A tissue contains cells of similar structure and functions, and also other substances, working together to carry out specific tasks.

組織就是由構造及功能相近的細胞，再加上其他物質組合而成，並共同執行特定的任務。

There are four main categories of tissue in the human body:

人體內的組織主要分為四大類：

Epithelial tissue is formed by special cells that cover the surface of the body. It also forms the internal surfaces of many organs and glands. It has the functions of protecting tissues, helping secretion, and disposing substances.

上皮組織由數層特殊的細胞組成，覆蓋著身體表面，並作為體內許多器官和分泌腺的內膜，有保護組織、協助分泌及排泄物質的功能。

Connective tissue can be found all over the body such as bones, cartilages, ligaments, blood, and fats. It holds the different parts of the body together, forming the human body structure, and transport substances to different parts of the body.

結締組織織遍佈於身體各處，如骨骼、軟骨、韌帶、血液、脂肪等，負責將身體各部分固定一起，形成人體的架構，並送物質到身體各部分。

Muscular tissue consists of fiber-shaped cells. It has the ability to contract, and is responsible for the movements of different body parts.

肌肉組織由纖維狀的細胞組成，有收縮的功能，並負責身體各部分的活動。

Nervous tissue consists of neurons, forming a network to transmit messages inside the body. It is responsible for carrying and controlling electrical signals between the brain and different body parts.

神經組織由個別的神經細胞組成，構成了體內傳遞訊息的網絡，負責傳送與控制腦部及身體各部位所發出的訊息。