DENDROLOGY

Detailed explanation-1: -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-2: -Diffusion is the spontaneous movement of gases, without the use of any energy or effort by the body, between the alveoli and the capillaries in the lungs. Perfusion is the process by which the cardiovascular system pumps blood throughout the lungs.

Detailed explanation-3: -At the end of each bronchiole is a cluster of little air sacs called alveoli. Alveoli are wrapped in tiny blood vessels called capillaries. The air you breathe in fills these air sacs with oxygen-rich air. This is where the exchange of gases occurs.

Detailed explanation-4: -Gas exchange is the physical process by which gases move passively, meaning that no energy is required to power the transport, by diffusion across a surface.

Detailed explanation-5: -Gas exchange takes place by active transport because oxygen and carbon dioxide move down their concentration gradients from a region of high to low concentration.