Lecture: Anatomy and Physiology of the Skeletal System

Introduction

• Lecture on the adult skeletal system.
• Focus beyond just memorizing bones to include joints and physiology.

Components of the Skeletal System

• Bones
  • 206 bones in total.
• Cartilage and Connective Tissue
  • Helps bones work together.
• Joints
  • More joints than bones in the body.
  • Fundamental for movement.

Function of the Skeletal System

• Body movements occur when muscles contract across joints.
• Important to study different types of movements to understand bones and joints.

Division of the Skeleton

• Axial Skeleton
  • 80 midline bones: Skull, vertebral column, thoracic cage.
  • Skull: 8 cranial and 14 facial bones.
  • Vertebral Column: 33 irregular bones.
  • Thoracic Cage: 12 pairs of ribs and sternum.
• Appendicular Skeleton
  • Upper and lower limbs, pectoral and pelvic girdles.
  • Structurally similar set-up for limbs (one bone, two bones, lots of bones, digits).

Classification of Joints

• Structural Classification
  • Based on material binding bones (fibrous tissue, cartilage, fluid-filled cavity).
• Functional Classification
  • Synarthroses: Immovable joints (e.g., skull bones).
  • Amphiarthroses: Slightly movable joints (e.g., pelvis).
  • Diarthroses: Fully movable joints (e.g., knee, elbow).

Types of Synovial Joints

• Fibrous Joints: Dense fibrous connective tissue, mostly immovable.
• Cartilaginous Joints: Use cartilage, limited movement.
• Synovial Joints: Freely movable, fluid-filled joint cavity.
  • Viscous synovial fluid acts as a lubricant.
  • Six different configurations allowing various body movements.

Movements and Their Classification

• Gliding Movements: Flat bone surfaces glide over each other (e.g., wrist).
• Angular Movements
  • Flexion: Decreases angle between bones.
  • Extension: Increases angle between bones.
  • Hyperextension: Extending beyond normal range.
  • Abduction: Moving limb away from body.
  • Adduction: Moving limb towards body.
  • Circumduction: Circular movement at a joint.
• Rotational Movements
  • Bones rotate around an axis.
  • Ball-and-socket joints allow for rotational movement.
• Special Movements
  • Opposition: Thumb touching fingertips.
  • Supination and Pronation: Rotating palm anteriorly/posteriorly.

Conclusion

• Overview of skeletal system structure and joints.
• Explanation of different joint types and movements.

Additional Information

• Lecture filmed in Dr. Cheryl C. Kinney Crash Course studio.
• Various contributors to the lecture content.