1. Short Answers:  Define hematocrit
(1 point). Explain the physiological mechanisms that contribute to
Joe’s high hematocrit (4 points).

Joe Smith is a 69-year-old male with a 50-year history of
smoking 2 packs of cigarettes a day (i.e. 100-pack-year smoking
history). Over the past 5 years, he has become increasingly short
of breath. At first, he noticed this only when exercising, but now
he is even short of breath at rest. Over the past two years, he has
had several bouts of lower respiratory tract infection treated
successfully with antibiotics. His shortness of breath hasn’t
subsided, and his breathing is assisted by use of his accessory
muscles of respiration. Pulmonary function testing and blood
testing results are shown below.