Chondrocytes

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Chondrocytes, as the name, suggests means cells that are related to cartilages. These chondrocytes are responsible for producing and maintaining cartilaginous cells and cartilaginous matrix inside our body. Here, we will learn what are chondrocytes, their structure, and their functions. Our body is able to perform many functions for the tissue system present in our body. The tissue system is composed of tissues and organs and these tissues are made up of cells. We all know that cells are the basic structural and functional unit of life. They perform almost all the important functions of our body. 

But, have you ever wondered where do these cells come from? Cells arise from pre-existing cells so there are different cells that are specialized in our body to form and maintain certain types of cells. 

What are Chondrocytes?

Here we will learn about chondrocytes meaning. Chondrocytes are the cells that are solely responsible for producing cartilaginous cells and matrix. Not just producing but they help in maintaining them too. An immature chondrocyte is known as a chondroblast. The cartilaginous matrix is comprised mainly of collagen and proteoglycan. Now here a question arises that where are chondrocytes found. The chondrocytes location is in the cartilage connective tissue. Apart from them, no other cells are located here. They are found in the cartilage matrix which is a kind of lake for them where they swim. 

Chondrocytes Structure

When observed through the microscope these chondrocytes are in the shape of a polygon or round shape. But when these chondrocytes are present in the tissue boundaries they can be in a discoid or flat shape. Intracellular spacing is present in synthetically active cells. The adult chondrocytes exhibit various amazing features. When they get flattened, they get themselves aligned parallelly to the collagen fibers in the superficial zones. When present in the intermediate zone, they appear more round and larger in size which helps them in exhibiting a bottom type of distribution where the fibers are oriented in a random pattern. Due to their position, these chondrocytes behave differently in different layers. When they are present in the inner zone they form columns and are aligned 90 degrees to the surface of the cartilage. For the spatial organization of the cells, the primary cilia are important. These primary cilia are also sensory organelles in chondrocytes.  

What is Perichondrium?

Perichondium is just a layer of dense irregular connective tissue. The cartilage of developing bone is surrounded by this perichondrium. It is made up of two separate layers which are the outer fibrous layer and the inner chondrogenic layer. Collagen fibers are produced by fibroblast cells which are present in the fibrous layer. The perichondrium is also found around the connective cartilage and hyaline cartilage. It contains type 1 and types 12 collagen which helps in the function and growth of cartilage. 

Chondrocytes Function

Here we will learn about the functions of chondrocytes and what do chondrocytes produce majorly. Chondrocytes are basically the metabolically active cells and they generally synthesize and turn a large volume of collagen, glycoproteins, proteoglycans. These are together known as the extracellular matrix. The functions of chondrocytes are listed below.

  1. They provide aid in joint articulation.

  2. They regulate the growth of epiphyseal plates. 

  3. They are present in cartilages in 1-7% amount which contributes to the low cell density of the cartilages. 

  4. They are major contributors to the extracellular matrix. 

  5. They provide the functional and mechanical ability to withstand compressional and tensile forces in the joints. 

Cartilage

It is a form of connective tissue and its cells are known as chondrocytes. It is avascular which means that gaseous metabolites and nutrients can diffuse through it to the cells. It is enclosed in the perichondrium. Perichondrium has the ability to secrete hyaline cartilage. These cartilages are present at the ends and between bones to protect them from injury and also to slow down the process of wear and tear of bones. They grow by the formation of an additional matrix and by the incorporation of new cells. In young human beings, they are present in more amount and as the child grows old these cartilages are converted to bones. This process is triggered by osteoblasts which help in the deposition of calcium in the cartilages and thus making them hard and stiff. Hyaline cartilage is the most distributed form of cartilage. It is found on surfaces of joints. 

Conclusion

From the above passage we can conclude that chondrocytes are the cells that are responsible for maintaining the cartilages and their matrix in our body. Cartilage is important for bones because it helps in providing cushioning to the bones and by sticking on their ends they protect the bones from wearing and tearing. 

FAQ (Frequently Asked Questions)

1. What are the three main types of Cartilages?

Answer: The three main types of cartilages are:

  • Fibro-Cartilage: Chondrocytes are present in very less amount, thus it is the least flexible cartilage. It is found in the parts of the vertebral disc and knees. 

  • Elastic-Cartilage: It contains the most number of chondrocytes, thus it is the most flexible. It is found in the parts of eustachian tubes(ear). 

  • Hyaline-Cartilage: It is the second most flexible cartilage. It is found in between the joints, nose, and end of the ribs. 

2. Where are Chondrocytes located?

Answer: They are located in intervertebral discs in the form of articular cartilage. They produce and maintain cartilage matrix. They help in maintaining homeostasis in the articular cartilage joints. They also help in repairing cartilages.