ANATOMY&PHYSIOLOGY FOR NURSES

FIBROUS tissue is often spoken of as a white fibrous tissue because it is composed mainly of white collagen fibres arranged in definite it is composed mainly of white collagen fibres arranged in definite lines. This arrangement gives great strength and fibrous tissue is found where resistance is required.  Between the definite bundles of white fibres some areolar tissue lies, which contains the nerves, lymphatics, and blood vessels supplying the structure. Fibrous tissue tough and strong. It forms ligaments, except the elastic ones, and tendons. The dura mater lining the skull and neural canal, the periosteum covering bone, the strongest layers of fascia separating muscular sheaths, the fibrous  layer of the pericardium, and the sclerotic coat of the eye, are examples of fibrous tissue. Cartilage or gristle is a dense, clear blue-white substance, very firm but less firm than bone, It is found principally at joints and between bones, The bones of the embryo are first cartilage, then the growing centres persist as cartilage and when adult age is reached cartilage is found covering the bone ends. Cartilage does not contain blood vessels but is covered by a membrane, the perichondrium, from which it derives its blood supply.There are three main varieties of cartilage which demonstrate the characteristics of this substance- firmness, flexibility and rigidity. Hyaline cartilage consists of collagen fibresembedded in a clear, glassy, tough ground substance or matrix. The collagen fibres can only be identified if the matrix is dissolved away. It is firm and elastic and is found covering the ends of the long bones as articular cartilage, in the costlal cartilages, in the nose, larynx, trachea, and bronchial tubes where it keeps open the orifices. It is also the temporary cartilage from which bone is formed. In the developing embryo and foetus it acts as a temporary scaffolding supporting the other tissues until bone is laid down to replace it. The cells of hyaline cartilage are arranged principally in small groups in a tough matrix.

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