Students investigate and compare the weight-bearing capacity of solid and hollow cylinders, and use their findings to make inferences about bone structure. Lessons from the guide may be used with other grade levels as deemed appropriate. Bones are living tissues that contain blood vessels and nerve cells within a structure composed of collagen a flexible fibrous material and minerals mainly calcium and phosphate.
Without calcium in the form of calcium salts , bone would be flexible and soft, and without collagen fibers, bone would be brittle. The collagen fibers and calcium salts together make bone almost as strong as steel, but much lighter. Unlike steel, bone can repair itself when broken with the help of bone-forming cells osteoblasts and bone digesting cells osteoclasts. To provide support and still be easy to move, bones must be both strong and lightweight. These features are most important for the long bones in arms, legs and wings.
Each human long bone is composed of a shaft diaphysis with two flared ends epiphyses. The diaphysis resembles a hollow cylinder. It is made of hard compact bone that is resistant to bending.
The inner cavity of the diaphysis contains yellow marrow that stores fat. The epiphysis is a thin shell of compact bone filled with a lattice or sponge-like structure that is surrounded by red marrow which makes red blood cells. Obtain and cook enough chicken pieces to provide one or more different bones any size or shape to each group of students. You also may have students bring leftover cooked chicken bones from home.
OR use the long bones prepared for the activity, "The Skeleton. Compact bone is dense and forms the outer layer of all your bones. An adult skeleton is made up of bones, which come in several different shapes and sizes. The shape of a bone reflects its role within your body:. Home Explore the BBC. This page has been archived and is no longer updated. Find out more about page archiving. Prehistoric Life. Calcium is vital for healthy bones. Between the ages of 9 and 18, it is important to get 1, milligrams mg of calcium every day.
These are the years when your bones are growing rapidly and need a lot of calcium to achieve their peak mass. Food sources of calcium are preferred. You can get calcium from:. It helps your body to absorb calcium from the food you eat. You should get at least international units IU of vitamin D every day. Some brands of orange juice, yogurt, breakfast cereals, and other foods also have added vitamin D. Egg yolks and liver also have vitamin D, as do fatty fish, such as salmon, tuna, and mackerel.
Everyone needs physical activity. Since bones are living tissues just like your muscles, they respond to physical activity by growing stronger. This stimulates your bones to increase the production of new bone tissue. Get at least 60 minutes of physical activity each day, and be sure some of it is weight bearing. This will improve your overall health, help you maintain a healthy weight, as well as keep your bones strong.
If you have any concerns about your health, talk to your doctor or a physical therapist to find out what kinds of activities are right for you. Calcium KAL-see-uhm. A naturally occurring mineral that is needed for strong bones and teeth. Bones provide the structure for our bodies.
The adult human skeleton is made up of bones. These include the bones of the skull, spine vertebrae , ribs, arms and legs. Bones are made of connective tissue reinforced with calcium and specialised bone cells. Most bones also contain bone marrow, where blood cells are made.
Bones work with muscles and joints to hold our body together and support freedom of movement. This is called the musculoskeletal system. The skeleton supports and shapes the body and protects delicate internal organs such as the brain, heart and lungs. The body is constantly building up and breaking down bone tissue as required. Healthy bone needs a balanced diet, regular weight-bearing exercise and the right levels of various hormones. Bone marrow is where blood cells are made. The three different types of blood cell made by bone marrow include:.
Our body is constantly remodelling its skeleton by building up and breaking down bone tissue as required. As a result, each bone is rebuilt from scratch about every decade. The bone cells involved in this process include:.
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