What is Hyaline Cartilage?

Niki Foster
Niki Foster

Hyaline cartilage is a type of body tissue, also called gristle. It is shiny, slippery, firm, translucent, and bluish-gray in color. It is simple in structure, with no nerves or blood vessels. It has high elasticity and helps cushion and protect bones. The word hyaline comes from the Greek for glassy, and refers to the translucence of the tissue.

Hyaline cartilage connects the ribs to the sternum.
Hyaline cartilage connects the ribs to the sternum.

This cartilage is one of the three main types of cartilage in the body, the others being elastic cartilage and fibrocartilage. Cartilage in turn is a form of connective tissue, which also includes bone, blood, and fat. Cartilage is stronger and more rigid than muscle, but more flexible than bone.

Hyaline cartilage can be found in the trachea.
Hyaline cartilage can be found in the trachea.

Hyaline cartilage appears on the ends of bones where they form joints, between the ribs and the sternum or breastplate, in the trachea and bronchii of the lungs, and in the ear and the larynx or voice box. It is also the forerunner of skeletal bones in the fetus. Hyaline cartilage becomes bone in a process called endochondral ossification. In the ear, hyaline cartilage helps to absorb loud sounds.

Hyaline cartilage, like elastic cartilage, is usually lined with perichardium, a layer of irregular connective tissue that aids in the growth and repair of cartilage. All types of cartilage gain most of their physical properties from the extracellular matrix, the material surrounding the cells, than from the cells themselves. The matrix of this type of cartilage is rich in type II collagen and proteoglycans, which contribute to its elasticity.

Cartilage is characterized by lacunae, literally "windows," in the matrix, in which the tissue cells are located. Each lacuna may hold from one, two, four, or eight cells. The fibers of the extracellular matrix form concentric lines around the lacunae. The cells, called chrondrocytes, are responsible for producing the extracellular matrix.

Cartilage does not grow as fast or as easily as some other body tissues because it does not have a blood supply. In addition, the chrondrocytes are unable to move outside of the lacunae to reach damaged areas. Damaged hyaline cartilage is often replaced by scar tissue consisting of the tougher and less flexible fibrocartilage, which can impair joint performance.

Hyaline cartilage appears on the ends of bones where they form joints.
Hyaline cartilage appears on the ends of bones where they form joints.
Niki Foster
Niki Foster

In addition to her role as a wiseGEEK editor, Niki enjoys educating herself about interesting and unusual topics in order to get ideas for her own articles. She is a graduate of UCLA, where she majored in Linguistics and Anthropology.

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Discussion Comments

anon953127

How does the thickness of hyaline cartilage increase?

anon261359

Can hyaluronic acid be used instead of collagen for joint pain?

seekinfo2

@Vaclav - Studies show that supplements have very little effect. Glucosmaine may slow the progression of deterioration, but does not stop it, and when hyaline cartlidge is damaged, scar tissue forms.

Vaclav

My mother takes glucosamine daily. Is it possible that she could be rebuilding cartilage?

vogueknit17

The concept that human beings have "gristle", as well as other animals, is one of many reasons that I am a vegetarian. The same applies to the organs all mammals have, which when talking about animals turn into "organ meat". I would not want anyone eating my or my family's "organ meat", especially not before we're done using it, so I cannot justify doing so to another animal.

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