RESPIRATORY SYSTEM
BRONCHIOLE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
There is less oxygen in the alveoli and oxygen is going from highest concentration to lowest
|
|
|
There is less oxygen in the alveoli and oxygen is going from lowest concentration to highest
|
|
|
There is more oxygen in the alveoli and oxygen is travelling from lowest concentration to highest
|
|
|
There is more oxygen in the alveoli and oxygen is going from highest concentration to lowest
|
Detailed explanation-1: -The partial pressure of oxygen is high in the alveoli and low in the blood of the pulmonary capillaries. As a result, oxygen diffuses across the respiratory membrane from the alveoli into the blood. In contrast, the partial pressure of carbon dioxide is high in the pulmonary capillaries and low in the alveoli.
Detailed explanation-2: -a) The alveoli wall (and the capillary wall) is only one cell thick so there is only a short distance over which diffusion takes place (short diffusion pathway) so there is a faster rate of diffusion of oxygen from alveoli into the blood.
Detailed explanation-3: -During inspiration, the concentration of oxygen inside the alveoli is higher than that of blood capillaries whereas the concentration of carbon dioxide in blood capillaries is higher than that of alveoli.
Detailed explanation-4: -Partial pressures The alveolar oxygen partial pressure is lower than the atmospheric O2 partial pressure for two reasons. Firstly, as the air enters the lungs, it is humidified by the upper airway and thus the partial pressure of water vapour (47 mmHg) reduces the oxygen partial pressure to about 150 mmHg.
Detailed explanation-5: -Inside the air sacs, oxygen moves across paper-thin walls to tiny blood vessels called capillaries and into your blood. A protein called haemoglobin in the red blood cells then carries the oxygen around your body.