multicentric

Your bones help you move, give you shape and support your body. They are living tissues that rebuild constantly throughout your life. During childhood and your teens, your body adds new bone faster than it removes old bone. After about age 20, you can lose bone faster than you make bone. To have strong bones when you are young, and to prevent bone loss when you are older, you need to get enough calcium, vitamin D, and exercise. You should also avoid smoking and drinking too much alcohol.

Bone diseases can make bones easy to break. Different kinds of bone problems include:

• Low bone density and osteoporosis, which make your bones weak and more likely to break
• Osteogenesis imperfecta makes your bones brittle
• Paget's disease of bone makes them weak
• Bones can also develop cancer and infections
• Other bone diseases, which are caused by poor nutrition, genetics, or problems with the rate of bone growth or rebuilding

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases

The lymphatic system is a network of tissues and organs. It is made up of:

• Lymph - a fluid that contains white blood cells that defend against germs
• Lymph vessels - vessels that carry lymph throughout your body. They are different from blood vessels.
• Lymph nodes - glands found throughout the lymph vessels. Along with your spleen, these nodes are where white blood cells fight infection.

Your bone marrow and thymus produce the cells in lymph. They are part of the system, too.

The lymphatic system clears away infection and keeps your body fluids in balance. If it's not working properly, fluid builds in your tissues and causes swelling, called lymphedema. Other lymphatic system problems can include infections, blockage, and cancer.