7 The Respiratory System Free Online FlashCards

Trace the path of air from the nose or mouth to the alveoli.

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

What are the main functions of the conducting zone?

The conducting zone moves air but does not exchange gases. It also warms, humidifies, and filters incoming air.

How do mucus and cilia help protect the respiratory tract?

Mucus traps particles, and cilia move the mucus toward the throat to be swallowed or expelled.

Where does gas exchange occur in the respiratory tract?

The respiratory zone includes respiratory bronchioles and alveoli; gas exchange occurs there.

How many lobes do the right and left lungs have?

The right lung has three lobes; the left has two, leaving room for the heart.

What are the roles of the visceral and parietal pleura?

The visceral pleura covers the lungs, while the parietal pleura lines the chest wall. Fluid between them reduces friction.

How are alveoli adapted for gas exchange?

Alveoli have thin walls next to pulmonary capillaries. Their large surface area and short diffusion distance support rapid gas exchange.

What changes cause air to enter the lungs during inhalation?

The diaphragm contracts and flattens, and external intercostals lift the ribs. The chest expands, lung pressure falls below atmospheric pressure, and air flows in.

How does quiet exhalation occur?

At rest, the diaphragm and external intercostals relax. Elastic recoil reduces lung volume, raises pressure, and pushes air out; this is usually passive.

What is anatomical dead space?

Anatomical dead space is air in the conducting passages that does not reach gas-exchanging surfaces. Therefore, alveolar ventilation is lower than total ventilation.

Which way do O₂ and CO₂ diffuse during external respiration?

In the lungs, O₂ diffuses from alveolar air into pulmonary blood, while CO₂ diffuses from blood into the alveoli. This is external respiration.

Which way do O₂ and CO₂ diffuse during internal respiration?

In body tissues, O₂ diffuses from blood into cells, while CO₂ diffuses from cells into blood. This is internal respiration.