Question

How does an asthma attack cause difficulty in breathing? Emphysema from smoking and exposure to heavy pollution causes alveoli to expand and rupture. Describe how this would compromise respiratory function. Describe how skeletal muscles are used for inhalation. Use Boyle’s law to explain the process of pulmonary ventilation. Describe how to calculate inspiratory reserve volume. How did your vital capacity compare to your calculated predicted vital capacity? What health and lifestyle behaviors impact your vital capacity? Would a subject hold her or his breath longer after hyperventilating or after hypoventilating? Explain your answer. What changes occur in the body as a person hypoventilates? How does the body adjust respiratory rate and depth to counteract the effect of hypoventilation? Using your current height and gender, calculate your predicted vital capacity but add 5 years to your current age. Then, do the calculation again, but add 10 years to your current age. What changes are predicted in vital capacity as one ages? What do you think the reasons are for these age-related changes?

Answer 1

1. Causes smooth muscle of the bronchial tree to constrict and the air is narrowed. Exhalation is difficult because the pressure to force air out of the lungs collapses the narrow bronchioles and increases the resistance for breathing.

2. Emphysema causes expanded and ruptured alveoli in the lungs, resulting in a reduction of the pulmonary surface area for exchange of gases.

3. External intercostal muscles contract to elevate the ribs, and the diaphragm contracts to increase the volume of the thoracic cavity. Both of these actions increase the volume of the lungs and therefore decrease intrapulmonic pressure below the pressure of the atmosphere. Air now flows down the pressure gradient from the atmosphere and into the lungs

4. Pressure of the gas, in a closed container, is inversely proportionate to the volume of it container. This gas law explains how changing the size of the thoracic cavity and the lungs modifies pulmonary pressures for ventilation. During inhalation, the diaphragm drops and the ribs swing upward. These actions enlarge the chest and lungs, and pulmonary pressures decrease. Air flows down its pressure gradient from the atmosphere to the lungs. During exhalation, the ribs depress and the diaphragm relaxes to decrease the size of the lungs and increase pulmonary pressures to force air out

5.The vital capacity, expiratory reserve volume, and tidal volume are known. IRV=VC-(TV+ERV)

6.Vital capacity will vary. Good respiratory fitness and a lifestyle that includes exercise, not smoking, a balanced diet, healthy environmental conditions, and family genetics can influence pulmonary function