Unit 4.1 Cartilage Tissue PDF

OUTLINE 4.1. Cartilaginous tissue. 4.1.1. General characteristics. 4.1.2. Types. Hyaline cartilage. Elastic cartilage. Fibrocartilage. 4.1.3. Growth and repair. © Copyright Universidad Europea. Todos los derechos reservados REPAIR AND GROWTH Mesenchyme Precartilaginous condensation Cartilage m...

OUTLINE 4.1. Cartilaginous tissue. 4.1.1. General characteristics. 4.1.2. Types. Hyaline cartilage. Elastic cartilage. Fibrocartilage. 4.1.3. Growth and repair. © Copyright Universidad Europea. Todos los derechos reservados REPAIR AND GROWTH Mesenchyme Precartilaginous condensation Cartilage model Most cartilage originates from the mesenchyme during chondrogenesis. Chondrogenesis, the process of cartilage development, begins when chondroprogenitor mesenchymal cells cluster together to form a dense mass of rounded cells. © Copyright Universidad Europea. Todos los derechos reservados REPAIR AND GROWTH Repair and growth are slow processes: avascular. Interstitial growth: New cartilage formation process INSIDE a preexisting cartilage. - Chondrocytes divide and form a new matrix. - It continues in childhood and adolescence (in specific places *). Appositional growth: New cartilage formation process ON the surface of a preexisting cartilage. - Chondroblasts secrete matrix to the surface (accumulation under the perichondrium). - Cartilage growth across. - Continue in adolescence. © Copyright Universidad Europea. Todos los derechos reservados REPAIR AND GROWTH • Interstitial growth: In the region where cartilage is being FORMED, individual mesenchymal cells in the embryo change to a rounded shape and congregate in masses called chondrification centers. MITOSIS=+MATRIX, cells in LACUNAE. LACUNAE with 2-4 cells: ISOGENOUS GROUPS. © Copyright Universidad Europea. Todos los derechos reservados These cells differentiate into CHONDROBLASTS and can DIVIDE. REPAIR AND GROWTH In the DEVELOPING cartilage, mesenchymal cells differentiate to fibroblasts, generating the perichondrium. The fibrous (external) fibroblast layer synthesizes the collagenous irregular dense connective tissue. The (internal) cell layer is made up of chondrogenic cells that divide and differentiate into chondroblasts. Thus, cartilage also grows by accumulating matrix beneath the perichondrium, a process called appositional growth. © Copyright Universidad Europea. Todos los derechos reservados Complete the sentences Cartilage grows in length by _________________ growth. In this type of growth, the cells that divide are the ___________________. Cartilage grows in width by _________________ growth. In this type of growth, the cells that divide are the ___________________. © Copyright Universidad Europea. Todos los derechos reservados 34 FUNCTIONS of CARTILAGE Mechanical: SUPPORT (resists tension, compression and shear). Structural: flexibility and elasticity (resilience). Bone growth: precursor to bone. Forms the embryonic skeleton. Allows longitudinal growth of long bones. © Copyright Universidad Europea. Todos los derechos reservados