Question

Name the structural and functional unit of lungs.How is it designed to maximize the exchange of gases (3 points)

Answer 1

Answer:

Lungs play a major role in the respiratory system. In humans, a pair of lungs are designed in such a way that they are lined by a thin membrane, the smaller tubes called bronchioles a balloon-like structure called alveoli and network of blood capillaries increase the surface area for exchange of gases.

Humans have two lungs and are situated within the thoracic cavity of the chest. They are soft spongy and elastic organ enclosed in a thin membranous sac called the pleura. Lungs are divided into a smaller structure called bronchi which are divided into bronchioles. Alveoli are small, round or balloon-like structure found the end of the bronchioles and provide a larger surface area and maximizes the exchange of gases inside the lungs.

Answer 2

Alveoli is the structural and functional unit of lungs .

Within the lungs , the air passage

divides into smaller and smaller tubes

called bronchi which in turn form

bronchioles . The bronchioles terminate

in balloon-like structures called alveoli .

The alveoli present in the lungs provide

maximum surface for exchange of gases .

The alveoli have vary thin walls and

contain an extensive network of blood

vessels to facilitate exchange of gases .