Bones are alive.
Not something we really consciously think, given that we’re used to seeing dinosaur bones on display in museums. Or plastic skeletons at Halloween. Or bones left over from the roasted turkey at Thanksgiving. Bones separated from life.
But while we’re alive, bones are constantly being remodeled. Approximately 10% of our bone is replaced every single year.
Why? Because it’s a living tissue that’s responding to the forces placed upon it during daily life (e.g. walking, running, weight lifting) as well as the occasional traumatic event (a broken bone).
Strengthen this part, not so much another.
But how?
Through the efforts of two cell types: osteoblasts and osteoclasts.
Osteo—the Greek word root that means bone
Osteoblasts—cells that build bone
Osteoclasts—cells that break bone down
BUILD IT UP
Osteoblasts are cells that build bone by laying down bone matrix (also called osteoid), a matrix composed of proteins and other organic material. While at work, osteoblasts send out a signal that causes the local level of bone minerals to rise and deposit into this newly built matrix. This mineralizes and hardens the bone—a process know as ossification. The resulting bone mineral is called hydroxyapatite and is comprised of Calcium (Ca) phosphate (P)—Ca3(PO4)—crystals.
So bones are part organic (the bone matrix/osteoid) and they are part inorganic (hydroxyapatite).
Why both?
Because while hydroxyapatite crystals are really hard, they’re also inflexible and brittle. Which is a problem if you don’t want your bones breaking all the time.
On the other hand, the matrix, the osteoid, is super flexible and really good at resisting high tension (pulling forces).
The osteoid locks hydroxyapatite (bone mineral) inside its matrix, and together they form an extremely strong structure.
In fact, bone is on par with steel reinforced concrete. Except bone can repair itself.
BREAK IT DOWN
Now, we can’t just be building bone. Sometimes we need to do some structural remodeling. Bones grow. Bone break. Weights are lifted. Some people take up extreme sports.
For this we turn to the osteoclasts: cells that break bone down. They do this by dissolving bone and sending the minerals back into the bloodstream as calcium and phosphate.
And then, with those liberated bits and pieces, osteoblasts can build bone in a new location. This allows us to move bone to where it’s most needed according to demands.
BALANCE EVERYTHING
Healthy bone needs both osteoblasts and osteoclasts working in equilibrium. Not too much. Not too little.
This is known as homeostasis—everything kept in balance.
Break this balance, build too much bone or not enough (osteoporosis) and we enter into a disease state.
OR ELSE
Our hero’s sister has brittle bone disease—also known as osteogenesis imperfecta (OI), a genetically inherited disorder.
The osteoblasts of a person with OI produce a bone matrix that is shaped in a way that prevents calcium and phosphate from binding to it correctly. And when that happens? You guessed it! The resulting bone is soft and brittle which places someone with brittle bone disease at high risk for for broken bones.
ENTER FICTION
Because of a certain similarity to calcium, heavy metal ions can be incorporated into the matrix of your bone.
And how better to strengthen bones than to turn them into metal?
Instead of phosphate, the hero of our story is attempting to cure his sister by replacing phosphate with an element called antimony.
Take a look at the Periodic Table. Phosphorus (15) is in the same column as Arsenic (33) and Antimony (51).
The elemental abbreviation for Antimony is Sb.
Antimony is a metalloid. It’s lustrous and gray. Unfortunately, it’s also quite toxic.
Which brings us to the opening scene of THE SILVER SKULL…
