Biology Chapter on Muscle Types and Functions

Scientific Method Steps

• Observation
• Question
• Hypothesis
• Prediction
• Experiment
• Analysis
• Conclusion

Muscle Fiber Types

• Type I (Slow-twitch):

  • Dark red color
  • Fatigue resistant
  • Used in low-intensity, long-duration activities (e.g., marathon running, endurance cycling)

• Type IIa (Fast-twitch oxidative):

  • Red/pink color
  • Fast twitch, fatigue resistant
  • Used in medium-intensity, medium-duration activities (e.g., sprinting, swimming)

• Type IIx (Fast-twitch glycolytic):

  • White color
  • Fast twitch, fatigues quickly
  • Used in high-intensity, short-duration activities (e.g., powerlifting, weightlifting)

Muscle Types and Function

• Cardiac Muscle: Involuntary – pumps blood continuously.
• Skeletal Muscle: Voluntary – responsible for movement.
• Smooth Muscle: Involuntary – found in internal organs, controls processes like digestion.

Ligaments vs. Tendons

• Ligaments: Connect bone to bone.
• Tendons: Connect muscle to bone.

Muscle Fiber Components

• Myofibrils
• Sarcomeres
• Actin and Myosin filaments
• Sarcoplasmic Reticulum
• Transverse Tubules

Energy Balance and Weight Management

• Energy Balance: Intake vs. expenditure – a surplus leads to weight gain, a deficit to weight loss.

• BMR (Basal Metabolic Rate): Energy used for basic body functions at rest

Healthy Diet Characteristics

• Limit: Processed foods, sugary drinks, saturated and trans fats, excessive sodium, unhealthy oils and alcohol
• Include: Fruits, vegetables, whole grains, lean proteins, healthy fats (e.g., avocados, nuts, olive oil). Water.

AMDR (Acceptable Macronutrient Distribution Ranges)

• Recommended ranges of carbohydrate, protein, and fat intake for optimal health.

Food Label Monitoring

• Avoid: High sugar content, excessive sodium.
• Strive for: High fiber, lean protein, healthy fats.

Beneficial Nutrients and Vitamins

• Carbohydrates: Choose complex carbohydrates over simple ones.
• Vitamins: Essential for various bodily functions.

Pulmonary and Cellular Respiration

• Pulmonary Gas Exchange: Occurs in the alveoli of the lungs.
• Cellular Respiration: Occurs in the mitochondria of cells.

ATP Production

• Anaerobic Glycolysis: Fastest, produces a small amount of ATP from glucose without oxygen.
• Aerobic Glycolysis: Slower, produces a large amount of ATP from glucose with oxygen.
• Oxidation of FFAs (Free Fatty Acids): Slowest, produces more overall ATP than glucose.

Oxidative System Fuel Sources

• Can use carbohydrates and fats.

American Heart Association's "Life's Essential 8"

• Components meant to improve/prevent cardiovascular health and disease.

Mediterranean Diet Food Types

• Fruits, vegetables, whole grains, legumes, olive oil, fish.

Good vs. Bad Fats

• Good Fats: Unsaturated fats (monounsaturated and polyunsaturated) e.g., olive and canola oils, nuts.
• Bad Fats: Saturated and trans fats, typically from processed foods and animal products.

Muscle Performance Types

• Strength: Ability to exert max force
• Endurance: Ability to sustain force over time
• Power: Rate of exertion force in a given time.

Cardiovascular Measures

• Stroke Volume: Volume of blood pumped per beat (ml/beat).
• Cardiac Output: Amount of blood pumped per minute (liters/minute).
• Ejection Fraction: Percentage of blood pumped out per beat (%).

Heart Pacemaker and Rate

• Sinoatrial (SA) node: Natural pacemaker.
• Firing rate = 60-100 beats per minute.

Diaphragm Shape

• Inhalation: Flattened
• Exhalation: Dome-shaped

Breathing Changes During Exercise

• Tidal Volume: Increase
• Breathing Frequency: Increase

Capillaries, Arteries, and Veins

• Capillaries: Tiny blood vessels for gas and nutrient exchange. Crucial for oxygen delivery and waste removal.
• Arteries: Carry blood away from the heart.
• Veins: Carry blood back to the heart.

Exercise Guidelines

• Aerobic: 150 minutes moderate intensity or 75 minutes vigorous intensity per week.
• Resistance: 2 or more days per week.

Sustainability Definition

• Meeting needs of the present without compromising the ability of future generations to meet their own needs

Carbon and Nitrogen Footprint Risks

• Climate change, environmental damage.

Exercise in Heat Effects

• Heart Rate: Increase
• Stroke Volume: Decrease initially, then potentially increase
• Core Temperature: Increase

Exercise Intensity and Cardiovascular Benefit

• Moderate-intensity exercise benefits most.

Overtraining Syndrome (OTS) Symptoms

• Fatigue, decreased performance, mood changes, etc.

Aerobic Training Benefits

• Increased heart rate, stroke volume, and cardiac output (likely increase).

Oxygen Consumption

• Measure of oxygen used during activity.
• VO2 Max: Maximum oxygen consumption during exercise, a measure of cardiovascular fitness.

Athlete Reaching VO2 Max

• Athletes are still capable of running even faster, though not using oxygen faster.

Training Principles

• Specificity, Progressive Overload, Reversibility, Individuality, Variation

Resting and Maximal Heart Rate Changes with Training

• Resting HR: Decreased
• Maximal HR: No change or possible small decrease

Cardiovascular Health (AHA) Definition

• Comprehensive approach covering various physiological components of the heart and blood vessels

Muscular Adaptations with Endurance Training

• Increased capillary density and mitochondrial density.

VO2 Max and Speed Changes

• VO2 max improves with training. Speed improves, too, based on training intensity and other factors.

Muscle Growth, Hyperplasia, mTOR, and Satellite Cells

• Hyperplasia: Not occurring significantly in humans
• mTOR: Stimulated for protein synthesis, leading to muscle growth
• Satellite Cells: Muscle stem cells that contribute to muscle repair and growth.

High Intensity Interval Training (HIIT) Superiority

• Efficient training method – maximizing benefit in a shorter time.