Cartilage is a type of connective tissue found all throughout the body, providing support and structure to various parts of the body without being as hard, rigid or as inflexible as bone. Cartilage is responsible for the shape of the ears, nose, and the larynx, or voicebox and helps make up the ribs and spinal column. Cartilage is thick and rubbery feeling. To get an idea of the external feeling of cartilage, one can press on the very tip of their nose or feel the upper part of the ear.
Cartilage is composed of specialized cells called chondroblasts, along with collagenous fibers. Sometimes elastic fibers can be found within cartilage, depending on the type of cartilage. Chondroblasts are responsible for secreting the substances that make up the rubbery matrix of cartilage. The chondroblasts continually secrete these substances until they are completely surrounding in the matrix within spaces known as lacunae. Catilage typically does not contain blood vessels and because of this, cell generation and the repair of damaged cartilage is a very slow process. There are three types of cartilage; hyaline cartilage, elastic cartilage
Hylaine cartilage is the most abundant type of cartilage found within the body. Hyaline cartilage, when examined microscopically, takes on a clear, glassy appearance due to the near-invisible fineness of the collagen fibers contained within the cartilage. Hyaline cartilage lines the joints, protecting the bones in the joints from being too abrasive on one another.
Elastic cartilage is flexible due the the elastin fibers contained within the cartilage. Elastic cartilage is the type of cartilage found in the upper ear, nose and larynx. Elastic cartilage is also found in a structure known as the Eustachian tubes. Elastic cartilage is able to maintain the shape and openess of tubular structures, while maintaining flexibility.
Fibrocartilage is the strongest, most rigid type of cartilage. Fibrocartilage takes on a very coarse appearance, and the thick bundles of collagen fibers are easily visible upon examination. Fibrocartilage contains a much higher amount of collagen fibers than any other type of cartilage. Fibrocartilage makes up the intervertebral discs, found between the vertebral discs. Fibrocartilage connects the tendons and ligaments to the bones, and is commonly found in areas of the body that endure great amounts of stress. When hyaline cartilage is damaged, it is often replaced with fibrocartilage, which lacks the flexibility of hyaline cartilage.
Saladin, Kenneth S.. Anatomy & physiology: the unity of form and function. 5th ed. Dubuque: McGraw-Hill, 2010. Print.
What is Cartilage?