Lecture Notes: Understanding Your Skeletal System

Introduction

• Lecture begins with a humorous note on teaching skeletal systems to kindergartners.
• Skeletal system includes more than just bones:
  • Cartilage and fibrous connective tissue
  • Importance of joints

Overview of the Skeletal System

• Skeleton divided into two major parts:
  • Axial Skeleton
    • Includes 80 midline bones
    • Comprises skull, vertebral column, thoracic cage
    • Skull's 8 cranial and 14 facial bones
    • Vertebral column with 33 irregular bones starting at the atlas vertebra
    • Thoracic cage includes 12 pairs of ribs and sternum
  • Appendicular Skeleton
    • Includes upper and lower limbs
    • Pectoral and pelvic girdles
    • Both limbs have a 'one bone, two bones, lots of bones, and digits' structure

Physiology of the Skeleton: Joints

• Classification of joints:
  • Structural Classification
    • Based on material bonding bones (fibrous, cartilage, synovial)
  • Functional Classification
    • Based on movement capacity (synarthroses, amphiarthroses, diarthroses)
• Types of Joints
  • Fibrous joints: immovable, e.g., skull sutures
  • Cartilaginous joints: limited movement, lack joint cavity
  • Synovial joints: freely movable, have a fluid-filled joint cavity
    • Six configurations enabling various body movements

Movement and Joint Functions

• Types of Movements
  • Gliding movements
  • Angular movements: flexion, extension, hyperextension
  • Abduction and adduction
  • Circumduction
  • Rotational movements
  • Special movements: opposition (thumbs), supination, pronation
• Joint Designs
  • Ball and socket joints (e.g., hip, shoulder)
  • Saddle joints (thumb)
  • Pivot joints (radius, ulna)

Conclusion

• Emphasis on learning about skeletal structure and joint movement.
• Mention of Crash Course contributors and production team.

Additional Information

• Lecture was lighthearted, using examples like dancing to explain concepts.
• Encouragement to explore more educational resources through Crash Course.