cartilage

cartilage , flexible semiopaque connective tissue without blood vessels or nerve cells. It forms part of the skeletal system in humans and in other vertebrates, and is also known as gristle. Temporary cartilage makes up the skeletal system of the fetus and the infant, forming a model for later replacement by bone as the body matures. Permanent cartilage remains throughout life, as in the external ear, nose, larynx, and windpipe (or trachea). Cartilage is also present at the joints , where it reduces friction and imparts flexibility. There are three major types of cartilage appearing in vertebrates. The most common is hyaline cartilage, which composes the pre-skeletal model and is found in adults at the joints, in the nose, and in several internal organs. Elastic cartilage is found in several parts of the ear and in the epiglottis, and is the most pliable type of cartilage. Fibrocartilage is found in the intervertebral disks, and is an extremely resilient tissue.

cartilage (kar-til-ij) n. a dense connective tissue, consisting chiefly of chondroitin sulphate, that is capable of withstanding considerable pressure. In the fetus and infant cartilage occurs in many parts of the body, but most of this cartilage disappears during development. Cartilage is the precursor of bone following a fracture (see callus). elastic c. cartilage occurring in the external ear. fibrocartilage cartilage occurring in the intervertebral discs and tendons. hyaline c. cartilage found in the costal cartilages, larynx, trachea, bronchi, nose, and covering the surface of the bones at joints.

cartilage Flexible supporting tissue made up of the tough protein collagen. In the vertebrate embryo, the greater part of the skeleton consists of cartilage, which is gradually replaced by bone during development. In humans, cartilage is also present in the larynx, nose and external ear.