MRCP UK EXAMINATIONS

Detailed explanation-1: -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.

Detailed explanation-2: -Within the lungs, the bronchi branch into smaller bronchi and even smaller tubes called bronchioles (pronounced: BRAHN-kee-olz). Bronchioles end in tiny air sacs called alveoli, where the exchange of oxygen and carbon dioxide actually takes place.

Detailed explanation-3: -Oxygen breathed in from the air passes through the alveoli and into the blood and travels to the tissues throughout the body. Carbon dioxide travels in the blood from the body’s tissues and passes through the alveoli to be breathed out.

Detailed explanation-4: -Blood passes through the capillaries, entering through your PULMONARY ARTERY and leaving via your PULMONARY VEIN. While in the capillaries, blood gives off carbon dioxide through the capillary wall into the alveoli and takes up oxygen from air in the alveoli.

Detailed explanation-5: -Lungs contain specialised structures called alveoli which are the site of exchange of oxygen and carbon dioxide between the blood and air. Hence, the alveoli are responsible for absorption of oxygen into the blood.