Respiration

• What is the primary function of the heart?

  Pumping blood
• Which blood vessels carry oxygenated blood away from the heart?

  Arteries
• What is the name of the largest artery in the human body?

  Aorta
• In which chamber of the heart does oxygenated blood enter from the lungs?

  Left atrium
• What is the purpose of valves in the heart?

  To prevent the backflow of blood
• Which component of blood is responsible for carrying oxygen to the body tissues?

  Red blood cells
• What causes the lub-dub sound of the heartbeat?

  Closing of heart valves
• What is the purpose of the coronary arteries?

  To supply the heart muscle with oxygen and nutrients
• What is the term for the circulation of blood from the heart to the lungs and back?

  Pulmonary circulation
• What is the average resting heart rate for a healthy adult?

  60-100 beats per minute
• What is breathing (ventilation)?

  The movement of gases into and out of the gas exchange system
• What is gas exchange?

  The exchange of gases across the gas exchange surface between the air and the body
• Does respiration mean to breathe?

  False
• Do plants and animals have gas exchange systems?

  True
• What is the function of the lungs?

  To enable gas exchange to take place
• What happens to oxygen and carbon dioxide during gas exchange?

  Oxygen enters and carbon dioxide leaves
• How are plant leaves adapted for gas exchange?

  They are thin enough for carbon dioxide to diffuse straight into them
• What are the steps involved during inhalation?

  1. Intercostal muscles contract, moving the ribs up and out
  2. Diaphragm contracts and flattens
  3. Increases the volume of thorax
  4. Decrease in pressure in thorax
  5. Higher pressure outside causes air to rush in
• What are the steps involved during exhalation?

  1. Intercostal muscles relax, moving the ribs down and in
  2. Diaphragm relaxes and curves
  3. Decreases the volume of thorax
  4. Increases in pressure in thorax
  5. Higher pressure inside causes air to rush out
• How are the lungs adapted for efficient gas exchange?

  • Numerous capillaries
  • Thin-walled alveoli
  • Large surface area
• Why are fish gills similar to alveoli?

  They have a large surface area, thin walls, and a close capillary system
• How do alveoli facilitate gas exchange?

  They provide a large surface area and a short diffusion pathway
• What is the significance of maintaining a concentration gradient in gas exchange?

  It allows for efficient diffusion of gases
• What is the passage of oxygen through the respiratory system?

  Mouth/Nose → Trachea → Bronchus → Bronchioles → Alveoli → Capillaries → Heart → Body
• What happens to breathing during exercise?

  Breathing rate increases to supply more oxygen to the body
• What are the adaptations of the alveoli for gas exchange?

  They have many alveoli, a large surface area, thin walls, and a good blood supply
• How do gill filaments in fish contribute to gas exchange?

  They provide a large surface area and maintain a concentration gradient