Physical Education

• Cardiovascular system

  Made up of the heart, blood vessels, and blood
• Functions of the cardiovascular system


  • Transporting
  • Clotting
  • Temperature regulation
• Heart


  Pumps blood to the lungs and the rest of the body
• Heart


  • Four chambers - top two are atria, bottom two are ventricles
  • Left side deals with oxygenated blood, right side deals with deoxygenated blood
• Structures of the heart

  • Aorta
  • Left pulmonary artery
  • Left pulmonary veins
  • Left atrium
  • Semilunar valve
  • Bicuspid valve
  • Left ventricle
  • Interventricular septum
  • Superior vena cava
  • Right atrium
  • Tricuspid valve
  • Right ventricle
  • Inferior vena cava
  • Coronary artery
  • Left pulmonary vein
  • Left pulmonary artery
  • Coronary sinus
• Atria


  Small in diameter with thinner walls, push blood down to the ventricles
• Ventricles


  Have thicker walls, contract with greater force to push blood out of the heart
• Left side of the heart


  Larger than the right side, pumps blood around the body
• Right side of the heart

  Pumps deoxygenated blood to the lungs
• Blood flow through the heart

  1. Deoxygenated blood enters right atrium

  2. Passes through tricuspid valve to right ventricle

  3. Pumped through pulmonary artery to lungs

  4. Oxygenated blood returns to left atrium

  5. Passes through bicuspid valve to left ventricle

  6. Pumped through aorta to body
• Valves of the heart

  • Tricuspid valve
  • Bicuspid valve
  • Semilunar valves
• Blood vessels


  • Arteries
  • Veins
  • Capillaries
• Components of blood


  • Red blood cells
  • White blood cells
  • Platelets
• Red blood cells conduct oxygen, white blood cells fight infection, platelets help with clotting
• Cardiac cycle


  1. Medulla oblongata sends message along sympathetic nervous system

  2. Impulse hits SA node

  3. Impulse causes atria to contract

  4. Impulse reaches AV node

  5. AV node pauses

  6. Atria contract and ventricles fill

  7. AV node fires impulse down bundle of His

  8. Impulse causes ventricles to contract

  9. Left ventricle contracts more strongly
• Medulla oblongata


  Location of the cardiac control center
• SA node


  Sinoatrial node
• AV node


  Atrioventricular node
• Bundle of His


  Pathway for impulse to travel from AV node to ventricles
• Septum


  Structure that separates the heart into two
• The left ventricle has more cardiac muscle and contracts more strongly
• Engaging in physical activity regularly can improve cardiovascular health by strengthening the heart and improving circulation.
• Cardiac conduction system


  A group of specialized cells located in the wall of the heart which sends electrical impulses to the cardiac muscle causing it to contract
• How the heart beats


  1. Electrical impulse starts in the SA node

  2. Impulse spreads through the atria causing them to contract

  3. Impulse passes through the AV node

  4. Impulse passes down the bundle of His

  5. Impulse spreads through the Purkinje fibers causing the ventricles to contract
• Myogenic


  The capacity of the heart to generate its own impulses
• SA node


  A small mass of cardiac muscle found in the wall of the right atrium that generates the heartbeat, also known as the pacemaker
• AV node


  The node that relays the impulses between the upper and lower sections of the heart, delaying the transmission of the cardiac impulse for approximately 0.1 seconds to enable the atria to fully contract before ventricular systole begins
• Bundle of His


  A collection of heart muscle cells that transmit electrical impulses from the AV node to the ventricles
• Purkinje fibers


  Muscle fibers that conduct impulses in the wall of the ventricles
• Parts of the heart involved in the cardiac conduction system


  • Left atrium
  • AV node
  • Left ventricle
  • Purkinje fibers
  • Bundle branches
  • Right atrium
  • SA node
• How the impulse travels through the heart


  1. Starts in the SA node

  2. Causes the atria to contract

  3. Passes through the AV node

  4. Passes down the bundle of His

  5. Spreads through the Purkinje fibers

  6. Causes the ventricles to contract
• Factors affecting the rate of the cardiac conduction system


  • Sympathetic system (speeds up heart rate)
  • Parasympathetic system (decreases heart rate)
  • Medulla oblongata (controls heart rate)
• Sympathetic system


  Part of the autonomic nervous system that speeds up the heart rate
• Parasympathetic system


  Part of the autonomic nervous system that decreases the heart rate
• Medulla oblongata


  The most important part of the brain that regulates processes like breathing and heart rate
• Chemoreceptors


  Tiny structures in the carotid arteries and aortic arch that detect changes in blood acidity caused by the increase or decrease in the concentration of carbon dioxide
• Baroreceptors


  Special sensors in tissues in the aortic arch, carotid sinus, and pulmonary vessels that respond to changes in blood pressure to either increase or decrease the heart rate
• Proprioceptors


  Sensory nerve endings in the muscle, tendons, and joints that detect changes in muscle movements
• Chemoreceptors detect increased CO2


  Increases heart rate
• Baroreceptors detect increased blood pressure


  Decreases heart rate