Which of the following exocrine glandular ducts are not obstructed in cystic fibrosis

Abnormal Characteristics of CF Patients * The ducts of the mucus secreting glands are obstructed because of high viscosity of these secretions which leads to glandular dilatation and destruction. * The ducts of sweat glands are free from obstruction because the sweat gland has abnormal concentrations of inorganic ions, rather than glandular obstruction with thick mucus. Method of diagnosing CF:- Quantitative pilocarpine iontophoresis sweat test. * Airway obstruction causes bronchiectasis and atelectasis * Obstruction in pancreatic duct causes pancreatitis and malabsorption * Obstruction of bile ducts leads to obstructive jaundice. Ref:- Robbins pathological basis of disease 9th Edition; Pg Num:- 466