This exchange allows easy diffusion of gasses back and forth.
They have capillaries close to their surfaces.
Each alveolar sac is surrounded by a network of capillaries that facilitate the exchange of gases (oxygen and carbon dioxide) between the air in the sac and the bloodstream. This close proximity allows for efficient gas exchange in the lungs.
The alveoli branch from the bronchioles and are responsible for gas exchange with the pulmonary capillaries. They come in close contanct with the capillaries so the exchange of O2 and Co2 can occur rapidly and easily.
The alveoli is the point where the waste product of respiration (carbon dioxide) and oxygen are diffused into or out of the blood. Oxygen diffuses into the blood stream and are carried to the heart and carbon dioxide is diffused out of the lungs and expired. The alveoli have moist walls and are close to the capillaries which speeds up the process.
A gas exchange (also called difusion) occurs between the alveoli of the lungs and the surrounding capillaries. The alveoli give oxygen into the bloodstream to be transported to the heart while the capillaries give the alveoli carbon dioxide to be removed from the body by exhalation (breathing out). Afterwards capillaries give nutrients and oxygen to all the cells of the body whilst taking out wastes to later be removed from the body. Hope this helped.
The pulmonary circulation works closely with the respiratory system at the alveoli. There, capillaries are in close proximity to the air sacs, and gases are exchanged at this point.
There is no anatomical connection of circulatory system with the respiratory system. Blood capillaries come in close contact with the lung alveoli. The area of contact is about 1000 square feet. But there are two thin membranes to separate blood and air. The walls of capillaries and the walls of alveoli. Both have flat and thin epithelium. The gases readily pass across these membranes.
Simple squamous epithelium is a flat single layered tissue that allows for diffusion to occur efficiently due to its thin structure and close arrangement of cells. It is found in areas where substances need to pass through easily, such as in the alveoli of the lungs where gas exchange occurs.
Gas is exchanged by diffusion. We have followed the path of the air and of the oxygen into the bloodstream. But breathing is a two-way street: we breathe in and then we breathe out. When we breathe in, or inhale, oxygen is removed from the air. Breathing also removes waste from the lungs and from our noses and mouths. How does this waste material get into the air that we breathe out, or exhale? The thin walls of the alveoli actually have two purposes. When we breathe in, oxygen passes through the walls of the alveoli and into the blood. Carbon dioxide and water vapor then travel the opposite direction. They are the main waste products that pass from the blood vessels (arteries) in the lungs, into the alveoli, through the windpipe and out the nose and mouth. In the alveoli, oxygen crosses over into the blood stream and carbon dioxide leaves the blood stream and enters the alveoli to be expelled through the lungs.
Diffusion of gases occurs in the alveolar region only because this is where the thin walls of the alveoli allow for efficient exchange of oxygen and carbon dioxide between the air in the lungs and the blood in the capillaries. The high surface area and close proximity of the alveoli to the capillaries facilitate rapid diffusion of gases.
There is no anatomical connection of circulatory system with the respiratory system. Blood capillaries come in close contact with the lung alveoli. The area of contact is about 1000 square feet. But there are two thin membranes to separate blood and air. The walls of capillaries and the walls of alveoli. Both have flat and thin epithelium. The gases readily pass across these membranes.
The blood passes through tiny capillaries that lie in close proximity to the alveoli in the lungs. This is where the gas exchange takes place.