The Lungs and the Heart

• What is the function of the trachea?

  It conducts air to and from the lungs
• What is the primary function of the lungs?

  Gas exchange
• How do gases diffuse in the lungs?

  Between the alveolus and the blood
• What surrounds the alveoli?

  A capillary network
• What type of blood does the pulmonary artery carry?

  Deoxygenated blood
• What type of blood does the pulmonary vein carry?

  Oxygenated blood
• What are the two circuits in the human circulatory system?

  Heart to lungs and heart to body
• What is the role of the pacemaker cells?

  They control resting heart rate
• What happens if the natural pacemaker cells fail?

  An artificial pacemaker can control heartbeat
• What do coronary arteries supply to the heart muscle?

  Oxygenated blood
• What are the components of the circulatory system?

  • Heart (pumping organ)
  • Blood vessels
  • Blood
• Describe the double circulatory system in humans.

  • Two circuits:

  1. Heart to lungs (pulmonary circuit)
  2. Heart to rest of body (systemic circuit)
• What is the significance of valves in the heart?

  • Prevent blood from flowing backwards
• What is the role of the aorta?

  • Carries oxygenated blood to the body
• What is the role of the vena cava?

  • Carries deoxygenated blood from the body