Alveoli
Because they are the lining of the lungs that begin the process of taking oxygen out of the air and into the blood stream. They are the parts that actually coe into contact with the "air" and are therefore called the functional part of the lungs.
Alveoli are the smallest functional units of the lungs. Therefore, they belong to the respiratory system.
The alveoli (singular, alveolus) are the functional units of the lungs of mammals.
The alveoli (singular, alveolus) are the functional units of the lungs of mammals.
The alveoli (singular, alveolus) are the functional units of the lungs of mammals.
They are genes.
Actually, the structure of the lunge is make up Visceral pleura, Parietal pleura, and Pleural cavity
Nephron units are located in the kidney cortex. They are the functional units responsible for filtering blood and regulating the electrolyte balance and fluid volume in the body. Each kidney contains thousands of nephron units.
Genes are the functional units of heredity.
alveoli
Reptiles have lungs as their primary breathing organs. They rely on the expansion and contraction of their rib cage to facilitate breathing, drawing oxygen into their lungs and expelling carbon dioxide. Some reptiles, like snakes, have a single functional lung, while others have two functional lungs.
One of the functional units of a myofibril is the sarcomere. The word sarcomere comes from the Greek words sarx, meaning flesh, and meros, meaning part.