Skeletal System-Bone Tissue.pptx

Skeletal System Overview

Introduction

  • The skeletal system includes bones, cartilages, and joints.

Functions of the Skeletal System

  • Support: Provides structure to the body.

  • Protection: Shields vital organs.

  • Movement: Works with muscles to allow movement.

  • Storage: Holds minerals and fats.

  • Endocrine Regulation: Participates in hormone production.

  • Blood Cell Production: Hosts locations for hemopoiesis.

  • Joint Functionality: Allows angular movements and structural stability.

Components of the Skeletal System

  • Cartilages: Various types, including hyaline, elastic, and fibrous.

  • Bones: The primary building blocks of the skeletal system.

  • Joints: Areas where bones connect and movement occurs.

Types of Cartilage

  • Hyaline Cartilage: Most abundant; provides support and flexibility. Found in articular surfaces, costal areas, and respiratory structures.

  • Elastic Cartilage: Similar to hyaline but with more elastic fibers, found in structures like the ear and epiglottis.

  • Fibrocartilage: Stronger, resists compression; found in intervertebral discs and knee menisci.

Growth of Cartilage

  • Appositional Growth: Growth from the outside; chondroblasts in the perichondrium secrete new matrix.

  • Interstitial Growth: Growth from within; existing chondrocytes divide and secrete new matrix.

Bone Classification

  • By Location:

    • Axial Skeleton: Skull, vertebral column, rib cage (80 bones).

    • Appendicular Skeleton: Limbs and girdles (126 bones).

  • By Shape:

    • Long Bones: Longer than wide (e.g., femur).

    • Short Bones: Cube-shaped (e.g., wrist bones).

    • Flat Bones: Thin and slightly curved (e.g., sternum).

    • Irregular Bones: Complex shapes (e.g., vertebrae).

    • Special Bones: Sutural and sesamoid bones (e.g., patella).

Composition of Bone

  • Chemical Makeup: 2/3 inorganic minerals (mainly calcium), 1/3 organic compounds (mostly collagen).

  • The presence of both provides strength and flexibility to bones.

Structure of Bone

Long Bone Structure

  • Diaphysis: Shaft with a medullary cavity.

  • Epiphyses: Expanded ends filled with spongy bone and covered by articular cartilage.

  • Membranous covering: Periosteum and endosteum manage bone health and remodeling.

Bone Cells

  • Osteogenic Cells: Stem cells that become osteoblasts.

  • Osteoblasts: Cells that form new bone.

  • Osteocytes: Mature bone cells maintaining bone matrix.

  • Osteoclasts: Cells that resorb bone matrix.

Microscopic Anatomy of Bone

  • Compact Bone: Comprised of osteons, concentric and interstitial lamellae, central canals.

  • Spongy Bone: Contains trabecular networks, lacks osteons, aligns according to stress lines.

Conclusion

  • Understanding the skeletal system's key aspects is crucial for recognizing its role in overall health and movement.