Index
It is a type of connective tissue found in areas such as the nose, ears, and windpipe of the human body.
The word hyaline means “glass-like,” and hyaline cartilage is a shiny, grayish-white tissue with a uniform appearance.
It is one of the three types of cartilage; the other two types are elastic cartilage and fibrocartilage . Hyaline cartilage is the most abundant type of cartilage in the body.
This type of cartilage has a glassy appearance when fresh, it looks slightly basophilic in the hematoxylin and eosin (H&E) sections .
Hyaline cartilage is somewhat flexible and elastic. It can withstand a considerable amount of compression and tension. The matrix contains collagen fibrils (not fibers), as well as glycosaminoglycans (GAGs). The fibrils are arranged according to the stress exerted on the cartilage.
Glycosaminoglycans trap large amounts of water, allowing the tissue to be avascular but have a high rate of diffusion. The hydrated matrix also acts as a shock absorber, an important characteristic for articular cartilage.
The cartilage is enclosed by the fibrous perichondrium, except on the articular surfaces (joints). Appositional growth occurs from chondroblasts that come from the perichondrium. The chondrocyte groups in the matrix are isogenic groups that represent interstitial growth.
Hyaline cartilage has widely dispersed fine collagen fibers (type II), which strengthen it. Collagen fibers are difficult to see in sections. It has a perichondrium, and it is the weakest of the three types of cartilage.
The three types of cartilage
There are three types of cartilage:
- Hyaline – the most common, found in the ribs, nose, larynx, and trachea. It is a precursor to bone.
- Fibro : found in invertebral discs, joint capsules, ligaments.
- Elastic – Found in the outer ear, epiglottis, and larynx .
Most of the skeleton is preformed in hyaline cartilage and, prior to maturation, the growth and development of many bones is largely determined by the hyaline cartilage content of the bones.
The following structures consist of hyaline cartilage throughout life:
- Articular cartilage, the smooth and wear-resistant articular surfaces of the synovial joints.
- The costal cartilages that connect the top 10 pairs of ribs to the sternum and provide the rib cage with flexibility and elasticity.
- Support rings within the elastic walls of the trachea and the larger bronchial tubes.
- Part of the support frame of the larynx (voice box).
- The flexible outer part of the nose that makes up most of the nostrils.
Hyaline cartilage function
Hyaline cartilage is rich in collagen, a protein found not only in connective tissue but also in skin and bones, and helps hold the body together. Hyaline cartilage provides support and flexibility to different parts of the body.
It is found in structures such as the nose, ears, and areas where the ends of the ribs meet the sternum, and in parts of the respiratory system such as the trachea and larynx, where it helps shape these parts but also gives them some flexibility. .
When hyaline cartilage is found on the articular surfaces of bones (the surfaces of the joints), it is called articular cartilage.
Articular cartilage works as a shock absorber and also reduces friction between the bones where they meet at the joints.
As a person ages, this cartilage can wear down, causing joint pain and inflammation that is sometimes only relieved by surgery.
Structure
As mentioned earlier, hyaline cartilage contains a large amount of collagen; it contains type II, specifically.
Type I is found in bones, organs, skin, and tendons, and most of the collagen in the human body is type I.
However, cartilage is made up of type II. Hyaline cartilage also contains the chondroitin sulfate molecule, which helps it resist compression. However, it is the weakest of the three types of cartilage because its collagen fibers are very fine.
Cartilage tissue does not have nerves or blood vessels. Instead, it has a simple structure that is primarily made up of groups of cells called chondrocytes embedded in an intracellular matrix.
The protoplasm (internal content of the cell) is clear and the cells have one or two nuclei. Chondrocytes are found in the lacunae, which are small cavities that surround the chondrocytes.
Hyaline cartilage, which includes the articular cartilage of the diarthrodial joints, consists of a single cellular component, the chondrocyte, which is embedded in a unique and complex matrix. A primary lagoon is a lagoon that contains a chondrocyte.
Adult articular chondrocytes are considered fully differentiated cells that maintain the constituents of the matrix in a state of low rotation equilibrium. Chondrocytes fulfill various functions during development and postnatal life.
In the embryo, the chondrocyte arises from mesenchymal progenitors from various sources, including the cranial neural crest of the neural ectoderm, cephalic mesoderm, sclerotome of the paraxial mesoderm, and somatopleura of the lateral plate mesoderm, depending on the final location of the cartilage.
The chondrocyte synthesizes templates, or cartilage anagen, through a process called chondrogenesis.
When that cell divides, the daughter cells form new boundary layers called secondary gaps, and the group of cells with gaps is called the cell nest.
Hyaline cartilage is very uniform in appearance. It is surrounded by a membrane called the perichondrium, which provides nutrients to the cartilage since cartilage tissue does not have its own blood vessels.
In microscope images, the collagen in the hyaline cartilage is not visible because it is so fine. The other types of cartilage, elastic and fibrocartilage, have collagen visible when viewed under a microscope.
Other types of cartilage
Elastic cartilage
Elastic cartilage, also called yellow cartilage, is found in the outer ear, the Eustachian (auditory) tube, and the epiglottis, which is the tissue that separates the trachea from the esophagus.
It is similar to hyaline cartilage and has yellow elastic fibers that make it very flexible. Its role is to shape and support these areas.
Fibrocartilage
Fibrocartilage is found in areas such as the symphysis pubis (where the pubic bones meet), the discs between the vertebrae of the spine, and the temporomandibular (jaw) joint. It contains cartilage tissue and white fibrous tissue.
Also, it is the only type of cartilage that has type I and type II collagen. It is flexible, resistant and elastic.
Related Biology Terms
- Cartilage – tough but flexible connective tissue found in places like the nose, ears, joints, and respiratory system.
- Collagen – a protein found in the skin and connective tissue; it is the most common protein in the human body.
- Fiber (anatomy) – An elongated filament found in connective tissue.
- Perichondrium – a layer of connective tissue that surrounds hyaline cartilage and elastic cartilage; It has functions in the growth, repair and supply of nutrients to the cartilage.
