Week 2 Spine, Limbs, & Joints脊柱、四肢和关节

• Week 2.1 Class: Spine, Limbs, & Joints
• Course Number: HSCI 10280
• Semester: Winter 2025
• Institution: Mohawk College

Functions of the Skeleton

• Supports the body through the legs and pelvic girdle
• Protects soft body parts: skull protects the brain, ribcage protects the heart and lungs, vertebrae protect the spinal cord
• Produces blood cells via red bone marrow
• Stores minerals like calcium and phosphate, as well as fat
• Facilitates movement by serving as attachment points for muscles

Bone Structure

• Compact Bone (Dense): Highly organized, composed of osteons, densest and strongest type, primarily found in the shaft of long bones, provides protection, support, and resistance to external pressure
• Spongy Bone (Cancellous): Resembles lightweight but strong steel beams, located at the ends of long bones (epiphysis), lightweight but structurally strong

Bone Remodeling

• Bones are constantly changing and remodeling.
• Repairs minor cracks
• Responds to stress, such as weight training
• 5-7% of bone mass is recycled weekly
• Spongy bone is replaced every 3-4 years
• Compact bone is replaced approximately every 10 years.

Bone Cells

• Osteoblasts: Form new bone tissue.
• Osteoclasts: Break down old bone tissue.
• Osteocytes: Maintain bone structure; derived from osteoblasts.

Blood Cell Formation

• Blood cells live for only about 180 days
• New blood cells are generated within the red bone marrow

Axial vs. Appendicular Skeleton

• Axial Skeleton: Midline of the body, consisting of the skull, spine, ribs, and sternum
• Appendicular Skeleton: Includes the limbs and their connecting structures (girdles)

Joints & Ligaments

• Joints Function: Connect bones and enable movement.
• Ball-and-Socket Joints: Shoulder, hip.
• Hinge Joints: Elbow, knee.
• Pivot Joints: Allow radius to rotate around ulna
• Condylar Joints: Jaw.
• Saddle Joints: Carpometacarpal joint of the thumb.
• Ligaments: Connect most bones to maintain stability, primarily composed of collagen fibers, stronger with more fibers
• Vertebral Column: commonly known as the spine

Common Joint Disorders

• Osteoarthritis: Most common chronic arthritis, inflammation due to joint damage, related to aging, but not everyone experiences it
• Rheumatoid Arthritis: Autoimmune disorder where the immune system attacks joint tissues, causes bilateral joint inflammation, potentially leading to deformities
• Joint Injuries: Dislocations occur when the joint is pulled out of the socket and sprains are a tear of ligaments

Vertebral Column Details

• Consists of 7 cervical, 12 thoracic, and 5 lumbar vertebrae
• Intervertebral Discs: Situated between vertebrae to absorb shock and permit spinal movement.
• Herniated Disc: When the disc protrudes, it presses on nerves, causing pain

Spinal Curvatures

• Scoliosis: Lateral curvature of the spine.
• Thoracic Kyphosis: Excessive outward curvature of the thoracic spine.
• Lumbar Lordosis: Excessive inward curvature of the lumbar spine.

Structure of a Vertebra

• Vertebral body
• Vertebral arch
• Vertebral foramen
• Transverse process
• Spinous process
• Articulating processes and facets

Thoracic Cage

• Sternum: Consists of the manubrium, body, and xiphoid process
• Ribs: True ribs, false ribs, and floating ribs

Upper Limb Bones

• Clavicle
• Scapula
• Humerus: Features include the head, anatomical neck, greater and lesser tubercle, bicipital groove, deltoid tuberosity, medial and lateral epicondyles
• Radius & Ulna: Includes head of radius, olecranon process of ulna

Hand Bones

• Carpals: 8
• Metacarpals: 5
• Phalanges: 14

Lower Limb Bones

• Femur: Notable features include the head, neck, greater and lesser trochanter, gluteal tuberosity, medial & lateral condyles
• Tibia & Fibula: Key features include the tibial tuberosity, medial malleolus, and lateral malleolus
• Foot Bones: Tarsals: 7 (including talus and calcaneus), Metatarsals: 5, Phalanges: 14

Joint Functions and Types

• Joint Functions: Hold bones together and allow for mobility.
• Types of Joints: Classified structurally and functionally.
• Ligaments: Composed of tough, flexible tissue; they provide stability during movement
• Articular Cartilage: Provides a smooth surface to reduce friction, and distributes loads to protect bones
• Synovial Joints: Composed of articular cartilage covering bone ends, articular capsule enclosing joint surfaces lined with synovial membrane, joint cavity containing synovial fluid, reinforcing ligaments, and muscles
• Types of Joints: Ball and Socket (Shoulder and Hip), Hinge (Elbow and Knee),
• Pivot (Radius rotates around ulna), Condylar (Jaw), Saddle (Carpometacarpal joint of the thumb), Plane (Between ribs and vertebrae)