Anatomy of Cartilage

Study Notes

Cartilage Overview

Modified connective tissue that is nonvascular, nutrients diffuse from the perichondrium through the matrix.
The perichondrium is a layer rich in blood vessels.

Functions of Cartilage

Provides support to soft tissues.
Acts as a shock absorber due to its resilience.
Smooth surface facilitates sliding, beneficial for joint movement.
Essential for bone growth and development.

Types of Cartilage Cells

Chondroblast:
- Young cartilage cells located beneath the perichondrium.
- Progenitor of chondrocytes, secretes type II collagen and other matrix components.
Chondrocyte:
- Mature cartilage cells that can exist individually or in isogenous groups.
- Reside in spaces called lacunae.

Cartilage Matrix Composition

Provides rigidity, elasticity, and resilience.
Fibers: Composed of collagen and elastic fibers.
Ground Substance: Contains glycosaminoglycans (chondroitin sulfates and keratan sulfate) and water; appears basophilic (stains blue).

Types of Cartilage and Locations

Hyaline Cartilage:
- Locations: Tracheal rings, nasal septum, larynx, costal cartilage, and articular surfaces of joints.
- Features: Cartilage cells present singly or in groups within lacunae, primarily contains collagen type II, basophilic ground substance.
- Functions: Supportive and contributes to the structure of various tissues.
Elastic Cartilage:
- Locations: Auricle, external auditory meatus, auditory tube, epiglottis, and apices of arytenoid cartilage.
- Features: Cells are larger, closely packed with no groups, rich in elastic fibers and collagen type II.
- Functions: Supportive with enhanced flexibility.
Fibrocartilage:
- Locations: Intervertebral discs, pubic symphysis, and articular disc of the temporomandibular (TM) joint.
- Lacks perichondrium.
- Features: Fewer, smaller cells, arranged singly or in rows, contains collagen type I and II, and has acidophilic ground substance.
- Functions: Provides support with significant tensile strength.

Cartilage Growth Mechanisms

Appositional Growth:
- Increases WIDTH by chondroblasts depositing matrix on the surface of existing cartilage.
Interstitial Growth:
- Increases LENGTH via chondrocyte division and matrix secretion from within the lacunae.

Description

This quiz covers the structure, functions, and types of cartilage, a modified connective tissue. It also discusses the perichondrium, blood vessels, and the role of cartilage in supporting soft tissues and providing shock absorption.