Tissue

A tissue is made up of a group of cells that usually look similar to one another and come from the same region in a developing embryo. The group of cells that make up a tissue have physiological functions that work together in a coordinated way to support special functions. The special function of a tissue is also influenced by the kind of material that surrounds the tissue and by communication among the cells of the tissue. Different kinds of tissue have different physical properties. Tissues may be hard (bone), soft (muscle), or even liquid (blood).

In the structural organization of the body, tissues are located between the cell and organ levels of organization. Individual cells are a lower level of organization. Tissues are made up of many individual cells. Groups of different kinds of tissues are organized together to form organs, which have special functions with characteristic shapes and functional properties.

There are four kinds of tissues based on differences in their anatomy and function: epithelial tissue, connective tissue, muscle tissue, and nervous tissue. Epithelial tissue is made of layers of cells that are joined together and may cover the surface of the body (epidermis of the skin), line spaces in the body (lining of the abdominal cavity) and hollow structures (lining of blood vessels), or form glands (sweat glands). Connective tissue is usually made of cells and extracellular fibers that hold structures together (tendons), protect them (cartilage), store energy (fat), or produce blood.

Muscular tissue is made of cells that are organized to shorten and produce force when they contract (smooth skeletal and cordine muscle). Nervous tissue is made of neurons and accessory cells. Neurons are the cells that carry information in the form of electric action potentials . Accessory cells protect and support the function of neurons.

see also Blood; Connective Tissue; Epithelium; Muscle; Nervous Systems; Neuron; Organ; Skin

Michael G. Scott

Bibliography

Tortora, Gerard J., and Sandra R. Grabowski. Principles of Anatomy and Physiology. New York: John Wiley & Sons, Inc., 2000.

tissue, in biology, aggregation of cells that are similar in form and function and the intercellular substances produced by them. The fundamental tissues in animals are epithelial, nerve, connective, and muscle tissue; blood and lymph are commonly classed separately as vascular tissue. In the higher plants, there are four main types of tissue: (1) meristematic tissue (apical meristem and cambium), composed of cells that grow, divide, and differentiate into all the other cell types; (2) protective tissue (epidermis and cork), composed of thick-walled cells that cover roots, stem, and leaves; (3) fundamental tissues, consisting of cells that make up the bulk of the plant body, including parenchyma (thin-walled cells used for food storage), collenchyma (moderately thick-walled cells used for strength), and sclerenchyma (heavily thick-walled cells used for support in stems and roots); and (4) vascular tissue (xylem and phloem), specialized cells used for conduction. Organs are usually composed of several tissues. In many diseases there are apparent changes in tissue (see pathology). Histology is the study of the structure of tissues.

tis·sue / ˈtishoō/ • n. 1. any of the distinct types of material of which animals or plants are made, consisting of specialized cells and their products: inflammation is a reaction of living tissue to infection or injury| (tissues) the organs and tissues of the body. 2. tissue paper. ∎  a disposable piece of absorbent paper, used esp. as a handkerchief or for cleaning the skin. ∎  rich or fine material of a delicate or gauzy texture: [as adj.] the blue and silver tissue sari. 3. [in sing.] an intricate structure or network made from a number of connected items: such scandalous stories are a tissue of lies. DERIVATIVES: tis·su·ey adj. (in sense 2).

tissue (singular): the term used to describe an aggregation of body cells with specialized structure and function (muscle, nerve, glandular, adipose, connective tissue and so on). Within each category there is usually more than one cell type — usually the main cells with a special function, plus connective tissue cells. Tissues (plural) refers in general to the whole fabric of the body — as in the statement ‘the blood transports oxygen and nutrients to all body tissues’, or sometimes ‘… to all organs and tissues’, using the word to cover everything which is not a discrete organ.

Stuart Judge

tissue (tis-yoo) n. a collection of cells specialized to perform a particular function. Aggregations of tissues constitute organs. t. culture the culture of living tissues, removed from the body, in a suitable medium supplied with nutrients and oxygen. t. typing determination of the HLA profiles of tissues (see HLA system) to assess their compatibility. It is the most important predictor of success or failure of a transplant operation.

tissue Material of a living body consisting of a group of similar and often interconnected cells, usually supporting a similar function. Tissues vary greatly in structure and complexity. In animals, they may be loosely classified according to function into epithelial, connective, skeletal, muscular, nervous, and glandular tissues.

tissue A collection of cells of similar structure organized to carry out one or more particular functions. For example, in animals nervous tissue is specialized to perceive and transmit stimuli. An organ, such as a lung or kidney, contains many different types of tissues.

tissue (arch.) rich cloth, esp. interwoven with gold or silver; †band of rich stuff XIV; woven fabric XVI; (fig.) fabric, network XVIII; animal or vegetable substance XIX. — OF. tissu, sb. use of pp. of tistre weave :- L. texere weave.

tissue A group of cells of similar types that work in a co-ordinated manner towards a common function. They are normally bound together by an intercellular substance. Some fluids (e.g. blood) are also considered to be tissues.

tissue A group of cells of similar type working in a co-ordinated manner towards a common function. In plants, they are normally bound together by their cell walls. Some fluids are also considered to be tissues.

Tissue

a web; a framework of something.

Examples : tissue of crimes, follies, and misfortunes, 1763; of epigrams, 1711; of lies; of misfortunes; of misrepresentations, 1820.

tissue •cachou, cashew •sandshoe • fichu •issue, Mogadishu, tissue •Honshu • horseshoe • snowshoe •Kyushu • gumshoe • overshoe