This document discusses the structure and types of cartilage. Cartilage is a connective tissue composed of cells called chondrocytes within an extracellular matrix. The extracellular matrix contains ground substance and collagen or elastic fibers. There are three main types of cartilage - hyaline cartilage contains collagen type II fibers and is found in places like joints and trachea. Fibrocartilage contains collagen type I fibers and is found in intervertebral discs. Elastic cartilage contains elastic fibers and is found in the ear and epiglottis.

1. D R . A A M I R S H A H E E N
D P T ( A I M C ) , M . P H I L .
L E C T U R E R
Q U A I D - E - A Z A M E D U C A T I O N A L C O M P L E X ,
S A H I W A L
Cartilage

2. What is Cartilage
 Cartilage is a specialized variety of connective tissue,
which is strong but slightly flexible semirigid in
nature to bear considerable degree of mechanical
stress.
 Like any other connective tissue, cartilage is also
made up of cells and extra-cellular matrix.

3. Cartilage

4. Structure of cartilage
 Cartilage is made up of cells and extracellular material.
 Cells of cartilage are called as Chondrocytes.
 Chondrocytes are located within small cavities present in
the extra-cellular matrix. These cavities or small spaces
with matrix are called as Lacunae.
 Chondrocytes are large spherical cells with central
nucleus having one or two nucleoli.
 The cytoplasm is granular.
 Chondrocytes are the mature and isolated forms of
chondroblasts.
 Chondroblasts develop from mesenchymal cells.

5. Cartilage components

6. Continued…
 The extracellular matrix is secreted by chondrocytes
and has ground substance and connective tissue
fibers.
 The ground substance is made up of GAGs and
proteoglycans.
 Fibers are collagen or elastic types.

7. Some General Features of Cartilage
 It has high tensile strength and resistance to compressive
and shearing forces.
 It is an avascular tissue.
 Usually the cartilages are covered from outside by sheath
of dense irregular connective tissue, called as
perichondrium except articular cartilage.
 Perichondrium has two layers,
 Outer Fibrous layer having fibroblasts and collagen fibers with a
blood vessels, lymphatic vessels and nerves.
 Inner cellular layer containing chondrogenic cells, which is capable
to transform into chondroblasts.
 It doesn’t have any nerve supply or sensory receptors.
 Regeneration is not so much effective especially in
articular cartilage which lacks perichondrium

9. Types of Cartilages
 On the basis of types of fibers present in extracellular
matrix, cartilages are of three basic types,
1. Hyaline Cartilage
2. Fibro Cartilage
3. Elastic Cartilage

11. Hyaline Cartilage:
 The word Hyaline means glass like.
 This is a type of cartilage which is bluish white or
translucent in appearance just like frosted glass upon
seeing with naked eyes.
 This is the most abundant variety of cartilage.
 Extracellular matrix of hyaline cartilage predominantly
contains collagen type II fibers.
 Examples of Hyaline Cartilage:
 Embryonic cartilage
 Articular Cartilage
 Costal Cartilage
 Tracheal Cartilage
 Bronchial Cartilage

15. Fibro-Cartilage
 In this type of cartilage extracellular matrix contain
type I collagen fibers.
 Fibrocartilage is considered as combination of
hyaline cartilage and dense regular connective tissue.
 Chondrocytes are arranged in parallel rows.
 Fibrocartilage is not covered from outside by
Perichondrium.
 In appearance it looks white and opaque.
 It is less abundant.

18. Examples
 In human body fibrocartilage is located in the,
 Intervetebral Discs.
 Disc of Pubic Symphysis.
 Mensici of Knee joint.
 Intra-articular discs of TMJ and SC- joints.

19. Elastic Cartilage
 As indicated by name it is flexible, and capable to come
back to its original shaped after temporary deforming
force.
 Fresh elastic cartilage looks yellowish and opaque.
 Extracellular matrix contain collagen type II fibers and
Elastic fibers in abundance.
 Examples:
 In the human body elastic cartilage is located in
 Pinna of Ear (Auricle)
 Epiglottis of Larynx
 Audiotory Tube

22. Histology Diagrams of Cartilages for Practical
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23. Thank You