 formed in the brain coming through the tunnels in the skull to the outside world, so to speak. How did it get so thick, Doc? Well, when you have osteoporosis, the bone is being replaced with connective tissue, scar tissue, cartilage, and all that kind of stuff. And your body's trying to maintain the strength of the bony tissue, okay? But there's not enough bone to replace, not enough minerals to replace it, so it goes with the cartilage and connective tissue.