Lecture on Skeletal System and Joints
Introduction
- Skeletal system is complex; more than just bones
- Includes cartilage and fibrous connective tissue
- Physiology involves joints and movements
Skeletal System Overview
- Axial Skeleton: 80 bones including skull, vertebral column, thoracic cage
- Skull: 8 cranial bones, 14 facial bones
- Vertebral Column: 33 irregular bones, starting with the atlas vertebra
- Thoracic Cage: 12 pairs of ribs, sternum
- Appendicular Skeleton: Upper and lower limbs, pectoral and pelvic girdles
- Similar setup in limbs: one bone, two bones, lots of bones, and digits
Joints: Meeting Places of Bones
- Joints exceed in number compared to bones
- Types of joints based on function and structure
Functional Classification of Joints
- Synarthroses: Immovable joints (e.g., skull bones)
- Amphiarthroses: Slightly movable joints (e.g., pubic symphysis)
- Diarthroses: Fully movable joints (e.g., knee, elbow)
Structural Classification of Joints
- Fibrous Joints: Immovable, dense connective tissue
- Cartilaginous Joints: Use cartilage, slightly movable
- Synovial Joints: Freely movable, fluid-filled cavity
- Contain synovial fluid as lubricant
Synovial Joint Movements
- Gliding: Flat bone surfaces glide over each other (e.g., wrist joints)
- Angular Movements: Change angle between bones
- Flexion: Decrease angle (e.g., bending arm)
- Extension: Increase angle
- Hyperextension: Extend beyond normal range
- Rotational Movements: Bone rotates around its axis
- Abduction: Move limb away from body
- Adduction: Move limb toward body
- Circumduction: Circular movement combining flexion, extension, abduction, and adduction
- Special Movements (unique)
- Opposition: Thumb touches other fingers
- Supination: Palm faces forward
- Pronation: Palm faces backward
Conclusion
- Overview of skeletal structure and joint classifications
- Types of movements facilitated by joints
- Thanks to contributors and supporters of the educational content
Acknowledgements
- Episode by Crash Course, contributions from Patreon patrons
- Filmed at Dr. Cheryl C. Kinney Crash Course studio
- Written by Kathleen Yale, edited by Blake DeBestino, consultant Dr. Brandon Jackson
- Production team and contributors acknowledged
This summary provides an understanding of the skeletal system's structure, joint classifications, and movements without relying on simplistic songs or concepts. It offers insights into anatomy and physiology in an engaging manner.