Lung Volume PDF

Lung Volume Outcome D1b, Lesson 3 Lung Volume Lung volume or lung capacity is the maximum volume of air that can be held in the lungs The lung volume of the average male adult is 6 L with the average female capacity being that of 10-12% smaller (5.2-4 L) Lung volume is affected by h...

Lung Volume Outcome D1b, Lesson 3 Lung Volume Lung volume or lung capacity is the maximum volume of air that can be held in the lungs The lung volume of the average male adult is 6 L with the average female capacity being that of 10-12% smaller (5.2-4 L) Lung volume is affected by height and gender which changes the size of the thoracic cavity and the lungs However, during quiet breathing, only about 0.5 L of air is inhaled and exhaled Spirometer A spirometer is a device that measures lung capacity Wet Spirometer Type of spirometer we will use Has a tube that you breath into that is connected to an upside-down container floating on water Spirograph A spirograph represents the amount of air moving in and out of the lungs with each breath Spirograph Tidal volume – the volume of air breathed in and out in one normal breath Typically, around 0.50 L of air Only about 0.35 L actually reach the alveoli, the rest fill the trachea, bronchi, and bronchioles With an average respiratory rate of 12-20 breaths per minute, that is 4.2 - 7 L of air exchanged per minute Spirograph Inspiratory reserve volume – the additional volume of air that can be inhaled This is in addition to a normal breath (tidal volume) Involves expanding the lungs to a greater extent than normal as well as recruiting the neck and abdominal muscles in addition to the diaphragm and intercostal muscles Expiratory reserve volume – the additional volume of air that can be exhaled The air that is forced out of the lungs after a normal breath has already exited Spirograph Inspiratory capacity – total amount of air that can be inhaled Tidal volume + Inspiratory reserve volume Vital capacity – the total volume of gas that can be moved in and out of the lungs Inspiratory capacity + Expiratory reserve volume Spirograph Residual volume – the amount of gas that always remains in the lungs and passageways even after forced exhalation Approximately 1 L of air Why is this necessary? So the lungs and respiratory passages do not collapse Total lung volume – the total amount of gas that can be held in the lungs Residual volume + Vital capacity Lung Volume What do you think would happen to your lung volume and capacity if you were training for a marathon? Exercise performed over an extended period of time will strengthen the muscles involved in breathing, which will increase tidal volume and vital capacity Lung Volume What do you think would happen to your lung volume and capacity if you were sick with the flu? Illness can reduce vital capacity and tidal volume by affecting the number of alveoli that can successfully exchange, or by weakening the muscles involved in breathing  Tidal Volume Vital Capacity Respiratory rate at Patient (mL) (mL) rest (breaths/min) 1 500 5000 18 (normal) 2 500 4000 20 3 400 3000 38 4 550 5000 17 5 550 6000 17 What is the difference between tidal volume and vital capacity? Which patient is likely a long-distance runner? Which patient likely suffers from a respiratory disorder?  Tidal Volume Vital Capacity Respiratory rate at Patient (mL) (mL) rest (breaths/min) 1 500 5000 18 (normal) 2 500 4000 20 3 400 3000 38 4 550 5000 17 5 550 6000 17 What is the difference between tidal volume and vital capacity? Tidal volume shows regular breaths while vital capacity shows the maximum amount of air that can be inhaled/exhaled  Tidal Volume Vital Capacity Respiratory rate at Patient (mL) (mL) rest (breaths/min) 1 500 5000 18 (normal) 2 500 4000 20 3 400 3000 38 4 550 5000 17 5 550 6000 17 Which patient is likely a long-distance runner? 5 – they have a large vital capacity and a low respiratory rate  Tidal Volume Vital Capacity Respiratory rate at Patient (mL) (mL) rest (breaths/min) 1 500 5000 18 (normal) 2 500 4000 20 3 400 3000 38 4 550 5000 17 5 550 6000 17 Which patient likely suffers from a respiratory disorder? 3 – they have a low tidal volume (airways may be constricted) and a high respiratory rate