AQA A Level PE Physiology Quiz

Introduction to AQA A Level PE Physiology

• AQA A Level Physical Education (PE) physiology explores the body's responses and adaptations to physical activity and exercise.
• Key concepts include energy systems, muscle physiology, cardiovascular responses, respiratory responses, and the endocrine system's role, including hormones.
• It also covers factors such as hydration, nutrition, and recovery.

Energy Systems

• The body uses three main energy systems to produce ATP (adenosine triphosphate), which is the energy currency of the cell.
  • ATP-PC System (Phosphagen System):
    • Provides rapid energy for short-duration, high-intensity activities like sprinting.
    • Utilizes stored phosphocreatine to rapidly regenerate ATP.
    • Limited capacity; quickly depleted.
  • Anaerobic Glycolysis:
    • Provides energy for short-term, high-intensity activities lasting up to 30-90 seconds (e.g., 400m run).
    • Breaks down glucose anaerobically (without oxygen), producing lactic acid as a byproduct.
    • Lower ATP yield compared to aerobic systems but faster production.
  • Aerobic Respiration:
    • The primary energy source for prolonged activities (e.g., marathon running, endurance training).
    • Breaks down glucose aerobically (with oxygen) in the mitochondria, producing a large amount of ATP.
    • Slow production of ATP, but sustained capacity.

Muscle Physiology

• Muscles are responsible for movement.
• Skeletal Muscle:
  • Composed of muscle fibers, which contain myofibrils (actin and myosin filaments).
  • Sliding filament theory describes how muscle contraction occurs.
• Muscle Fibre Types:
  • Fast-twitch (Type II) fibres are primarily used for quick, powerful movements and anaerobic activities.
  • Slow-twitch (Type I) fibres are more efficient and important for sustained, low-intensity aerobic activities.
• Muscle Fatigue:
  • Physiological inability to contract effectively.
  • Factors include depletion of energy stores, build-up of metabolic byproducts such as lactic acid, and nervous system fatigue.

Cardiovascular Responses

• The cardiovascular system transports oxygen and nutrients to muscles during exercise.
  • Heart Rate: Increases significantly with exercise to deliver more blood to working muscles.
  • Stroke Volume: The amount of blood pumped per beat by the heart; increases with exercise to improve oxygen delivery.
  • Cardiac Output: The amount of blood pumped per minute (heart rate x stroke volume); increases substantially during exercise.
  • Blood Pressure: Rises during exercise, with systolic pressure increasing more.
  • Blood Flow Redistribution: Blood flow is directed preferentially to working muscles, while blood flow is decreased to less active organs.

Respiratory Responses

• The respiratory system facilitates gas exchange to provide oxygen for aerobic energy production and remove carbon dioxide.
  • Ventilation Rate: Increases substantially during exercise to meet the body's increased oxygen demand.
  • Tidal Volume: The volume of air inhaled and exhaled per breath; increases during exercise.
  • Pulmonary Diffusion: The rate of gas exchange across the alveoli; increases with exercise to efficiently transport oxygen into the blood and expel carbon dioxide.

Endocrine System

• Hormones play a crucial role in regulating metabolic processes and responses to exercise.
  • Epinephrine (adrenaline) and norepinephrine increase heart rate, blood pressure, and blood flow, and enhance glucose mobilization.
  • Other hormones such as testosterone, growth hormone, and cortisol also have important roles in the adaptation to exercise.

Hydration and Nutrition

• Important for optimal performance and recovery.
  • Hydration maintains fluid balance, critical for thermoregulation and transporting nutrients.
  • Proper nutrition provides the necessary energy, nutrients, and fluids to support muscle function and recovery.

Recovery

• Refers to the body's processes which return it to a pre-exercise state.
  • Active recovery promotes blood flow to muscles and speeds up the removal of metabolic byproducts, aiding recovery.
  • Passive recovery allows the body to rest and recover.
  • Factors such as diet, sleep, and injury management influence recovery.