Exam 3 Review:  Chapter 22:  Spirometry

spirometer - An instrument for measuring the volume of air entering and leaving the lungs and recording the volumes moved during different types of breathing on a graph.

spirogram - A record of breathing made with a spirometer.

tidal volume - The amount of air moved in and out of the lungs with each relaxed or resting breath; usually about 0.5 L; ~70% of this volume reaches the respiratory section of the lungs, and ~30% remains in the conducting section of the lungs (the anatomic dead space).

anatomic dead space - The total volume of the conducting airways from the nose or mouth down to the level of the terminal bronchioles; normally it is ~0.15 L (~30% of a tidal volume); this air is "wasted" in the sense that it does not participate in gas exchange.

minute volume of respiration - The total volume of air ventilated over a period of one minute.

alveolar ventilation rate - The portion of the minute volume of respiration/ventilation which reaches those areas of the lung concerned with gas exchange; normally it is ~3.5 to 5.0 liters per minute; this measue of external respiratory function is, perhaps, the best criterion for effectiveness of breathing.

inspiratory reserve volume - The amount of air which can be taken into the lungs, beyond one's tidal volume, using a forced inspiration; normally it is ~3.0 L of air.

expiratory reserve volume - The amount of air which can be forced out of the lungs by contracting the chest and abdominal muscles beyond tidal volume ventiliation; normally it is ~1.5 L.

forced expiratory reserve volume - The volume of air which can be expelled from the lungs in a prescribed amount of time (FEV₁ = for 1 second,  FEV₂ = for 2 seconds,  FEV₃ = for 3 seconds, etc.) with a maximal effort following a maximal inhalation; in cases of COPD, (Chronic Obstructive Pulmonary Disease), e.g., in cases of asthma and emphysema, the FEV is low, while the total lung capacity, functional residual capacity, and residual volumes are high; in restrictive pulmonary diseases, the vital capacity, total lung capacity, functional residual capacity and residual volume are low due to the inability of the lungs to expand.

residual volume - The amount of air remaining in lungs even after deepest possible expiration; normally it is ~1.0 L; (it cannot be directly measured by spirometry); this "dead air" decreases the efficiency of gas exchange by diluting the oxygen of the inspired air.

inspiratory capacity - The maximum volume of air which can be inspired into the lungs after the end of a tidal or resting exhalation; normally it is ~3.5 L; it is equivalent to the sum of the inspiratory reserve volume and the tidal volume.

functional residual capacity - The amount of air remaining in lungs after the end of a tidal or resting exhalation; normally it is ~1.5 L; it is equivalent to the sum of the expiratory reserve volume and the residual volume.

vital capacity - The maximum volume of air that can be moved in and out of the lungs during a single breath; normally it is ~5.0 L; it is equivalent to the sum of the tidal volume, the inspiratory reserve volume, and the expiratory reserve volume; it varies depending on body size, fitness level, and degree of health or disease.

total lung capacity - The total amount of air contained in the lungs after the deepest possible inhalation; normally it is ~6.0 L; it is equivalent to the sum of the tidal volume, the inspiratory reserve volume, the expiratory reserve volume, and the residual volume; it varies depending on body size, fitness level, and degree of health or disease.

The Volumes and Capacities Derived from Spirometry:

SPIROMETRY EQUATIONS FOR RESPIRATORY CAPACITIES:

Total Lung Capacity = Inspiratory Reserve Volume (IRV) + Tidal Volume (TV) + Expiratory Reserve Volume (ERV) + Residual Volume (RV)

Inspiratory Capacity = Inspiratory Reserve Volume (IRV) + Tidal Volume (TV)

Functional Residual Capacity = Expiratory Reserve Volume (ERV) + Residual Volume (RV)

List:

3. The lung volumes and capacities. Distinguish between a lung volume and a lung capacity.

Sketch and label:

3. A spirogram.