Gas Exchange

• What is the definition of Countercurrent Flow?

  flow of water over fill lamellae and flow of blood within them are in opposite direction
• What does a Countercurrent flow allow in an insect?

  diffusion gradient maintained all the way across gill lamellae
• What are the tiny pores on an insect called?

  spiracles
• What are the two features of Tracheoles in an insect?

  . thin walls,

  . highly branched,
• How does these two features of an insects Tracheoles increase diffusion?

  . shorten diffusion pathway,

  . increases surface area,
• What is an adaptation of Spiracles within an insect?

  close/ not open all the time
• How does the adaptation of Spiracles in an insect increase diffusion?

  prevents water loss - keep organism water proof
• How does a Countercurrent Flow work?

  . water and blood flow in opposite directions,

  . blood has a higher oxygen concentration,

  . diffusion happens along full length of lamellae,

  . blood absorbs more oxygen,

  . has concentration gradient, more O2 can flow into the blood,
• What is the adaptation of lamellae in fish?

  thin epithelium/walls
• How does a large number of Capillaries around Lamellae increase Diffusion?

  good blood supply maintains concentration gradient via constant removal of oxygenated blood
• How does having ventilation by operculum in a fish increase the rate of Diffusion?

  ensures constant fresh water flow over gills to replace lost oxygen and maintains concentration gradient
• What is the pathway of air in a human?

  trachea & bronchi & bronchioles & alveoli
• How does Alveolar Epithelium & Capillary Endothelium being thin increase diffusion?

  shorten diffusion pathway
• How does having a large number of Alveoli in a human increase Diffusion?

  increase surface area
• How does having Capillaries surround the Alveoli increase the Diffusion?

  increasing the time for diffusion
• How does having a large number of Capillaries around the Alveoli increase Diffusion?

  maintains a steep concentration gradient
• How does having a Constant Ventilation of air increase Diffusion?

  maintains a steep concentration gradient
• What is the first step of Inhalation?

  diaphragm contracts
• What is the second step of Inhalation?

  external intercostal muscles contract pulling ribcage moves up and out
• What is the third step of Inhalation?

  increases volume of thoracic cavity which reduces air pressure because there is more space
• What is the fourth step of Inhalation?

  air moves into trachea down the pressure gradient (high to low)
• Does Inhalation need energy?

  requires energy
• What is the first step of Exhalation?

  diaphragm relaxes
• What is the second step of Exhalation?

  external intercostal muscles relax, ribcage moves in and down
• What is the third step of Exhalation?

  decreases volume of thoracic cavity increase air pressure because there is less space
• What is the fourth step of Exhalation?

  air moves out of the trachea down pressure gradient
• Is Exhalation an active process?

  passive process
• What are two types of lung diseases?

  restrictive diseases & obstructive diseases
• What is the definition of Forced Expiratory Volume (FEV1)?

  maximum volume of air that can be breathed out in 1 second
• What is the definition of Forced Vital Capacity (FVC)?

  maximum volume of air that is possible to breathe forcefully out of lungs
• What is the definition of Restrictive disease?

  difficult to fully breathe in & severely reduces FVC as breathing in is difficult & FEV less affected because breathing out is normal
• What is the definition of Obstructive diseases?

  difficult to breathe out as airways as blocked & FVC and FEV are both much lower than normal
• What is the equation for gas exchange?

  pulmonary ventilation (dm3min-1) = tidal volume (dm3) X breathing rate (min-1)
• What is an adaptation of wax in plant cells?

  prevents evaporation & prevents water loss
• What is the equation for Respiration?

  C6H12O6 + 6O2 --> Energy + 6CO2 + 6H2O
• What does Respiration require?

  oxygen
• How long does Respiration take place?

  24 hours a day
• What is the equation for Photosynthesis?

  6CO2 + 6H2O --> C6H12O6 + 6O2
• What does Photosynthesis require?

  carbon dioxide
• What is the definition of Flaccid?

  water leaves