How the lungs exchange gases

What are alveoli?

Tiny air sacs in the lungs where gas exchange occurs.

Function of the diaphragm?

Muscle that separates thoracic and abdominal cavities; aids in breathing.

True or false: Lungs use passive diffusion.

True, because gases move from high to low concentration.

Difference between oxygen and carbon dioxide exchange.

Oxygen enters blood from alveoli; carbon dioxide exits blood into alveoli.

Fill in the blank: The process of breathing is called ___.

ventilation.

What drives the breathing process?

Differences in air pressure between the lungs and the atmosphere.

True or false: Gas exchange only occurs during inhalation.

False, because it occurs continuously during breathing.

Role of hemoglobin in gas exchange?

Transports oxygen from lungs to cells and carbon dioxide back to lungs.

What is partial pressure?

Pressure exerted by a single gas in a mixture; crucial in gas exchange.

Describe the role of surfactant.

Reduces surface tension in alveoli, preventing collapse.

What happens during exhalation?

Diaphragm relaxes, lung volume decreases, air is pushed out.

What is the primary gas exchanged in the lungs?

Oxygen is primarily absorbed; carbon dioxide is expelled.

True or false: All cells in the body use oxygen.

True, because cellular respiration requires oxygen for energy.

How does air move into the lungs?

Air moves in through negative pressure created by diaphragm contraction.

What is ventilation?

The process of moving air into and out of the lungs.

Difference between external and internal respiration.

External: gas exchange in lungs; Internal: exchange in tissues.

What is the respiratory membrane?

Thin barrier where gas exchange occurs between alveoli and blood.

Fill in the blank: The total amount of air a lung can hold is called ___.

lung capacity.

Question: Why is oxygen important?

It is needed for cellular respiration to produce energy.

True or false: Lungs only absorb oxygen.

False, because they also expel carbon dioxide.