Gas exchange of oxygen and carbon dioxide takes place in the alveoli. Oxygen from the inhaled air diffuses through the walls of the alveoli and adjacent capillaries into the red blood cells. The oxygen is then carried by the blood to the body tissues. Alveoli have a lot of tiny blood vessels called capillaries.

Human Respiratory System comprises organs responsible for respiration. Nose, mouth, pharynx, larynx, trachea, bronchi, lungs. Explore more about respiratory system parts and functions only at BYJU'S

Partial pressure: Alveoli are tiny air sacs in the shape of a balloon. During the act of breathing in and out, the alveoli are where the lungs and blood exchange oxygen and carbon dioxide. The pressure exerted by oxygen in a mixture in the alveoli of lungs is known as the partial pressure of oxygen. It is represented by pO 2. Alveoli have a pO2 of 104 mm Hg.

The alveoli is the location of gaseous exchange between the respiratory system and blood capillaries. From the hilum, the lymphatic vessels, nerves, bronchus, and pulmonary arteries and veins enter the lungs.

The second reason is because the alveoli walls are only one cell thick, meaning the oxygen only has two cells to go through, the alveoli wall, and the capillary wall. They are tiny pockets in the lungs at the end of the bronchioles, where oxygen diffuses into the blood and carbon dioxide diffuses out of the blood. .

Alveoli Each bronchiole ends in spongy, tiny sacs – alveoli; each of the individual sacs is referred to as alveolus. Each alveolus fills with air when a person inhales. Together, the bronchi, bronchioles and alveoli constitute the bronchial tree. The alveoli are surrounded by tiny blood vessels referred to as capillaries.

The alveoli are thin-walled and richly supplied with a network of blood vessels to facilitate the exchange of gases between blood in the capillaries and the air inside the alveoli. These alveoli are balloon-like structures which provide the maximum surface area for the exchange of gases.

Also, they aid the bronchioles during the inspiration and expiration process. Each terminal bronchiole further divides into respiratory bronchioles. Respiratory Bronchioles The respiratory zone consists of the respiratory bronchioles, alveoli and alveolar ducts. It is the main site for the exchange of O 2 and CO 2 with the blood.

Respiration is a biological process involved in the production of energy. During this process,the exchange of gases occurs between the external environment and the tissues.

Type 1 and type 2 cells are two kinds of alveolar cells. These cells differ both structurally and functionally. While type 1 cells help in gaseous exchange, type 2 cells secrete surfactant proteins that reduce alveolar surface tension. Learn many such differences between type 1 and type 2 pneumocytes, only at BYJU’S.