Question

Identify the factors essential to successful ventilation, perfusion, and diffusion. Discuss how oxygen and carbon dioxide are transported to and from the lungs and capillaries. Also discuss factors affecting the diffusion of these substances across the alveolar membrane.

Answer 1

The factors essential for gas exchange are ;

-presure gradient of the gases

-Solubility of the gases

-Membrane thickness ( if it is thick , takes more time for gas exchange)

GAS EXCHANGE

The air enters into the body through nose or mouth and quickly moves to the pharynx or throat from their air passes into larynx or voice box . Then it passes into the trachea, the trachea is a strong tube that contains rings and cartilages which prevents collapsing. Trachea is divided into left and right bronchus again it is divided into smaller smaller branches called bronchioles.These bronchioles has small air sac structures called alveoli.gas exchange is the delivery of oxygen from lungs to blood stream and elimination of carbon dioxide from blood stream to the lungs . There is tiny blood vessels within the walls of alveoli called capillaries.. Here the red blood cells travel through the capillaries . Oxygen and carbon dioxide diffuse between alveoli and capillaries . This makes them to move freely between the respiratory system and the blood stream . Oxygen molecules attach to the red blood cells and travel back to the heart . At the same time carbon dioxide in the alveoli is eliminated during exhalation.