ZOO 3000 Lecture Notes - Lecture 4: Ground Substance, Trachea, Osteoclast

• School: University of Guelph
• Department: Zoology
• Course: ZOO 3000
• Professor: Fred Laberge

Document Summary

Specialized connective tissues with a hard matrix: cartilage ground substance with highly charged proteoglycan aggregates, making ecm hard and pliable, bone calcified matrix (capo4), making ecm hard and rigid. Lacunae a cavity or depression; an unfilled space or gap. Embedded chondroblasts become chondrocytes, divide and produce more ground substance and fibres. Interstitial: appositional, new cartilage at the surface of existing cartilage, derived from perichondrium. Types of cartilage: distinguished by fibrous matrix composition, 3 types, hyaline cartilage, elastic cartilage, fibrocartilage. From hyalos greek for glass translucent when fresh. Function: low frictional surface, flexibility, cushioning, where, articular surfaces of joints, trachea and bronchi, chondrocytes in lacunae. F"17: darker near lacunae because secreted proteoglycans are basophilic, matrix is mostly water, contains type 2 collagen, proteoglycans and multiadhesive glycoproteins. The charged proteoglycan aggrecan responsible for hydration: matrix is avascular, nutrients diffuse from blood vessels in perichondrium or bone, has very low potential for repair and calcifies with age.