Cartilage - Anatomy & Physiology
Structure and Function of Cartilage
The function of cartilage is to resist compression, provide resilience and support at sites where flexibility is desired.
Structure
Chondrocytes
Reside within lacunae within ECM and are responsible for synthesizing the matrix. The matrix consists of type II collagen, (except fibrocartilage) and proteoglycans with associated glycosaminoglycans. They are continually turned over and are the most vulnerable component of cartilage. Decreased proteoglycan, causes loss of lubrication which results in collagen disruption. This includes, frays, clefts, fibrillation, ulcers, exposure of bone, eburnation, +/- osteophytes and joint mice.
Cartilage is avascular, nutrients and waste move via diffusion. The perichondrium surrounding the cartilage is composed of two layers:
1. Fibrous- outer, dense irregular connective tissue.
2. Chondrogenic- inner, flattened cells that differentiate to chondrocytes.
Types of Cartilage
Hyaline Cartilage
Hyaline cartilage is the most abundant in the body and surrounded by perichondrium. It is normally blue-white, smooth with a moist surface and turns yellow and becomes thinner in old age. It is found in nose, trachea, bronchi, ventral ends of ribs and sternal attachment. It provides a resilient, frictionless surface that resists compressionat at sites of articulation. It is also found at epiphyseal growth plates.
Elastic Cartilage
Elastic cartilage has a yellow appearance and is found in auricular cartilage, larynx, eustachian tube, and epiglottis. It is surrounded by perichondrium and has resiliance with added flexibility.
Fibrocartilage
Fibrocartilage has more collagen (Type I) and less proteoglycans than hyaline. It resists high tensional strain and is often in transition with hyaline. It is found in intervertebral discs, tendon/ligament attachment to bone, joint menisci, and articular surface of some joints (such as the temporomandibular). It has NO perichondrium.
| Cartilage - Anatomy & Physiology Learning Resources | |
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 Test your knowledge using drag and drop boxes |
Cartilage Histology Dragster |
 Selection of relevant PowerPoint tutorials |
Interactive tutorial on bone and cartilage histology |