine and proline, and you can also get

proline from stuff like gelatine and cabbage. Once you're osteoblasts secrete the immuno acids and they come together to form the protein threads. Enzymes give those threads a stabilizing polish. Vitamin C helps those enzymes work. Without it, the threads can't come together to form bone tissue correctly. That's what happens in scurvy, and it's one of the reasons why you should eat some fruit sometimes. Cantaloup, citrus, kiwi, mango,

and berries are all good sources. The thus stabilized threads are molecules of what's called collagen, which is the most abundant protein in the animal kingdom. Collagen molecules packed together into long, thin fibers called fibrals. In there many types fibrals create these scaffolding that bodily tissues are built upon, from your corneas to your blood vessels to your skin. They're sturdy and kind of flexible, like steel beams in architecture.

They're also relatively lightweight. Adult human bones are about ten collagen by mass, but if your bones were collagen fibrals alone, you'd beat sentient silly putty. So to add further support your osteoblasts, guide deposits of a strengthening layer of mineral crystals along the fibrils, like pouring concrete over steel beams. The mineral in question here is the compound calcium phosphate. Calcium and phosphate bond in your system after you consume

foods that contain them. For calcium, that's dairy and soy products, eggs, shrimp, and dark leafy greens. For phosphate, it's dairy, whole wheat, nuts, and legumes, and this, along with dairy's amino acid content, is why milk and fortified food adds talk about how these products help build strong bones, though of course all the other foods we've mentioned due to this mineral coating is just a few atoms thick, but it gives bones their stiff structure, and it accounts for about of adults

bone mass. Finally, the coated fibrils get gummed together with a sort of shock absorbing glue made up of spiraled collagen molecules that can uncoil when stress is applied, and then snap back into shape. This helps prevent fractures at a molecular level, like if you connected your steel reinforced concrete beams with springs. Your skeleton also contains small amounts of magnesium, sodium, and bicarbonate, plus a bunch of water like by mass. So how does your body get ahold

of all of these substances. Well, your digestive system is a fancy molecular blaster. When you eat, your teeth, gastro intestinal muscles and digestive juices break food down to the point that it's molecules already to be harvested. Your gut bacteria helped too. There are some molecules that are cells can't process by themselves. Our gut bacteria eat those molecules

and poop out compounds that are cells can process. The cells in the walls of your swall intestine pass everything that they can into your blood stream to be carried on to maker cells like your osteoblasts. Today's episode was written by me and produced by Tyler Clang. For more on this and lots of other reinforced topics, visit our home planet Paw Stuff Works dot com