What causes oxygen to diffuse into the blood from the alveoli?

Answer 1

Oxygen is, of course, a gas our bodies are dependent on and need for us function properly. However, our body doesn't produce oxygen yet it is present in our external environment (in the air). So our body has specific structures and systems in place to function to extract this gas from the environment so we can use it. We breath in oxygen and it enters the alveoli in our lungs which are like tiny air sacs. These sacs are covered by a thin film of moisture and are also in close proximity to a complex network of blood cappilaries. Substances move accross membranes through diffusion which is due to a difference in concentrations of that substance on both sides of the membrane. The movement occurs from places of high concentration to places of lower concentration, down the concentration gradient, thus, it is a passive process. The blood that has pumped around our body has been depleted of oxygen as our body cells have taken it up which leaves the blood that comes to the alveoli deoxygenated and low in concentration of oxygen (however it is is high in concentration of CO2 which is a waste product of cellular respiration). When we breathe in, the air that enters are lung is full of oxygen (infact about 20.95%) thus we can say that there is higher concentration of o2 in the alveoli than there is in the blood. This triggers diffusion to occur from the alveoli to the blood hence we can say that differences in concentration causes it diffuse over. The gas has to pass through that thin film of moisture which is essential as gases can only be exchanged in a dissolved form. hope this helps, email mitchcook@live.com for further explanation

Answer 2

Oxygen is, of course, a gas our bodies are dependent on and need for us function properly. However, our body doesn't produce oxygen yet it is present in our external environment (in the air). So our body has specific structures and systems in place to function to extract this gas from the environment so we can use it. We breath in oxygen and it enters the alveoli in our lungs which are like tiny air sacs. These sacs are covered by a thin film of moisture and are also in close proximity to a complex network of blood cappilaries. Substances move accross membranes through diffusion which is due to a difference in concentrations of that substance on both sides of the membrane. The movement occurs from places of high concentration to places of lower concentration, down the concentration gradient, thus, it is a passive process. The blood that has pumped around our body has been depleted of oxygen as our body cells have taken it up which leaves the blood that comes to the alveoli deoxygenated and low in concentration of oxygen (however it is is high in concentration of CO2 which is a waste product of cellular respiration). When we breathe in, the air that enters are lung is full of oxygen (infact about 20.95%) thus we can say that there is higher concentration of o2 in the alveoli than there is in the blood. This triggers diffusion to occur from the alveoli to the blood hence we can say that differences in concentration causes it diffuse over. The gas has to pass through that thin film of moisture which is essential as gases can only be exchanged in a dissolved form. hope this helps, email mitchcook@live.com for further explanation