Muscular System Flashcards
(20 cards)
Anatomy of the Muscular System
Skeletal Muscle: Striated, voluntary, attached to bones.
Cardiac Muscle: Striated, involuntary, found in the heart.
Smooth Muscle: Non-striated, involuntary, found in walls of hollow organs.
Functions of the Muscular System
Movement: Enables voluntary and involuntary movement.
Posture: Maintains body posture and stability.
Heat Production: Generates heat through muscle contractions.
Joint Stability: Stabilizes joints and supports skeletal system.
Skeletal Muscle Structure
Muscle Fiber: Individual muscle cell; multinucleated.
Fascicle: Bundle of muscle fibers.
Connective Tissue Layers:
- Epimysium (surrounds entire muscle)
- Perimysium (surrounds fascicles)
- Endomysium (surrounds individual fibers)
Tendon: Connects muscle to bone.
Muscle Contraction Mechanism
Sliding Filament Theory: Actin and myosin filaments slide over each other during contraction.
Steps:
1. Nerve Impulse: Triggers release of calcium ions.
2. Cross-Bridge Formation: Myosin heads attach to actin filaments.
3. Power Stroke: Myosin pulls actin, shortening the muscle.
4. Relaxation: Calcium is reabsorbed, and muscle returns to resting state.
Types of Skeletal Muscle Fibers
Type I Fibers (Slow-twitch):
Resistant to fatigue, used for endurance activities.
High myoglobin content, rich in capillaries.
Type II Fibers (Fast-twitch):
Fatigue quickly, used for short bursts of power.
Lower myoglobin, fewer capillaries.
Major Skeletal Muscles
Deltoid: Shoulder muscle; responsible for arm abduction.
Biceps Brachii: Front of the upper arm; flexes elbow.
Triceps Brachii: Back of the upper arm; extends elbow.
Quadriceps: Front thigh; extends knee.
Hamstrings: Back thigh; flexes knee.
Muscle Actions
Agonist (Prime Mover): Main muscle responsible for movement.
Antagonist: Opposes the action of the agonist.
Synergist: Assists the agonist in performing its action.
Fixator: Stabilizes the origin of the agonist.
Muscular System Disorders
Muscular Dystrophy: Genetic disorders causing muscle weakness and degeneration.
Myasthenia Gravis: Autoimmune disorder affecting neuromuscular transmission, leading to muscle weakness.
Rhabdomyolysis: Breakdown of muscle tissue releasing myoglobin into the bloodstream; can cause kidney damage.
Tendonitis: Inflammation of a tendon due to overuse.
Muscle Injury and Healing
Common Injuries: Strains (overstretching or tearing) and sprains (ligament injury).
Healing Process:
- Inflammatory Phase: Swelling and pain; body initiates healing.
- Repair Phase: New tissue formation.
- Remodeling Phase: Tissue matures and strengthens.
Nutrition for Muscle Health
Proteins: Essential for muscle repair and growth (e.g., lean meats, beans, dairy).
Carbohydrates: Primary energy source for muscle function (e.g., whole grains, fruits).
Fats: Healthy fats support hormone production and energy (e.g., avocados, nuts).
Hydration: Essential for optimal muscle function and recovery.
Assessing Muscle Strength
Manual Muscle Testing (MMT): Evaluate strength against resistance.
Grading Scale:
0: No muscle contraction
1: Trace contraction
2: Full ROM (range of motion) with gravity eliminated
3: Full ROM against gravity
4: Full ROM against some resistance
5: Full ROM against full resistance (normal strength)
Flexibility and Stretching
Importance: Enhances range of motion, reduces risk of injury, and improves performance.
Types of Stretching:
- Static Stretching: Holding a stretch for 15-60 seconds.
- Dynamic Stretching: Controlled movements that improve flexibility.
- Proprioceptive Neuromuscular Facilitation (PNF): Stretching technique combining contraction and relaxation.
The Role of Exercise in Muscle Health
Types of Exercise:
- Resistance Training: Builds muscle strength and mass.
- Aerobic Exercise: Improves cardiovascular endurance; supports muscle function.
- Balance and Coordination Training: Enhances functional movement and prevents falls.
Frequency: At least 150 minutes of moderate exercise per week recommended.
Muscle Spasms and Cramps
Muscle Spasm: Involuntary contraction; often painful and temporary.
Causes: Dehydration, electrolyte imbalances, overuse, or injury.
Management: Stretching, hydration, warm compresses, and rest.
Postural Assessment
Importance: Evaluates alignment and muscle balance; identifies potential issues.
Key Components:
- Head alignment over shoulders.
- Shoulders level and relaxed.
- Spine curvature: normal lordosis, kyphosis, or scoliosis.
- Hips aligned with knees and ankles.
Muscle Tone
Definition: Continuous and passive partial contraction of the muscles.
Normal Tone: Maintains posture and allows for quick response to stimuli.
Hypotonia: Decreased muscle tone; may indicate neurological issues.
Hypertonia: Increased muscle tone; may indicate spasticity or rigidity.
Aging and the Muscular System
Sarcopenia: Age-related loss of muscle mass and strength.
Factors Contributing to Muscle Changes: Decreased activity, hormonal changes, nutritional deficiencies.
Impact on Function: Increased risk of falls, decreased mobility, and reduced quality of life
Rehabilitation and Physical Therapy
Goals: Restore strength, flexibility, and function after injury or surgery.
Techniques:
- Exercise prescription tailored to individual needs.
- Manual therapy (e.g., massage, joint mobilization).
- Education on body mechanics and injury prevention.
Ergonomics and Musculoskeletal Health
Definition: Study of how people interact with their environment to improve efficiency and reduce injury.
Importance: Prevents musculoskeletal injuries in the workplace and daily activities.
Key Principles: Proper posture, appropriate workstation design, and lifting techniques.
Patient Education on Muscle Health
Exercise Recommendations: Encourage regular strength and flexibility training.
Ergonomics: Teach proper lifting techniques and workspace setup.
Nutritional Guidance: Emphasize balanced diet rich in protein and hydration.
Awareness of Symptoms: Educate about recognizing signs of muscle injuries or disorders.
