Human Anatomy - Cartilage Cells (For Medical and Allied Health care students...)

PhysioPulse

10 Dec 202204:27

Summary

TLDRDr. Abdul's video delves into the fascinating world of cartilage cells, explaining their role in human anatomy. Cartilage, a flexible and resilient tissue, is composed of chondroblasts, chondrocytes, and progenitor cells. These cells are crucial in the formation and maintenance of the extracellular matrix, which includes collagen and proteoglycans. The video also touches on cartilage nourishment, growth through interstitial and appositional means, and its slow repair process due to its avascular nature. Viewers are encouraged to follow Dr. Abdul on social media for more insights.

Takeaways

🦴 **Cartilage Structure**: Cartilage is a strong, flexible, and semi-rigid tissue that can withstand compression forces and bend.
🌟 **Composition**: It consists of 10% cells, 75% water, and other constituents like collagen fibers.
🔬 **Cell Types**: There are three types of cells in cartilage: chondroprogenitor cells, chondroblasts, and chondrocytes.
🌱 **Chondrogenesis**: This is the process of cartilage formation from condensed mesenchymal cells expressing collagen.
🔄 **Cell Differentiation**: Chondroblasts differentiate from mesenchymal stem cells and secrete the extracellular matrix of cartilage.
🧬 **Chondrocytes' Role**: Chondrocytes are responsible for producing the extracellular matrix rich in proteoglycans and elastin fibers.
🍃 **Nutrition**: Unlike other connective tissues, cartilage is avascular and relies on diffusion from nearby capillaries for nourishment.
📈 **Growth Types**: Cartilage growth occurs through interstitial (within the existing cartilage) and appositional (adding new layers) growth.
🏥 **Clinical Significance**: Cartilage has a slow cell division rate and is difficult to repair due to its avascular nature.
🔧 **Biomechanical Properties**: Cartilage growth is often measured by its biomechanical properties rather than size or mass.

Q & A

What are cartilage cells?
-Cartilage cells are specialized cells found in cartilage tissue, including chondroblasts, chondrocytes, and chondroprogenitor cells.
What is the composition of cartilage?
-Cartilage is composed of 10% cells, 75% water, and the remaining 15% is a mix of collagen fibers and other constituents.
How does cartilage withstand compression forces?
-Cartilage is a strong, flexible, and semi-rigid tissue that can bend and withstand compression forces due to its composition and structure.
What is chondrogenesis?
-Chondrogenesis is the process by which cartilage is formed from condensed mesenchymal cells that express collagen types 1, 3, and 5.
What is the role of chondroblasts in cartilage?
-Chondroblasts originate from mesenchymal stem cells and are responsible for secreting the extracellular matrix of cartilage.
How do chondroblasts mature into chondrocytes?
-As chondroblasts secrete the matrix and fibers, they become trapped inside it and mature into chondrocytes.
What is the primary function of chondrocytes?
-Chondrocytes are responsible for producing large quantities of collagenous extracellular matrix and ground substance rich in proteoglycans and elastin fibers.
How is cartilage nourished?
-Cartilage is nourished by long-range diffusion from nearby capillaries in the perichondrium, as it lacks its own blood supply.
What are the two types of cartilage growth?
-The two types of cartilage growth are interstitial growth, where chondrocytes grow and divide within the existing cartilage, and appositional growth, where new layers are added to the existing matrix.
Why is cartilage difficult to repair?
-Cartilage is difficult to repair because it is avascular and has a slow cell division rate, leading to slow turnover and limited self-repair capabilities.
How is cartilage growth quantified clinically?
-Cartilage growth is not usually quantified by an increase in size or mass but by its biomechanical properties, as it is avascular and has a slow turnover rate.

Outlines

00:00

🦴 Introduction to Cartilage Cells

Dr. Abdul, a physiotherapist, introduces the topic of cartilage cells in this video. Cartilage is a strong, flexible, and semi-rigid tissue that can withstand compression while also being able to bend. It is composed of cells (chondroblasts, chondrocytes) and an extracellular matrix that includes 10% aggregate, 75% water, collagen fibers, and other constituents. The video discusses three types of cartilage cells: control progenitor, remission camel cells, and cornrow blasts, detailing their roles in the formation and maintenance of cartilage. Chondroblasts are derived from mesenchymal stem cells and are responsible for secreting the matrix of cartilage. As they secrete and become trapped within the matrix, they mature into chondrocytes, which are large secretary cells that produce collagenous extracellular matrix and ground substance rich in proteoglycans and elastin fibers. The nourishment of cartilage is also explained, highlighting that it is avascular and relies on diffusion from nearby capillaries for nutrients and oxygen. The growth of cartilage is discussed in terms of interstitial and appositional growth, with the former occurring during childhood and adolescence and the latter involving the addition of new matrix layers by chondroblasts from the perichondrium. The video concludes with information on cartilage's slow cell division, slow turnover, and difficulty in repair due to its avascular and neural nature, and it is noted that cartilage growth is quantified by biomechanical properties rather than size or mass.

Mindmap

Keywords

💡Cartilage

Cartilage is a type of connective tissue that is strong, flexible, and semi-rigid, capable of withstanding compression forces while also being able to bend. It plays a crucial role in providing support and structure in various parts of the body such as the joints, ears, and nose. In the video, cartilage is described as being composed of cells and extracellular matrix, highlighting its importance in human anatomy.

💡Chondroblasts

Chondroblasts are cells that originate from mesenchymal stem cells and are responsible for secreting the extracellular matrix and fibers that make up cartilage. They are found in the outer layer of cartilage and mature into chondrocytes. The video explains that chondroblasts are actively involved in the growth and development of cartilage, particularly during childhood and adolescence.

💡Chondrocytes

Chondrocytes are mature cartilage cells that are responsible for producing large quantities of collagenous extracellular matrix and ground substance rich in proteoglycans and elastin fibers. They are large, secretary cells with a basophilic cytoplasm due to the presence of rough endoplasmic reticulum. The video emphasizes that chondrocytes are essential for the maintenance and repair of cartilage, although their division is a slow process.

💡Chordoprogenitor Cells

Chordoprogenitor cells are involved in the process of chondrogenesis, which is the formation of cartilage from condensed mesenchymal cells. These cells express specific collagen types and secrete molecules that contribute to the formation of the extracellular matrix. The video describes how these cells play a role in the early stages of cartilage development.

💡Extracellular Matrix

The extracellular matrix is a complex network of proteins and carbohydrates that provides structural and biochemical support to the cells within tissues. In cartilage, the extracellular matrix is composed of collagen fibers, water, and other constituents, and it is secreted by chondroblasts and maintained by chondrocytes. The video explains that the extracellular matrix is crucial for the function and integrity of cartilage.

💡Collagen

Collagen is a family of proteins that provide structural support in various connective tissues, including cartilage. The video mentions collagen types I, II, IX, and XI, which are particularly important in the formation and maintenance of the cartilage's extracellular matrix. Collagen fibers contribute to the strength and flexibility of cartilage.

💡Proteoglycans

Proteoglycans are complex molecules that consist of a protein core with attached glycosaminoglycan chains. They are a significant component of the cartilage's extracellular matrix and contribute to its resilience and ability to withstand compression. The video highlights the importance of proteoglycans in the composition of cartilage.

💡Interstitial Growth

Interstitial growth refers to the process by which cartilage grows from within, as chondrocytes grow and divide and lay down more matrix inside the existing cartilage. This type of growth mainly occurs during childhood and adolescence, as explained in the video, and is a critical aspect of cartilage development.

💡Appositional Growth

Appositional growth is the process where new surface layers of the matrix are added to the pre-existing matrix by new chondroblasts from the perichondrium. This type of growth is discussed in the video as a way that cartilage can expand its surface area, contributing to the overall growth and development of the tissue.

💡Vascular

The term 'vascular' refers to the presence of blood vessels. In the context of the video, cartilage is described as avascular, meaning it lacks its own blood supply. Instead, it relies on diffusion from nearby capillaries in the perichondrium for nourishment. This characteristic influences the growth and repair capabilities of cartilage, as highlighted in the video.

💡Biomechanical Properties

Biomechanical properties refer to the mechanical characteristics of a biological material, such as its strength, elasticity, and resistance to deformation. The video mentions that the growth of cartilage is not typically measured by an increase in size or mass but rather by its biomechanical properties, which are crucial for its function in supporting and protecting the body's structures.

Highlights

Cartilage is a strong, flexible, and semi-rigid tissue that can withstand compression forces.

Cartilage is composed of cells called chondroblasts, chondrocytes, and extracellular matrix.

Chondrogenesis is the process of cartilage formation from condensed mesenchymal cells.

Chondroblasts originate from mesenchymal stem cells and are responsible for secreting the cartilage matrix.

Chondrocytes are responsible for producing collagenous extracellular matrix rich in proteoglycans and elastin fibers.

Cartilage is avascular, receiving nourishment through diffusion from nearby capillaries in the perichondrium.

Cartilage growth occurs through interstitial and appositional growth mechanisms.

Interstitial growth involves chondrocytes growing and dividing within existing cartilage.

Appositional growth adds new surface layers of matrix to pre-existing cartilage by new chondroblasts.

Cartilage has a slow cell division process and a slow turnover, making it difficult to repair.

Cartilage growth is not usually quantified by size or mass but by its biomechanical properties.

Chondrocytes contain a lot of rough endoplasmic reticulum, giving them a basophilic cytoplasm.

Older chondrocytes may contain fat droplets.

The extracellular matrix of cartilage is composed of 10% aggregate, 75% water, and a mix of collagen fibers and other constituents.

Chondroblasts mature into chondrocytes after secreting the matrix and fibers.

Cartilage cannot become very thick due to limitations in nutrient and oxygen supply through diffusion.

In contrast to cartilage, bone has a very good blood supply.

For clinical purposes, cartilage growth is characterized by the development of immature cartilage into a more mature state.