Unit 2 (CH:3)

• Respiration and breathing difference

  Respiration- oxidation reaction that releases energy from food such as glucose

  breathing- gas exchange
• Where are lungs?

  In chest or thorax
• where do lungs enclosed in?

  By ribcage or a muscular sheet of tissue called diaphragm
• How do you call two sets of muscles that join each rib next to each other?

  Intercostal muscles
• What are the shape of muscles and ribs that join together?

  Dome shape
• Bronchial tree meaning?

  The air passes of the lungs from a highly branching network.
• After passing air into nose and mouth, what do they pass to?

  Windpipe or trachea
• What does the trachea spilt into?

  Bronchi (singular bronchus)
• Bronchus divide into smaller tubes called..?

  Bronchioles
• Where do bronchioles end?

  At microscopic air sacs called alveoli (singular alveolus)
• What happens at alveoli?

  It is here that gas exchange with blood takes place.
• What do the walls of trachea and bronchi contain? And what do they do?

  They contain rings of gristle or cartilage. These support the airways and keep them open when they breathe in.
• Inside the thorax, what are lungs separated into?

  Two thin, moist membranes called pleural membranes.
• What do pleural membranes do?


  They make up a continuous envelop around the lungs, forming an airtight seal.
• What has between two membranes of space? What liquid is in there? What does it do?

  Pleural cavity.

  It has pleural fluid.

  It acts as a lubrication. The surfaces of the don’t stick to the side of the chest wall when we breathe in.
• How do cells in the trachea and large airways keep clean?

  -By secreting a sticky liquid called mucus.

  -some are covered with tiny hair-like structures called cilia.
• what does mucus do?

  Traps particles of dirt or bacteria that are breathed in.
• What does cilia do?

  Beat backwards and forwards, sweeping the mucus and trapped particles towards the mouth.
• Effects of smoking to cilia.

  Destroys cilia and stops this protection mechanism.
• Ventilation meaning

  it means moving air in and out of the lungs.
• Inhalation and exhalation differences 


  Inhalation: intercostal muscles relax (move your ribs upwards and outwards.)

  External intercostal muscles contract

  Diaphragm contracts

  Increases the volume of chest, slight drop pressure in thorax

  Than air outside

  Exhalation: opposite happens.

  
• How does being elastic help the lungs?

  They have a tendency to collapse and empty like a balloon.
• how is exhaled air different from atmospheric air?

  It is warmer and is saturated with water vapor.
• Two diseases related to lung

  Bronchitis

  Emphysema
• about bronchitis

  It has less cilia. Mucus isn’t swept away from lungs, block the airways.

  Smoke irritates, causes to secrete more mucus.

  Difficulty breathing properly.
• About emphysema

  Smoke damages wall of alveoli (break down and fuse again)

  forms enlarged, irregular air spaces.

  Carries less oxygen.
• How can carbon monoxide interfere breathing?


  Carbon monoxide enters the bloodstream.

  Attached to haemoglobin

  forms carboxyhaemoglobin , less oxygen carried.