10 The Respiratory System Free Online FlashCards

What are the respiratory system’s main functions?

It brings oxygen into the body and removes carbon dioxide produced by cells.

How does air travel from the entrance of the respiratory system to the alveoli?

Air passes from the nose or mouth through the throat and larynx, trachea, bronchi, and bronchioles to the alveoli.

What does the nose do to incoming air?

The nose helps warm and moisten incoming air.

What does the diaphragm do during inhalation?

It contracts and moves downward, expanding the chest cavity and drawing air into the lungs.

What happens when the diaphragm relaxes during breathing?

The diaphragm relaxes, the chest cavity becomes smaller, and air flows out of the lungs.

What makes alveoli effective sites for gas exchange?

Alveoli are tiny air sacs surrounded by capillaries. Their thin walls allow gases to diffuse between alveolar air and blood; this exchange is external respiration.

Why does oxygen diffuse from alveoli into the blood?

Oxygen diffuses from alveolar air into the blood because its concentration is higher in the alveoli than in the incoming blood.

Which way does carbon dioxide move during gas exchange in the lungs?

Carbon dioxide diffuses from the blood into the alveoli and is then exhaled.

How is most oxygen transported in the blood?

Most oxygen travels through the bloodstream attached to hemoglobin, a protein in red blood cells.

What happens during internal respiration?

Oxygen moves from the blood into body cells, while carbon dioxide produced by cells enters the blood. This exchange is internal respiration.

How is much of the body’s carbon dioxide carried to the lungs?

Much of it travels in the blood as bicarbonate, which is converted back into carbon dioxide in the lungs and exhaled.

Where do pulmonary arteries carry blood?

They carry blood from the heart toward the lungs, to capillaries around the alveoli.