Latest CBSE Class 12 Physical Education Notes And Important Question Chapter 8 Physiology and Sports

December 21, 2024 ,

CBSE Physical Education Class 12 Notes Chapter 8 Physiology and Sports

CBSE Physical Education Class 12 Notes: Chapter 8 - Physiology and Sports

Introduction to Physiology in Sports

  • Physiology is the study of the functions and processes of the body and its systems.
  • In the context of sports, sports physiology focuses on how the body reacts to exercise and physical activity, and how these responses affect performance.
  • The chapter discusses the relationship between the body's physiological functions and athletic performance.

Key Concepts:

1. Understanding the Human Body's Systems:

  • The human body is made up of various systems like:
    • Cardiovascular system (Heart and blood vessels)
    • Respiratory system (Lungs)
    • Musculoskeletal system (Muscles and bones)
    • Nervous system (Brain and nerves)
    • Digestive system (Organs for food digestion)
    • Endocrine system (Hormones)

2. Physiological Responses to Exercise:

  • Cardiovascular system during exercise:

    • Heart rate increases to pump more oxygenated blood to muscles.
    • Stroke volume (amount of blood pumped per beat) increases.
    • Blood flow is diverted to working muscles.

  • Respiratory system during exercise:

    • Breathing rate increases to bring in more oxygen and expel carbon dioxide.
    • Tidal volume (volume of air per breath) increases.
    • Ventilation rate increases (amount of air moved in and out of the lungs per minute).

  • Musculoskeletal system during exercise:

    • Muscle fibers contract, leading to muscle shortening and movement.
    • Energy is provided to muscles from stored ATP (Adenosine Triphosphate).
    • Muscle fibers adapt to increase strength, endurance, and size with regular exercise.

  • Nervous system during exercise:

    • The central nervous system (CNS) controls the coordination of movements.
    • The peripheral nervous system transmits signals to muscles to initiate movement.

3. Energy Systems in the Body:

  • The body relies on three main energy systems during physical activity:

    • ATP-PC system (Phosphagen system):

      • Provides quick energy for short bursts (e.g., sprinting).
      • Uses creatine phosphate to regenerate ATP.
      • Active for 10-15 seconds.

    • Glycolytic system (Anaerobic system):

      • Provides energy for moderate-duration, high-intensity activities (e.g., 400-meter run).
      • Breaks down glucose without oxygen (anaerobic).
      • Results in the production of lactic acid (which can cause muscle fatigue).

    • Oxidative system (Aerobic system):

      • Provides energy for prolonged, low-intensity activities (e.g., long-distance running).
      • Uses oxygen to break down carbohydrates, fats, and proteins.
      • Produces carbon dioxide and water as byproducts.

4. Oxygen Debt:

  • Oxygen debt is the amount of oxygen needed to recover after exercise.
    • After intense exercise, the body needs extra oxygen to:
      • Replenish energy stores (ATP).
      • Remove lactic acid from the muscles.
      • Return the body to a resting state.

5. Fatigue and Recovery:

  • Fatigue occurs when the body’s energy reserves are depleted, and muscle function declines.
  • The two main types of fatigue:
    • Muscular fatigue: Caused by depletion of energy reserves (ATP) or accumulation of waste products (e.g., lactic acid).
    • Central fatigue: Occurs in the nervous system, affecting the brain’s ability to send signals to muscles.
  • Recovery involves replenishing energy stores, repairing muscle fibers, and removing metabolic byproducts.
    • Methods of recovery: Rest, hydration, nutrition, stretching, and cool-down exercises.

6. Adaptations to Exercise:

  • Regular physical activity leads to physiological adaptations that enhance performance:
    • Cardiovascular system adaptations: Increased heart size, stroke volume, and cardiac output.
    • Respiratory system adaptations: Increased lung capacity and more efficient oxygen utilization.
    • Musculoskeletal system adaptations: Increased muscle mass, strength, and endurance.
    • Endocrine system adaptations: Enhanced hormone regulation, which aids in muscle recovery and growth.

7. Training Principles:

  • To optimize performance, training programs should follow these principles:
    • Specificity: Training should focus on the specific skills or energy systems used in the sport.
    • Overload: Gradually increasing the intensity or duration of exercise to improve performance.
    • Progression: Continually increasing the intensity, duration, or frequency of exercise to avoid plateauing.
    • Reversibility: If training stops, the body will lose adaptations over time.
    • Variation: Introducing variety in exercises to avoid monotony and prevent injuries.

8. Sports Nutrition:

  • Nutrition plays a key role in maintaining energy levels and supporting recovery.
    • Carbohydrates: Primary energy source during exercise.
    • Proteins: Essential for muscle repair and growth.
    • Fats: Source of energy for prolonged activities.
    • Hydration: Proper fluid intake is necessary to avoid dehydration during physical activities.

9. Hormonal Responses to Exercise:

  • Exercise stimulates the release of hormones that impact performance:
    • Adrenaline: Increases heart rate, blood flow, and energy production.
    • Cortisol: Released during stress and exercise to aid in energy mobilization.
    • Growth hormone: Stimulates muscle growth and repair.
    • Testosterone: Increases muscle mass and strength.
    • Endorphins: Help reduce pain and improve mood.

Conclusion:

  • Understanding physiology is crucial for athletes to optimize their performance and recovery.
  • Sports physiology explains the relationship between exercise and bodily functions and emphasizes the importance of proper training, nutrition, and recovery for maximizing performance.

These notes provide a concise overview of Chapter 8: Physiology and Sports in CBSE Physical Education Class 12. To excel in exams, it's essential to grasp the physiological responses to exercise and their impact on athletic performance.


CBSE NCERT Physical Education Class 12 Important Questions Chapter 8 Physiology and Sports

Here are some important questions from Chapter 8: Physiology and Sports for CBSE Physical Education Class 12, based on the NCERT syllabus:

Important Questions:

Short Answer Questions (2-3 Marks):

  1. What is sports physiology? Explain its importance in sports performance.

    • Answer: Sports physiology is the study of how the body reacts and adapts to physical activity and exercise. It helps in understanding how different systems in the body—such as the cardiovascular, respiratory, and musculoskeletal systems—function during physical exertion. This knowledge aids in optimizing training, enhancing performance, and preventing injuries.

  2. Explain the role of the cardiovascular system during exercise.

    • Answer: During exercise, the heart pumps more blood to the muscles, increasing the oxygen supply for energy production. The stroke volume (amount of blood pumped per beat) and heart rate increase to meet the body's demand for oxygen. The vascular resistance decreases, allowing for better blood flow to the working muscles.

  3. What is oxygen debt?

    • Answer: Oxygen debt refers to the amount of oxygen required to restore the body to its normal state after intense physical activity. This involves replenishing energy stores (ATP), removing lactic acid buildup, and normalizing heart rate and breathing.

  4. Discuss the effects of exercise on the respiratory system.

    • Answer: During exercise, the breathing rate and tidal volume (the amount of air taken in with each breath) increase. This is done to bring in more oxygen and expel carbon dioxide. The efficiency of the lungs increases, enhancing the body's ability to perform prolonged physical activities.

  5. What is the difference between aerobic and anaerobic exercise?

    • Answer: Aerobic exercise is a moderate-intensity activity that relies on oxygen for energy production (e.g., running, and swimming). It enhances cardiovascular and muscular endurance. Anaerobic exercise involves short bursts of high-intensity activity that don’t require oxygen for energy production (e.g., sprinting, weightlifting). It builds strength and power.

Long Answer Questions (5 Marks):

  1. Explain the three energy systems in the body used during physical activity.

    • Answer: The body uses three energy systems during exercise:
      • ATP-PC System (Phosphagen System): Provides immediate energy for short bursts of activity (0-10 seconds), using stored ATP and creatine phosphate.
      • Glycolytic System (Anaerobic System): Provides energy for activities lasting up to 2 minutes, using glucose in the absence of oxygen, producing lactic acid as a byproduct.
      • Oxidative System (Aerobic System): Provides energy for prolonged activities, using oxygen to break down carbohydrates, fats, and proteins to produce ATP.

  2. Discuss the physiological changes that occur during exercise.

    • Answer:
      • Cardiovascular System: Heart rate and stroke volume increase, resulting in greater cardiac output. Blood is diverted to working muscles.
      • Respiratory System: Breathing rate and tidal volume increase to supply more oxygen to muscles and remove carbon dioxide.
      • Musculoskeletal System: Muscle fibers contract, leading to movement, and energy (ATP) is used to facilitate muscle contraction.
      • Nervous System: The brain sends signals to the muscles for coordination, initiating and controlling movements.
      • Metabolic Changes: The body shifts from anaerobic to aerobic metabolism based on the intensity and duration of exercise.

  3. Explain the concept of fatigue and its types.

    • Answer:
      • Fatigue is a state of physical and mental exhaustion that hinders an individual's ability to perform optimally.
      • Muscular Fatigue: Occurs when muscle energy stores (ATP and glycogen) are depleted, or when lactic acid accumulates, causing discomfort and reducing muscle function.
      • Central Fatigue: Results from a decrease in the central nervous system’s ability to send signals to muscles, often due to prolonged exertion.
      • Psychological Fatigue: Caused by mental stress or lack of motivation, affecting an athlete's focus and performance.

  4. Describe the role of hormones in regulating physical performance.

    • Answer: Hormones play a critical role in regulating energy production, muscle growth, and recovery:
      • Adrenaline (Epinephrine): Increases heart rate, blood flow to muscles, and the release of glucose for quick energy during exercise.
      • Cortisol: Released in response to stress, it helps in energy mobilization, but prolonged release can lead to muscle breakdown.
      • Growth Hormone: Stimulates muscle growth and repair during exercise and recovery.
      • Insulin: Regulates glucose uptake by cells, ensuring energy is available for muscle contraction.
      • Endorphins: Help reduce pain and stress during prolonged exercise, creating a sense of well-being.

Very Short Answer Questions (1 Mark):

  1. What is the main source of energy during high-intensity exercise?

    • Answer: The main source of energy during high-intensity exercise is the ATP-PC system (Phosphagen system), which uses stored ATP and creatine phosphate.

  2. What is lactic acid and how does it affect muscles?

    • Answer: Lactic acid is a byproduct of anaerobic energy production. It accumulates in muscles, causing fatigue and discomfort, which limits performance.

  3. Name the two types of fatigue caused by exercise.

    • Answer: The two types of fatigue are muscular fatigue and central fatigue.

  4. What is the primary function of the respiratory system during exercise?

    • Answer: The primary function of the respiratory system during exercise is to increase oxygen intake and expel carbon dioxide to meet the demands of the body’s working muscles.

  5. Which energy system is used during long-distance running?

    • Answer: The oxidative system (aerobic system) is used during long-distance running.

These important questions cover a range of topics from Chapter 8: Physiology and Sports in CBSE Physical Education Class 12 and will help you in exam preparation. Understanding the physiological aspects of sports will improve your knowledge of the body's responses and adaptations to exercise.


Physical Education Class 12 Notes And Important Questions CBSE


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