What is one of the hardest materials in the body?

Bone

Bone resist what 2 forces?

1. Tension forces

2. Shear forces

How would an engineer explain why bone is so strong?

Many bones are cyclindrical, and a cylinder is one of the strongest structures for its mass.

How is bone made hard?

Deposition of inorganic calcium salts

Where are inorganic calcium salts deposited?

In the ground substance

The flexibility of bone comes from what?

Organic elements of the matrix such as collagen fibers

What is the effect of heat on bone?

Heat removes the organic part.

What is the effect of acid on bone?

Dissolves out the minerals.

When treated with heat and acid, do bones still retain the shape of untreated specimens?

Yes, but the acid-treated bone becomes more fibrous.

After gently applying pressure to the heated bone & the acid-treated bone, what happens?

Heated bone becomes brittle and responds to pressure by breaking. The bone treated with acid bends.

What does the acid appear to remove from the bone?

Soaking a bone in acid will cause it to lose calcium carbonate, making it very flexible.

What does baking & soaking in acid appear to do to the bone?

Baking the bone seems to remove all organic material, making the bone hard and stiff. Soaking the bone in acids seems to remove all inorganic material, making the bone very flexible.

Which of the bones (acidified or heated) specimens would more closely resemble the bones of a child with rickets?

The bone treated with acid.