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Cartilage_[Autosaved].pptx
- 1.
- 2. Cartilage Cartilage is aspecialized form of firm and resilient connective tissue that can bear stresses without permanent distortion. It serves as a precursor or model for the embryonic development and subsequent growth of many long bones.
- 3. Structure of theCartilage • It consists of cells • chondroblasts • chondrocytes • extracelluar matrix, consisting of fibers and ground substance (hyaluranan, proteoglycans, glycoproteins).
- 4. Cartilage composition • Cells Chondrocytes:located within matrix; lacunae Chondroblasts: located at periphery; secrete extracellular matrix • Fibers Collagen and elastic fibers • Ground substance Rich in glycosaminoglycans and proteoglycans
- 6. CHONDROBLAST • Progenitor ofchondrocytes • Lines border between perichondrium and matrix • Secretes type II collagen and other ECM components • Chondroblasts build
- 7. CHONDROCYTE • Mature cartilagecell • Reside in a space called the lacuna • Clear areas = Golgi and lipid droplets
- 8. Cells of thecartilage • Chondrocytes completely fill their lacunae • RER and euchromatic nuclei • Synthetically active, secrete matrix
- 9. MATRIX • Provides therigidity, elasticity, & resilience • FIBERS • Collagenous and elastic • GROUND SUBSTANCE • Glycosaminoglycans (chondroitin sulfates, keratin sulfate, hyaluronic acid) • Proteoglycans: GAGs + core protein • Water • Basophilic • Territorial matrix – high conc of sulfated proteoglycans
- 10. CARTILAGE GROWTH • Appositional •Increasing in WIDTH; chondroblasts deposit matrix on surface of pre-existing cartilage • Interstitial • Increasing in LENGTH; chondrocytes divide and secrete matrix from w/in lacunae
- 11. Cartilage composition Perichondrium • Perichondriumis a layer of dense irregular connective tissue. • It is essential for the growth and maintenance of cartilage. • Dense irregularly arranged connective tissue (type I collagen) • Ensheaths the cartilage • Houses the blood vessels that nourish chondrocytes
- 12. Features of Cartilage •Avascular; • Nutrients diffusion from perichondrium or synovial fluid; • No innervation; • No lymphatic vessels; • Chondrocytes have low metabolic activity
- 13. TYPES OF CARTILAGE •HYALINE • ELASTIC • FIBROUS
- 14. Types of Cartilage •Hyaline cartilage: most common, much type II collagen • Elastic cartilage: elastic fibers • Fibrocatilage: dense network of type I collagen
- 15. Hyaline Cartilage • FUNCTION •Support tissue and organs • Model for bone development • MATRIX • Type II collagen (thin fibrils) • Chondroitin sulfate, keratin sulfate, hyaluronic acid • Water • LOCATION • Tracheal rings, nasal septum, larynx, articular surfaces of joints, ends of the ribs
- 16. Hyaline Cartilage • Chondrocytespresent in groups of 4 to 8 cells • Cell nests ( isogenous aggregates) • Teritorial matrix lacunar capsule :- deeply stained matrix • interstitial matrix
- 18. ELASTIC CARTILAGE • FUNCTION •Support with flexibility • MATRIX • Normal components of hyaline matrix plus ELASTIC fibers • LOCATION • External ear, external auditory canal, epiglottis, laryngeal cartilage (corniculate and cuneiform) • STAINS • Elastic fibers stain BLACK with Weigert stain
- 19. Elastic Cartilage • Yellowcartilage • Covered by perichondrium NOTE: Elastic cartilage is located in sites associated with production and or reception of sound.
- 21. Fibrocartilage • FUNCTION • Supportwith great tensile strength • MATRIX • Type I collagen - Oriented parallel to stress plane • LOCATION • Intervertebral disks, pubic symphysis
- 22. Fibrocartilage • White fibrocartilage •Looks like dense fibrous tissue • Chondrocytes occur singly in the lacunar • No distinct surrounding perichondrium NB; Fibrocartilage is associated with structures in the midline of the body.
- 24. Applied Anatomy • Hyalinecartilage is susceptible to calcification during aging • Oesteoarthritis, a chronic condition during aging affect hyaline cartilage in joints • Cartilage inability to full repair due to its avascularity • Tumours of the cartilage Chondromas chondrosarcomas