Question

Indicate whether each statement is correct or incorrect as related to the diffusion of O_{2. correct or incorrect}

Diffusion rate is directly proportional to the pressure gradient between the alveolus and the pulmonary capillary

The a/A ratio evaluates the diffusion of oxygen between the alveolus and the systemic artery

Diffusion rate is inversely proportional to the surface area of the alveolar capillary membrane

Hypoventilation decreases the pressure gradient for diffusion of oxygen from the alveolus

Diffusion is limited by capillary transit time in normal lungs

Answer 1

Oxygen diffusion is a process occuring inside the body wher it moves from the place where there is a large concentration to where there is a lower concentration.Oxygen diffuses from the alveoli (where there is a higher concentration after an inspiration),into the blood inthe capillaries then to the tissues.

The movement of gas molecules from air into a liquid is directly proportional to the pressure gradient of gas.Here we can say the concentration gradient,that means the rate of diffusion is directly to the concentration gradient of the diffusing substance.In the alveolus after the inspiration the pressure gradient of oxygen in the alveolus is high than the capillaries.In the alveoli the concentration of oxygenis higher than the pulmonary capillary and here the pressure indicates that the partial pressure of oxygen or the measure of concentration of oxygen. So it starts diffusing from the alveolus to the capillary.

So the statement diffusion rate is directly proportional to the pressure gardient between the alveolus and the pulmonary capillary is correct.

a/A ratio is the ratio is the arterial alveolar oxygen tension ratio or the arterial oxygen partial pressure.It is used to predict the inspired oxygen concentration needed for a desired arterial oxygen tension.It is a test of the ability of oxygen to diffuse from the alveoli into the lungs or to the pulmonary capillaries.

So the statement "The a/A ratio evaluates the diffusion of oxygen between the alveolus and systemic artery" is correct.

In the diffusion of gas it is directly proportional to the available surface area of exchange and it is inversely proportional to the thickness of the membrane thickness.

So the statement "Diffusion rate is inversely proportional to the surface area of the alveolar capillary membrane" is incorrect

When the is abnormally slow in rate,the inspired amount of oxygen is less or partialpressure or the concentration gradient of the oxygen is below than normal resulting in an increased amount of carbon-di-oxide in blood is called as the hypoventilation.

So here the statement "Hypoventilation decreases the pressure gradient for diffusion of oxygen from the alveolus" is correct

The completeness of gas exchange depends on the time available and the oxygen and carbon-di-oxide tension gradients.it usually takes 0.75 seconds for a normal person.The body is maintaining a specific time for breathing Thus the body is maintaining a normal brathing pattern.

So here the statement "Diffusion is limited by capillary transit time in normal lung" is correct