Types of Cartilage: Characteristics and Location

We have cartilage in various parts of the body; in the nose, inside the ear, even in the bronchi. Keep reading and we’ll tell you more about these fabrics.

According to different characteristics – in relation to its composition – it is considered that there are three types of cartilage ; hyaline, elastic and fibrous. These have some aspects in common, such as the fact that they constitute a special form of connective tissue.

In addition, they are firm, flexible and distributed in various parts of the body; from the bones, passing through the nose, ears, trachea, among others. Its functions are varied; For example, in the joints they help prevent friction between bone pieces and resist impacts. Do you want to know more about it?

What are cartilage?
In the body there are different types of tissues. One of these is the so-called “connective tissue”, which fulfills relevant functions such as providing structure, support and protection to other tissues and organs; in addition to storing and helping in the transport of various substances.

In turn, within the connectives are blood, lymph, adipose tissue, cartilage and bones. The last two make up the osteoarticular system; and although they are related and have similar functions, they also differ in several of them.

It is interesting to note that, in the fetus, most large bones are first formed as cartilage . They are then replaced, through a process known as endochondral ossification .

Cartilage is often found in the joints, although not exclusively, as it is also found in the ears, nose, trachea and other areas of the body.

This specialized connective tissue is made up of an extracellular matrix, for the most part (95%). It is made up of several types of collagen as well as hyaluronic acid. To a lesser extent, different cells are found, such as the following:

• Fibrocytes.
• Fibroblasts.
• Chondroblasts.
• Chondrocytes.

The latter have the function of carrying out the synthesis of collagen fibers. Finally, there are proteoglycans , molecules of the extracellular matrix that contain proteins and polysaccharides, and are responsible for the compressibility of cartilage .

Characteristics of cartilage tissue

Cartilage has some characteristics that allow it to differentiate itself from other connective tissues. Among these the following stand out:

• Within it, there are spaces called chondroblasts or lacunae , where chondrocytes are located.
• Chondrocytes are mature cells and chondroblasts are immature.
• Cartilage does not have nerve endings or blood vessels .
• Due to the above, they usually do not have color or sensitivity.
• Its cells are nourished through a process of passive diffusion, through the matrix.

Cartilage functions

First of all, cartilage is located on the articular surfaces of the bones and, between them, that is, in the joints. In this way, it allows mobility, while acting as a shock absorber to resist the forces exerted on the body.

Based on this, synovial fluid is deposited on the cartilage , which acts as a lubricant to reduce  friction in the joints that allow movement.

On the other hand, it can be between two bones, without it being a joint itself. For example, in the sternum and ribs. In this case, it acts more as a means of fixation.

Finally, we have cartilages such as those of the ears and the nasal septum, which serve to give shape to these structures; as well as that of the trachea, which constitutes its reinforcement.

Different types of cartilage

According to its characteristics and functions , we have different types of cartilage; hyaline, elastic and fibrous. Let’s look at each of them in more detail.

1. Hyaline

The hyaline is considered the most abundant in the body. This type of cartilage is present in the articular ends of the largest bones and ribs , as well as in the nose, trachea, larynx and even the bronchi.

It consists of few fibers and is covered by a sheath of connective tissue; the perichondrium. However, there is no perichondrium in the epiphysis or head of the long bones.

Your chondrocytes are organized in groups, called “isogenic” or “isogenic” groups. Since they lack blood supply, they are nourished through synovial fluid.

Hyaline cartilage contains several types of collagen, although type II predominates in its matrix. It also has proteoglycans and other non-collagenous proteins. Its appearance is whitish, with pigmented areas around the lacunae, in which proteoglycans predominate.

2. Elastic

As its name implies, it is characterized by its flexibility. This is due to elastin and certain fibers , as well as braided sheets of elastic material. Likewise, it has type II collagen.

It is found in various parts of the body, such as the following:

• Epiglottis.
• Larynx (cuneiform cartilage).
• Eustachian tube.
• Auricular pavilion.
• Walls of the ear canal.

Like the type of cartilage described above, it lacks irrigation and also has a covering (perichondrium). However, unlike that, in the elastic there are a greater number of isogenic groups and its color is moderately yellowish.

3. Fibrous

The fibrous is also called “fibrocartilage.” Contains type I collagen. It is generally avascular. However, in some cartilages of this type there is a blood supply.

Its chondrocytes are organized forming parallel rows between the collagen bundles. And the fibers in the matrix are denser, so it can withstand higher tensile forces .

Because of this, it works as a cushioning and resistance device against compression. Thus, it moderates stretching and helps avoid possible tears.

Structurally, it is a combination of the other two types . However, fibrous cartilage lacks a perichondrium. It is present in different parts of the body, such as:

• Insertion of tendons into bones.
• Knee menisci.
• Vertebral discs.
• Sternoclavicular and temporomandibular joints.
• Triangular fibrocartilaginous complex of the wrist.

Cartilage conditions and diseases

Different types of cartilage can be affected by injuries or various diseases that cause pain and inflammation, as well as deformity and mobility limitations.

In sports and physical activity in general (including dance), injuries in which ligament tears and other joint damage can occur are not uncommon.

Likewise, there are diseases such as osteoarthritis, in which a degeneration of the flexible tissue of the joint occurs , to the point that it can cause friction between the bones.

These damages are usually a consequence of age-related degeneration. However, cases such as arthritis can be caused by an immune system reaction in which the body attacks its own tissues.

Cartilage health

It is possible to prevent some cartilage conditions, although not in all cases. Avoiding sudden and repetitive movements is one of the most important measures, especially when doing exercises or sports.

On the other hand, there are foods that help take care of these structures, such as those that are abundant in vitamin C, collagen and omega 3. Some examples are eggs, fish, dairy products and nuts.

Ultimately, precautions must be taken regarding certain risk factors, such as excessive physical activity, obesity, stress or poor diet. These not only compromise the health of the cartilage, but also the health of the joints in general.