B11 - Gass Exchange In Humans Flashcards
How does the lime water test tell you the difference between expired & inspired air
The lime water which gets expired air bubbled through it turns cloudy first showing us that expired air contains a higher quantity of carbon dioxide than inspired air
What is different about the amount of carbon dioxide, oxygen,& water vapour in inspired and expired air
Carbon dioxide - more in expired because it is used for respiration
Oxygen - more in inspired because it is needed for respiration
Water vapour - more in expired air as the water evaporates from the surface in the alveoli
What are the effects of physical activity on the rate and depth of breathing (loooong answer)
Both increase because
- when you exercise your muscles work harder
- to work harder they need more energy
- to get more energy they need to do more respiration
- to do more respiration they need more oxygen (and glucose)
- to get more oxygen they must take in more oxygen at the lungs by increasing the breathing rate and depth of breathing
- to get the oxygen (and glucose) to the respiring cells faster the heart must pump faster
What does the height of a wave from a spirometer tell you?
The depth of the breath that is taken
What are the features of the alveoli (gas exchange surface in humans)
- large surface area, the shape of the alveoli and the fact that there is so many of them makes a huge surface area
- thin wall, which is only one cell thick which makes a very short diffusion distance
- good blood supply as the blood is continuously moving which ensures that the concentration gradient is maintained
- good ventilation with air the body is constantly supplied with air as when you breathe new air with more oxygen is sent it
What are the effects of physical activity on the rate and depth of breathing (short answer)
An increased carbon dioxide concentration in the blood, which is detected by the brain, leading to an increased rate and greater depth of breathing
