MICROANATOMY

Detailed explanation-1: -Tiny air sacs at the end of the bronchioles (tiny branches of air tubes in the lungs). The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.

Detailed explanation-2: -The walls of the alveoli share a membrane with the capillaries. That’s how close they are. This lets oxygen and carbon dioxide diffuse, or move freely, between the respiratory system and the bloodstream. Oxygen molecules attach to red blood cells, which travel back to the heart.

Detailed explanation-3: -Bronchioles end in tiny air sacs called alveoli, where the exchange of oxygen and carbon dioxide actually takes place. Each person has hundreds of millions of alveoli in their lungs. This network of alveoli, bronchioles, and bronchi is known as the bronchial tree.

Detailed explanation-4: -Most bronchioles and large airways are part of the conducting zone of the lung, which delivers gas to sites of gas exchange in alveoli. Gas exchange occurs in the lungs between alveolar air and the blood of the pulmonary capillaries.

Detailed explanation-5: -Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. As shown below, inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli.