CARTILAGE Flashcards
What are the 3 types of cartilage
Hyaline, elastic, fibro
What are the functions of cartilage
Development and growth of long bones, supporting soft tissues, providing a smooth, gliding surface at joints, giving flexibility
What are some of the features of cartilage
-is a form of connective tissue, made by extracellular fibres embedded in a matrix that contains cells in small cavities
-It is avascular
-it is nourished by diffusion through matrix from the capillaries of perichondrium
-it does not repair as readily as other tissues
What is perichondrium
Outer covering of hyaline cartilage and elastic cartilage, not found in fibrocartilage
What are the two layers of of perichondrium
Outer fibrous layer with fibroblasts, inner cellular layer with chondroblasts
Fxn of fibrous layer
Produce collagenous fibres (type 1 + few elastics) for protection with blood vessels
Fxn of inner cellular layer with chondroblasts
Produce chondrogenic cells which differentiate into chondroblasts secrete matrix and becomes chondrocytes within lacunae
What is the function of perichondrium
Initiates appositional growth and provides nutrition to the cartilage
What is the composition of cartilage
Chondroblasts/chondrocytes in lacuna, ECM (95%), Fibres and ground substance.
What is the composition of fibres of ECM?
Fibres of 3 types (collagen ll, collagen l, elastic) that can be embedded in the matrix, irregular or in bundles.
List down some features of chondroblasts
Young and immature cells
Differentiate into chondrocytes
Flattened shape
One nucleus
Secretes type ll collagen and other ECM components
List down some feature of chondrocytes
Mature cartilage cells in lacuna
Round one or more nucleus (lightly packed so stains lighter)
Cytoplasm has usual organelles, lipid, glycogen inclusions
Abundant RERs
List down some features of hyaline cartilage
Flexible and resilient
Temporary skeleton till its replaced by bone
Type 2 collagen fibres only
Where is hyaline cartilage found
Costal cartilage,articular cartilage, trachea, nose, larynx, bronchii, epiphyseal plate.
Explain features feature of elastic cartilage
Highly bendable
Branching with elastic fibres in between type 2 collagen fibre bundles
Perichondrium rich in elastic fibres
Where is elastic cartilage found
Pinna of ear, internal and external auditory tubes,epiglottis
Explain features of fibrocartilage
Resist compression and tension
Where is fibrocartilage found
In relation to joints, pubic symphysis, intra articular lips, meniscus of knee joint
Explain what happens when cartilage is degenerated
Cells increase in volume and size followed by cell death and calcification of matrix resulting in restricted mobility and joint paint. The regeneration of damaged cartilage is slow and incomplete
What happens when cartilage is damaged
Perichondrium produces a scar of dense connective tissue instead of forming new cartilage
What are the reasons cartilage cant regenerate
Avascularity, immobility of chondrocytes, limited ability to increase in the number or amount of something
List down structural features of hyaline
Isogenous group of cells
Homogenous basophilic matrix
Type 2 collagen fibers only
List down structural features of fibrocartilage
Single or paired chondrocytes alternating with rows of thick collagen fibres
Type 1 collagen dominant
Has no perichondrium
List down features of elastic cartilage
Matrix yellow and more opaque due to elastic fibres
Cells are more scattered
Type 2 collagen fibres branched with elastic fibers
Perichondrium rich in elastic fibers
