Content

• What is the function of the larynx?


  It forms an air passage to the lungs connecting the back of the nose and trachea.
• Where does gas exchange take place in the respiratory system?


  In the alveoli.
• What role does the diaphragm play in breathing?


  It separates the chest from the abdomen and controls breathing by contracting and relaxing.
• What is the primary function of the trachea?


  It allows the passage of air in and out of the lungs.
• What do the bronchi do?


  They carry air to and from the lungs.
• What is the function of bronchioles?


  They carry air to small sacs called alveoli.
• How does the larynx protect the respiratory system?


  It prevents food from entering the wrong windpipe.
• What is the role of the pharynx in the body?


  It supports both the digestive and respiratory systems.
• What is the function of the nasal/mouth cavity?


  It warms, filters, and moistens air before it enters the lungs.
• What is the role of the external intercostal muscles during inhalation?


  To draw air into the lungs
• How does the contraction of the external intercostal muscles affect the ribcage?


  It causes the ribcage to swing up and out
• What happens to the diaphragm during inhalation?


  Nerve impulses make it contract and flatten
• What is the effect of the diaphragm pressing on digestive organs during inhalation?


  It helps create negative pressure in the lungs
• Why do the lungs stretch during inhalation?

  Because pleural membranes are attached to the ribcage and diaphragm
• What happens to the internal volume of the lungs during inhalation?


  It increases, causing air pressure to decrease
• What is the result of the pressure in the lungs decreasing below atmospheric pressure?


  Air rushes into the lungs, inflating the alveoli
• What is the primary role of the diaphragm during expiration?


  To carry out expiration
• What happens when the brain stops sending nerve messages to the diaphragm?


  The diaphragm stops contracting and springs back to its domed position
• How does gravity affect the ribcage during expiration?


  It causes the ribcage to drop back and downwards
• What happens to air pressure in the lungs during expiration?


  It increases above atmospheric pressure
• What role do internal intercostal muscles play during forceful expiration, such as coughing?


  They contract to pull the ribcage back down with more force
• What is the function of pleural membranes in the respiratory system?


  They are crucial for lungs inflating and deflating
• How do pleural membranes prevent friction?


  They allow smooth movement as the lungs expand and contract
• What happens if the space between the pleural membranes is punctured?


  The lung on that side will not inflate
• What are the adaptations of alveoli for gaseous exchange?


  • Very large surface area for diffusion
  • One cell thick for minimal diffusion distance
  • Lots of blood capillaries for good blood supply
  • Moist surfaces for gas dissolution
• What is the primary function of alveoli?


  To serve as the site of gaseous exchange
• What occurs during the gaseous exchange in alveoli?


  Oxygen enters the blood and carbon dioxide is removed
• Why do alveoli have a large number of air sacs surrounded by capillaries?


  To provide a large surface area for gas exchange
• How thick are the walls of alveoli and capillaries?


  They are very thin, one flattened cell thick
• What is the purpose of the thin layer of water on the inner surfaces of alveoli?


  To allow oxygen to dissolve before passing through
• What is the diffusion gradient in the context of gaseous exchange?


  It refers to the concentration differences of gases between alveoli and blood
• Why does oxygen diffuse into the blood from the alveoli?


  Because there is a higher concentration of oxygen in inhaled air than in blood
• What happens to oxygen after it diffuses into the blood?


  It combines with hemoglobin in erythrocytes to form oxyhemoglobin
• In which direction does carbon dioxide diffuse during gaseous exchange?


  From the blood into the alveoli
• How does the concentration of carbon dioxide in exhaled air compare to inhaled air?


  Exhaled air has higher levels of carbon dioxide
• What is the role of erythrocytes in the respiratory system?


  To transport oxygen via hemoglobin to body tissues
• What is the role of plasma in the respiratory system?


  To transport carbon dioxide produced by respiration to the lungs
• What are the main steps in the process of respiration?


  1. Inspiration (breathing in)
  2. Exchange of gases from lungs to blood
  3. Transport of oxygen and carbon dioxide in the blood
  4. Exchanges of gases from blood to tissues
  5. Metabolism
  6. Expiration