2.3 Structure and strength: functions of bone and cartilage

Tissues such as bone and cartilage give our bodies structure and strength. The examples used are bone and cartilage.

There are many different types of cartilage, including articular cartilage, which covers the joints at the end of the bones. However, the example provided in the slide set that you will examine shortly is from the trachea (windpipe). This structure has bands of hyaline cartilage, which strengthen the trachea, to resist collapse or closure as the head moves.

Figure 9 (a) Diagram and (b) photograph of a partially sectioned long bone (femur), showing its internal structure. Erythrocytes and leukocytes are produced from stem cells located primarily in the red marrow. Yellow marrow produces factors (cytokines) that promote the development of the blood cells (Tortora and Grabowski, 1993).

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This shows a diagram and photograph of a partially sectioned long bone (femur), showing its internal structure.

Figure 9 (a) Diagram and (b) photograph of a partially sectioned long bone (femur), showing its internal structure. Erythrocytes and ...

Notice in these strong tissues how the cells form only a small proportion of the total tissue mass. They are responsible for forming, remodelling and repairing the tissue, but the strength is provided by the extracellular matrix (and mineralisation), including proteins such as collagen and elastin in tendons.

Mineralisation produces highly ordered structures around the cells, and is arranged to resist the stresses placed on the tissue. The hardest tissues of the body – bones and teeth – are mineralised with calcium hydroxyl apatite.