respiration

• nasal passages

  trachea, bronchi and bronchioles carry gases to and from the lungs
• alveoli

  air sacs at the end of each bronchiole - they are the site of gas exchange ( O2 into blood, CO2 out of blood )
• ciliates epithelial cells

  1.air enters through nasal cavity

  2. air is warmed and filtered (in nasal cavity) before entering lungs

  3. ciliated epithelial cells line respiratory passage

  4. cilia on there surface along with mucus help to trap dirt and microbes which are removed by respiratory passage ( wafting motion of cilia)

  5. then swallowed and destroyed by digestive system
• pleural membranes

  1.line the inside of chest walls (ribs) and outside of the lungs

  2. reduce friction during breathing

  3. space between pleural membranes (pleural cavity) usually contains small amount of pleural fluid

  4. pleural fluid reduces friction during ventilation (breathing)
• intercostal muscles

  between each rib. they together with the diaphragm contract and relax to allow volume changes in the thorax