Connective Tissue Types Cartilage Dr. Jack L. Haar Department of Anatomy Sanger Hall 9-064

Cartilage General considerations Light, flexible, much intercellular substance Forms quickly Nutrients supplied by diffusion, no blood vessels

B. Embryology Forms very early in development

Histological components Cells Chondroblasts Come from mesenchymal cells or multipotential C.T. cells Differentiate to produce cartilage matrix

Chondrocyte (mature cartilage cell) Located in lacunae Golgi, rER , fat droplet possible

Intercellular matrix Fiber type depends on type of cartilage Ground substance, mainly chondroitin sulfate Territorial and interterritorial matrix

Perichondrium Fibrous layer of dense C.T. Chondrogenic layer of chondroblasts

Perichondrium (cartilage is non-vascular)

Growth of cartilage Appositional Interstitial

Types of cartilage. Hyaline Cartilage – type II collagen Types of cartilage Hyaline Cartilage – type II collagen Distribution: nose larynx, strachea, bronchi

Elastic Cartilage Abundant elastic fiber Branching network Limited ground substance

Distribution External ear, epiglottis, part of the larynx

Fibrocartilage “Never occurs alone but blends insensibly with neighboring hyaline cartilage, fibrous tissue or bone” Fiber component Bundles of collagen type I fibers fill matrix Chondrocytes May appear in parallel rows or randomly distributed Occur in lacunae Minimal ground substance Function: strength and transition

Function:. Provides stiffness and great tensile strength at tendon Function: Provides stiffness and great tensile strength at tendon insertions

Function:. A transition form from dense FECT and cartilage, provides Function: A transition form from dense FECT and cartilage, provides shock absorption

Distribution Intervertebral disc Annulus fibrosus Nucleus pulposus

Distribution Pubic symphysis Tendons to bones

Regressive changes in cartilage. a Regressive changes in cartilage a. Chondrocytes greatly hypertrophy, produce alkaline phosphatase, a calcifiable matrix; b. Calcium phosphate is deposited in matrix; does not allow diffusion of nutrients c. Chondrocytes die leaving behind the calcified matrix

Occurrence. a. In some cartilage as it ages. b Occurrence a. In some cartilage as it ages b. As early stage of bone production

http://www. path. uiowa. edu/virtualslidebox/ Table of Contents http://www.path.uiowa.edu/virtualslidebox/ Table of Contents Supporting tissue and muscle Hyaline cartilage #5 Elastic cartilage #7 http://java.vcu.edu/som-histology/