cartilage, hyaline, elastic, whitefibro- discussion, viva

Cartilage:

1. What is cartilage?
• Cartilage is the semirigid specialized connective tissue and is nonvascular/ avascular in nature
2. What are the functions of cartilage?
• It exhibits tensile strength
• Provides firm structural support for soft tissues
• Allows flexibility without distortion
• Resilient to compression
3. What are the components of cartilage?
• Cartilage consists of cells (chondroblasts, chondrocytes) and extracellular matrix
• Extracellular matrix- composed of connective tissue fibers and ground substance
• Connective tissue fibers- collagen fibers, elastic fibers
• Ground substance- is formed by sulfated glycosaminoglycans and hyaluronic acid
4. The cells in the cartilage are called as?
• Chondroblasts- immature cells present in the inner cellular layer of perichondrium and synthesizes the extracellular matrix
• Chondrocytes- mature cells present in the center of the cartilage in groups called cell nests

Hyaline cartilage:

1. What are the characteristic features of hyaline cartilage?
• It is surrounded by perichondrium
• Matrix is homogenous and glassy due to the same refractive index of ground substance and collagen fibers
• Cells in the center present in groups called isogenous cell groups
2. What are the parts of hyaline cartilage?
• Perichondrium, extracellular matrix, cells
3. Explain perichondrium/ What is perichondrium?
• Perichondrium is the dense irregular connective tissue with fibroblasts divided into outer fibrous layer and inner chondrogenic layer
4. What are the layers of perichondrium?
• Outer fibrous layer- formed by collagen fibers
• Inner chondrogenic layer- formed by cells which gives rise to chondroblasts
5. What are the components of matrix?
• Extracellular matrix- composed of connective tissue fibers and ground substance
• Connective tissue fibers- type II collagen fibers, elastic fibers
• Ground substance- is formed by sulfated glycosaminoglycans and hyaluronic acid
• Cells are embedded in the extracellular matrix
6. Why is the matrix homogenous?
• Matrix is homogenous due to same refractive index of ground substance and the collagen fibers
7. What is the matrix surrounding cell nest called as? Why is it stained darkly?
• The matrix surrounding the cells nest is called as territorial matrix. It stains darkly because of aggregation of sulfates around the group of cells
8. What is interterritorial matrix?
• It is the extracellular matrix present between the cell nests
9. What is cell nest/ isogenous group of cells?
• In the center of the cartilage the chondrocytes are present in groups ( 2-4 cells) arrested in the matrix to form cell nest
10. What are chondroblasts and chondrocytes?
• Chondroblasts- immature cells present in the inner cellular layer of perichondrium and synthesizes the extracellular matrix
• Chondrocytes- mature cells present in the center of the cartilage in groups called cell nests
11. Give examples for hyaline cartilage/ name the sites where it is present.
• All the long bones in the developing embryo
• Adult- articular ends of bones, ends of ribs, nose, larynx, trachea, bronchi
12. What are the differences between hyaline and elastic cartilage?
• Refer the table below
13. What are the differences between hyaline and whitefibro cartilage?
• Refer the table below

Elastic cartilage:

1. What are the characteristic features of elastic cartilage?
• Surrounded by perichondrium
• Elastic fibers embedded in the ground substance along with type II collagen fibers
• Single cells present deep to perichondrium, large chondrocytes present in the center
2. What are the parts of elastic cartilage?
• Perichondrium- outer fibrous layer, inner chondrogenic layer 
• Cartilage matrix- cells, extracellular matrix
• Cells- chondroblasts, chondrocytes
• Extracellular matrix- fibers, ground substance
3. Explain perichondrium/ What is perichondrium?
• Perichondrium is the dense irregular connective tissue with fibroblasts divided into outer fibrous layer and inner chondrogenic layer
4. What are the layers of perichondrium?
• Outer fibrous layer- formed by collagen fibers
• Inner chondrogenic layer- formed by cells which gives rise to chondroblasts
5. What are the components of matrix?
• Cells and extracellular matrix
6. What is extracellular matrix?
• Extracellular matrix- composed of connective tissue fibers and ground substance
• Connective tissue fibers- collagen fibers, elastic fibers
• Ground substance- is formed by water, sulfated glycosaminoglycans and hyaluronic acid
• Cells are embedded in the extracellular matrix
7. What are chondroblasts and chondrocytes?
• Chondroblasts- immature cells present in the inner cellular layer of perichondrium and synthesizes the extracellular matrix
• Chondrocytes- mature cells present in the center of the cartilage in groups called cell nests
8. Give examples for elastic cartilage/ name the sites where elastic cartilage is present.
• External ear, walls of auditory tube, epiglottis, larynx
9. What are the differences between elastic and hyaline cartilage?
• Refer the table below
10. What are the differences between elastic and whitefibro cartilage?
• Refer the table below

Whitefibro cartilage:

1. What are the characteristic features of whitefibro cartilage?
• It is devoid of perichondrium, instead replaced by connective tissue sheath
• Large amount of type I collagen fibers running in bundles
• Small amount of cartilage matrix
• Chondrocytes arranged in rows
2. What are the parts of whitefibro cartilage?
• Cells, fibers embedded in ground substance
3. Is perichondrium present in whitefibro cartilage?
• No
4. What is the covering of whitefibro cartilage?
• Connective tissue sheath
5. What are the components of matrix?
• Cells and extracellular matrix
6. What is extracellular matrix?
• Extracellular matrix- composed of connective tissue fibers and ground substance
• Connective tissue fibers- collagen fibers, elastic fibers
• Ground substance- is formed by water, sulfated glycosaminoglycans and hyaluronic acid
• Cells are embedded in the extracellular matrix
7. What are chondroblasts and chondrocytes?
• Chondroblasts- immature cells present in the inner cellular layer of perichondrium and synthesizes the extracellular matrix
• Chondrocytes- mature cells present in the center of the cartilage in groups called cell nests
8. Give examples for whitefibro cartilage/ name the sites where whitefibro cartilage is present.
• Intervertebral disc, pubic symphysis, articular disc
9. What are the differences between whitefibro and hyaline cartilage?
• Refer the table below
10. What are the differences between whitefibro and elastic cartilage?
• Refer the table below

Types	Hyaline	Elastic	Fibrous
Extracellular matrix	Homogenous, similar refractive index for the ground substance and collagen fibers.	Dense network of branched elastic fibers.	Alternating dense bundles of collagen fibers.
Ground substance	Mostly, type 2 collagen fibers embedded in glycosaminoglycans.	Elastic and collagen fibers embedded.	Type 1 collagen fibers embedded.
Cartilage cells (chondrocytes)	In lacunae, surrounded by territorial and interterritorial matrix. Center of cartilage, ovoid or spherical cells in groups or clusters (cell nests) and towards periphery, flat and single.	In lacunae, in the matrix. Superficial cells, small and elongated, while central cells large and rounded.	Chondrocytes in lacunae and fibroblasts in rows in the matrix.
Perichondrium Fibrous and chondrogenic layers	Present Absent over the articular cartilage.	Present	Absent
Examples	Nasal septum, Structural framework of larynx, trachea and bronchi, articular cartilage, costal cartilage, most of the fetal skeleton.	Auricle of external ear, auditory tube, parts of the epiglottis, cuneiform and corniculate cartilages of larynx.	Intervertebral disc, articular disc of the tempero-mandibular and sternoclavicular joints, pubis symphysis, grooves or insertions for tendons or ligaments, menisci of the knee joint.