Ex. 37

A pneumothorax occurs when the pleura is punctured, and air becomes trapped in the thoracic cavity, the resulting pressure collapses the lung. To restore the negative pressure, an incision through the chest wall is made to release the air.

Atelectasis is a collapsed lung. Explain how a pneumothorax might result in a collapsed lung and what should be done to restore the negative pressure of the pleural cavity.

Air flows out of the lungs Diaphragm and external intercostals relax Intrapulmonary pressure increases Thoracic cavity volume decreases

Expiration

hypercapnia

Higher than normal CO2 in the blood

Air flows into the lungs Diaphragm and external intercostals contract Intrapulmonary pressure decreases Thoracic cavity volume increases

Inspiration

dyspnea

Labored breathing is called

Vital capacity will decrease because the deformed ribcage limits the volume of air that can be inhaled.

Pectus excavatum is a condition in which the anterior thoracic cage is caved inward because of abnormal development of the sternum and ribs. What effect would you expect this condition to have on vital capacity, and why?

3.71 L

Predict the vital capacity of a 20-year-old 5'5" female who weighs 120 pounds using the equation below: VC = (0.041) H - (0.018) A - 2.69

Balloons inflate Volume inside bell jar increases Pressure inside bell jar decreases

Rubber diaphragm down

Balloons deflate Volume inside bell jar decreases Pressure inside bell jar increases

Rubber diaphragm up

bronchioles

Small air passages less than 1 mm are called

respiratory volumes

What does a spirometer measure?

Pulmonary ventilation

What is the mechanical process of moving air into and out of the lungs?

The presence of air in the pleural cavity.

Which of the following statements describes the conditions of a pneumothorax?

pneumothorax

is the presence of air in the pleural cavity, which inhibits breathing.

-capnia

means carbon dioxide in blood.

Total lung capacity (TLC)

the maximum amount of air contained in the lungs after a maximum inspiration

Vital capacity (VC)

the maximum amount of air that can be expired after a maximum inspiration

Inspiratory capacity (IC)

the maximum amount of air that can be inspired after a normal expiration

Tidal volume (TV)

volume of air inhaled or exhaled with each breath under resting conditions

Residual volume (RV)

volume of air remaining in the lungs after a forced expiration

Functional residual capacity (FRC)

volume of air remaining in the lungs after a normal expiration

Expiratory reserve volume (ERV)

volume of air that can be forcefully exhaled after a normal expiration

Inspiratory reserve volume (IRV)

volume of air that can be forcefully inhaled following a normal inspiration