Mechanics of Breathing Quiz

What is the intrapleural pressure at rest in millimeters of mercury?

• -4 mmHg

• -6 mmHg

• 760 mmHg

• 0 mmHg

During inspiration, how does the intrapulmonary pressure change?

• Decreases to -1 mmHg

• Increases to 760 mmHg

• Increases to +1 mmHg

• Remains at 0 mmHg

What happens to intrapulmonary pressure at the peak of inspiration?

• It decreases below atmospheric pressure

• It remains unchanged

• It becomes equal to atmospheric pressure

• It increases above atmospheric pressure

Which muscles are primarily involved in quiet inspiration?

• Sternocleidomastoid and Scalenes

• Internal Intercostals

• External Intercostals and Diaphragm

• Pectoralis Minor

What is the role of the sternocleidomastoid in forced inspiration?

• Decreases thoracic cavity volume

• Increases intra-abdominal pressure

• Helps pull the sternum outwards

• Contracts to relax the diaphragm

How does forced inspiration affect thoracic cavity volume compared to quiet inspiration?

• Increases it more significantly

• Decreases it slightly

• Has no effect on it

• Decreases it significantly

During quiet expiration, what primarily drives the air out of the lungs?

• Contraction of abdominal muscles

• Elastic recoil of the lungs

• Active use of the diaphragm

• Increase in intrapleural pressure

What triggers the relaxation of muscles during quiet expiration?

• Contraction of the diaphragm

• Inhibition of inspiratory neurons

• Activation of expiratory neurons

• Increase in intrapleural pressure

What is the primary function of the diaphragm during inspiration?

• To relax and allow air in

• To decrease thoracic cavity volume

• To contract and push air out

• To increase thoracic cavity volume

What is Boyle's law's relevance to the mechanics of breathing?

• Volume of a gas decreases with temperature

• Pressure of a gas increases with temperature

• Volume and pressure of gases are inversely proportional

• Volume and pressure of gases are directly proportional