Bones are rigid organs that form part of the endoskeleton of vertebrates. They function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals. Because bones come in a variety of shapes and have a complex internal and external structure, they are lightweight, yet strong and hard, in addition to fulfilling their many other functions. One of the types of tissues that makes up bone is the mineralized osseous tissue, also called bone tissue, that gives it rigidity and honeycomb-like three-dimensional internal structure. Other types of tissue found in bones include marrow, endosteum and periosteum, nerves, blood vessels and cartilage. There are 206 bones in the adult body and about 300 bones in the infant body.

　　骨為堅硬的器官，為脊椎動物內骨骼的一部分。其任用為運動、支撐和保護機體內各器官，產生紅血球和白血球，儲存礦物質。骨形狀多樣，內外結構復雜，重量輕但堅固結實，功能眾多。構成骨組織之一的礦物化骨狀組織，即骨組織，它使骨具備了硬性和蜂窩樣三維結構。另外，骨中還有骨髓、骨內膜和骨外膜、神經、血管和軟骨等。成人身體共有206塊骨，嬰兒約300塊左右。

　　The osseous tissue is a relatively hard and lightweight composite material, formed mostly of calcium phosphate in the chemical arrangement termed calcium hydroxylapatite (this is the osseous tissue that gives bones their rigidity). It has relatively high compressive strength but poor tensile strength, meaning it resists pushing forces well, but not pulling forces. While bone is essentially brittle, it does have a significant degree of elasticity, contributed chiefly by collagen. All bones consist of living cells embedded in the mineralized organic matrix that makes up the osseous tissue.

　　骨組織是一相對堅硬、質輕的復合材料，主要由磷酸鈣組成，化學排列中稱為鈣羥磷灰石，該物質使骨變得堅硬。它有相對較高的壓縮力，但拉伸度較差，也就是說，它抗壓力好，抗拉力強度。骨本質上很脆，但也有一定的程度且很重要的彈性，這主要歸功于它的膠原質。所有骨都是由活的細胞組織，包容在礦物化有機質中，并構成骨。

　　Bones may be classified according to their shape. There are long bones, short bones, flat bones, irregular bones and pneumatic bones.

　　骨可根據形狀分類，有長骨、短骨、扁骨、不規(guī)則骨和含氣骨。

　　Bones have eight main functions:

　　骨有8大作用：

　　 Protection — Bones can serve to protect internal organs, such as the skull protecting the brain or the ribs protecting the heart and lungs.

　　保護－骨用于保護體內器官，如顱骨保護大腦，肋骨保護心和肺。

　　Shape — Bones provide a frame to keep the body supported.

　　賦形－骨提供一個框架使身體得到支撐。

　　Blood production — The marrow, located within the medullary cavity of long bones and the interstices of cancellous bone, produces blood cells in a process called haematopoiesis.

　　造血－骨髓位于長骨髓腔和松質骨間隙內，骨髓通過造血作用產生血細胞。

　　Mineral storage — Bones act as reserves of minerals important for the body, most notably calcium and phosphorus.

　　礦物儲存－骨擔當一些對身體很重要的礦物質的儲庫，最主要的有鈣和磷。

　　Movement — Bones, skeletal muscles, tendons, ligaments and joints function together to generate and transfer forces so that individual body parts or the whole body can be manipulated in three-dimensional space.

　　運動－骨、骨胳肌、腱、韌帶和關節(jié)一起做功，完成力的生成和轉移，從而使全身各部分得以在三維空間內進行操作。

　　Acid-base balance — Bone buffers the blood against excessive pH changes by absorbing or releasing alkaline salts.

　　酸堿平衡－骨通過堿鹽的吸收和釋放調節(jié)血液的pH變化。

　　Detoxification — Bone tissues can also store heavy metals and other foreign elements, removing them from the blood and reducing their effects on other tissues. These can later be gradually released for excretion.

　　解毒作用－骨組織還能夠存儲重金屬和其他多種外來物質，將他們從血液中稱除，減少其對其他組織的影響。儲存的這些物質將逐漸通過排泄從體內釋出。

　　Sound transduction — Bones are important in the mechanical aspect of hearing.

　　聲音轉導－骨在聽力的機械力學方面很重要。