Musculoskeletal System Review

Musculoskeletal System Review

• The musculoskeletal system includes bones, muscles, cartilage, tendons, ligaments, and connective tissues.
• It supports the body's structure and enables movement.
• It's vital for providing form, stability and movement.
• It plays roles in mineral storage, hematopoiesis, and protection of internal organs.

Components of the Musculoskeletal System

A. Bones

• Structure: Rigid organs composed of osseous tissue, bone marrow, nerves, and blood vessels.
• Function:
  • Support: Provides the framework of the body.
  • Protection: Shields vital organs (e.g., skull protects the brain).
  • Movement: Serves as levers for muscles.
• Mineral Storage: Reservoir for calcium and phosphorus.
• Hematopoiesis: Blood cell production in the bone marrow.
• Bones support body weight and allow resistance during physical activity, maintaining homeostasis of minerals crucial for nerve and muscle function.

B. Joints

• Structure: Articulations where bones meet.
• Types: Various types of joints exist including synarthrosis (immovable), amphiarthrosis (slightly movable), and diarthrosis (freely movable).

C. Cartilage

• Structure: Flexible connective tissue composed of chondrocytes.
• Types:
  • Hyaline Cartilage: Reduces friction (e.g., ends of long bones).
  • Elastic Cartilage: Provides flexibility (e.g., external ear).
  • Fibrocartilage: Resists compression (e.g., intervertebral discs).
• Function: Acts as a cushion and structural component in joints and other parts.
• Prevents bone erosion and distributes stress during weight-bearing activities.

D. Muscles

• Structure: Composed of muscle fibers bundled into fascicles.
• Types:
  • Skeletal Muscle: Voluntary, striated; enables movement.
  • Smooth Muscle: Involuntary, non-striated; found in internal organs.
  • Cardiac Muscle: Involuntary, striated; unique to the heart.
• Function:
  • Movement: Contraction and relaxation generate force.
  • Posture: Maintain body position.
  • Heat Production: Thermogenesis during muscle activity.

Musculoskeletal Physiology

A. Bone Remodeling

• Bone remodeling is a continuous cycle of bone resorption (osteoclasts) and formation (osteoblasts).
• Its purpose is to adapt to stress (e.g., weight-bearing activities), repair microdamage, and maintain mineral balance.
• This ensures bones remain strong and responsive to physical demands.

B. Muscle Contraction

• Mechanism: Sliding filament theory.
  • Excitation: Neural signal triggers calcium release in muscle cells.
  • Coupling: Calcium binds to troponin, exposing active sites on actin.
  • Contraction: Myosin heads bind to actin, pulling filaments for muscle shortening.
  • Relaxation: ATP restores myosin to resting state.
• Effective contraction depends on calcium, ATP, and intact neuromuscular signaling for precise movement and posture.

C. Joint Function

• Synovial Fluid: Lubricates joints, reduces friction, and nourishes cartilage.
• Load Distribution: Joints absorb and distribute mechanical forces.
• Prevents joint degeneration and ensures smooth movement during activities.

Laboratory and Diagnostic Findings

• The musculoskeletal system's assessment involves tests and imaging studies to evaluate bone, muscle, joint, and connective tissue health.
• These findings aid in diagnosing disorders, monitoring disease progression, and evaluating treatment efficacy.
• Specific laboratory tests (e.g., serum calcium and phosphorus, alkaline phosphatase, vitamin D, creatine kinase) and imaging studies (e.g., X-ray, MRI, DEXA, CT scan, ultrasound) are used for analyses.

Other Diseases (examples)

• Osteoarthritis (OA): Degenerative joint disease or osteoarthrosis.
• Rheumatoid Arthritis (RA): Autoimmune disorder.
• Gout: Condition related to a genetic defect of purine metabolism.
• Septic arthritis: Infectious arthritis.

Additional Information (examples)

• Medical Management and Nursing Management (for specific diseases): Treatment strategies and required nursing interventions are diverse and specific for each disease.
• Diagnosing methods, including diagnostic procedures, imaging, and laboratory tests are crucial considerations.
• Risk factors and prevention strategies for each disease need to be specific and well-defined.
• Symptoms specific for the diseases are important details for a comprehensive overview.