Question

1. patient enters your respiratory laboratory complaining of feeling lightheaded. You measure their tidal volume at 100ml per breath and respiratory frequency at 58 breaths per minute, an investigation of their lung capacity reveals a measured anatomic dead space of 90ml.

1a. What is their Minute Ventilation? Show all work. (2pts)

1b. What is their Alveolar Ventilation? Show all work. (2pts)

1c. Assuming their metabolism in normal, are they Hypo- or Hyper- ventilating, Explain your reasoning. (2pts)

1d. What should they do to relieve their lightheadedness? (2pts)

2. A crazed cardiologist has severed the bundle of HIS fibers in her patient’s heart. Draw a picture of what the patients EKG pattern would look like immediately after surgery (assuming the patient survives). Label the P, QRS and T waves. (3pts)

3a. A patient in your care has a pulse of 70 BPM, an end-systolic volume of 120ml. and an end-diastolic volume of 135ml. What is their Cardiac output? (4pts)

3b. Is the patient described above healthy? Give a physiologically plausible explanation of your diagnosis. Ie. what might be the cause of these results. (2pts)     

4. Describe the forces that determine the magnitude of the GFR. What is a normal value of GFR? (8 points)

5. Describe the process of fat emulsification. Additionally, describe the movement of fat digestion products from the intestinal lumen to a lacteal. (5 points)

Answer 1

Answer 1a:

Given; Tidal volume = 100 ml, Respiratory rate = 58 breaths/minute, Anatomical dead space = 90 ml.

Minute Ventilation = Tidal volume x Respiratory rate

= 100 x 58

= 5800 ml/min

Hence Minute ventilation is 5800 ml/min

Answer 1b:

Alveolar ventilation = (Tidal volume - Anatomical dead space) x Respiratory rate

= (100 - 90) x 58

= 10 x 58

= 580 ml/min

Hence Alveolar ventilation rate is 580 ml/min

Answer 1c:

This is the case of Hyperventilation because Respiratory rate is 58 breaths per minute which is very much above the normal respiratory rate of 12 to 16 breaths per minute for adults. Hyperventilation is rapid breathing or deep breathing.

Answer 1d:

Hyperventilation or rapid breathing leads to reduction of carbon dioxide in body. Low carbon dioxide levels causes narrowing of blood vessels which supplies blood to the brain due to which lightheadedness happens. To relieve lightheadedness the blood supply to brain has to increased by breathing slowly, by holding the breath, by reducing stress, by meditation, by acupuncture or by taking medicines.