1. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint® Lectures Lectures by April Lynch Restoring Aging Bones Current Issues in Biology, Volume 2 Scientific American

2. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones Osteoporosis, a condition marked by severe bone loss and debilitating fractures, is a major health problem facing older Americans. It is an especially serious challenge for post-menopausal women, half of whom will suffer an osteoporosis-related fracture.

3. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones Osteoporosis arises when the body’s natural cycle of bone dissolving and replacement gets out of balance, usually beginning around age 40. Thinning occurs when bone-removing cells, or osteoclasts, are more active than bone-building ones, or osteoblasts.

4. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones The result of osteoporosis is weakened bone, such as the damaged vertebrae shown here to the left of healthy ones. Diagnosis and treatment are improving. A newer imaging technique, called DEXA, can now spot weakened bone before fracture.

5. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones Newer or experimental drugs may further strengthen bone, primarily by blocking the activity of osteoclasts. But possible side effects require more study. Preventive measures adopted early in life, such exercise and regular calcium intake, also protect bone density. Recent bone-strengthening drugs have been found to reduce fracture risk by up to 50 percent over three years.

6. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones Preventive measures adopted early in life also protect bone density. You can build bone mass as a young adult and lower your risk of osteoporosis later by: Consuming recommended levels of calcium and Vitamin D throughout your life. Calcium builds bone, and Vitamin D boosts its absorption. Doing regular weight-bearing exercise, such as jogging, to build bone strength.

7. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones When not in balance, what natural process is thought to underlie osteoporosis? a) stress molding b) production of bone marrow c) bone formation d) fracture repair

8. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones When not in balance, what natural process is thought to underlie osteoporosis? c) bone formation

9. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones What two types of bone cells carry out bone dissolving and formation? a) osteoclasts and osteoblasts b) macrophages and astrocytes c) red blood cells and white blood cells d) red marrow cells and yellow marrow cells

10. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones What two types of bone cells carry out bone dissolving and formation? a) osteoclasts and osteoblasts

11. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones At about what age does bone thinning begin as dissolving begins to outpace bone formation? a) 60 b) 50 c) 40 d) 30

12. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones At about what age does bone thinning begin as dissolving begins to outpace bone formation? c) 40

13. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones On average, what percentage of post-menopausal women will suffer an osteoporosis-related fracture? a) 10% b) 25% c) 50% d) 90%

14. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Restoring Aging Bones On average, what percentage of post-menopausal women will suffer an osteoporosis-related fracture? c) 50%

15. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Biology and Society Restoring Aging Bones Preventive steps such as consuming enough calcium and getting regular exercise can reduce the risk of osteoporosis. I would rather follow these measures now than start drug therapy to strengthen my bones later in life. Strongly Agree Strongly Disagree A. E. C. B. D.

16. Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Thinking About Science Restoring Aging Bones Recent studies suggest that estrogen-based hormone replacement therapy, once thought to help prevent osteoporosis, may sometimes cause other diseases such as breast cancer. But some scientists have devised a synthetic hormone, estren, that might work instead. Given what you’ve learned about estren, what are some ways it could be tested for potential side effects?