Bones store calcium for use in the rest of the body. How is the homeostasis of calcium controlled? = hormones from the endocrine system Which cells are osteoporosis drugs intended to inhibit? = osteoclasts Increased levels of calcitonin hormone may cause what? = low calcium levels in the blood Which hormones act against one another with calcium levels? = parathyroid hormone and calcitonin

How does vitamin D help maintain bones? = It increases calcium absorption from the diet. Which of the following is not a result of rickets? = Bowed legs in adults Which of the following structures allow external mechanical information to be quickly transmitted? = Canaliculi