5 The Respiratory System Free Online FlashCards

What four processes make up respiratory function?

The four linked processes are ventilation, gas exchange, gas transport, and control of breathing.

How does inhalation draw air into the lungs?

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

What causes air to flow out during quiet exhalation?

The breathing muscles relax, the lungs recoil, and pressure inside the lungs rises, pushing air out.

What is anatomical dead space?

Anatomical dead space is air remaining in the conducting airways that does not reach gas-exchanging surfaces.

What does alveolar ventilation measure?

Alveolar ventilation is the amount of fresh air reaching the alveoli each minute, making it more directly relevant to gas exchange than total air moved.

In which direction do respiratory gases diffuse?

Diffusion moves gases from regions of higher partial pressure to regions of lower partial pressure.

What happens during external respiration?

In the lungs, oxygen diffuses from alveolar air into the blood, while carbon dioxide diffuses from the blood into the alveoli. This is external respiration.

What happens during internal respiration?

At body tissues, oxygen diffuses from the blood into cells, while carbon dioxide diffuses from tissues into the blood. This is internal respiration.

What is pulmonary perfusion, and why does it matter?

Perfusion is blood flow through pulmonary capillaries. Effective exchange requires air and blood to reach compatible regions of the lung.

How is most oxygen transported in the blood?

Most oxygen travels attached to hemoglobin in red blood cells; only a small amount dissolves directly in plasma.

What conditions encourage hemoglobin to release oxygen in tissues?

Hemoglobin releases more oxygen in tissues where oxygen availability is lower, especially when carbon dioxide, acidity, and temperature are higher.

How do the medulla oblongata and pons contribute to breathing?

The medulla oblongata generates the basic breathing rhythm, while the pons helps adjust its timing and pattern.