Cystic Fibrosis: SAQ Solutions

Listed below are the solutions to the SAQs on Cystic Fibrosis:

1. Lungs and Pancreas
   Mucus build up in the lungs affects air flow and mucus build up in the pancreas affects secretion of digestive enzymes.
2. A. Blood clotting
   Because lung function is compromised, respiration is affected in CF patients. Because of an inability to secrete sufficient digestive enzymes into the small intestine, both digestion and waste secretion are affected.
3. Poiseuille’s Law or Equation
   Poiseuille’s Law relates the radius of an idealized tube to resistance of that tube in laminar fluid flow conditions by taking into account fluid properties such as viscosity.
4. B. Q ∝ a^4
   Poiseuille’s Law says that airway resistance (R) and airway radius (a) are related by R ∝ 1/a^4. Airway resistance is related to airflow in turn by the equation Q = ∆P/R, so Q ∝ a^4 is the correct relationship.