Cartilage Flashcards
What is the composition of the cartilage matrix?
Glycosaminoglycans and type II collagen (hydrated matrix)
Proteoglycans bound to hyaluronic acid -> hyaluronate proteoglycan aggregate
What is the definition of cartilage?
Avascular tissue consisting of an extensive extracellular matrix in which lies chrondrocytes (which secrete and maintain the extracellular matrix)
What is the structural difference between hyaline, elastic, and fibrocartilage?
HYALINE = proteoglycans, hyaluronic acid, type II collagen
ELASTIC = proteoglycans, hyaluronic acid, type II collagen + elastic fibres & elastic lamellae
FIBROCARTILAGE = proteoglycans, hyaluronic acid, type II collagen + type I collagen
Where is hyaline cartilage found? What are some important features?
Articulating surfaces = surface of joint where ends of bone meets
e.g. ribcage, nose, trachea, bronchi, larynx
Undergoes endochondral ossification (mineralisation) - but some remains at articulating surfaces/epiphyseal plate
Perichondrium covers hyaline cartilage at non-articulating surfaces
Chondrocytes lie in lacunae. Pressure loads applied directs synthetic activity of the chondrocytes
What is the perichondrium?
Layer of dense fibrous connective tissue covering hyaline cartilage at non-articulating surfaces which contains fibroblast-like cells which can develop into chondroblasts and then chondrocytes
Where is elastic cartilage found? What are some of its important features?
Found at pinna (external ear), the external acoustic meatus (auditory canal), epiglottis, the Eustachian tube (tube connecting inner ear to nasal cavity)
Does not calcify with age
Where is fibrocartilage found? What are some of its important features?
Found at points of attachment of tendon and bone, the intervertebral discs, the articular discs of the sternoclavicular and temporomandibular joints, the menisci of the knee joint, pubic symphysis
Dense regular connective tissue + hyaline cartilage
No perichondrium
What is the origin of cartilage?
Mesenchyme
