CF

• how does excess water in mucus move in normal person?

  1. Na actively pumped across basal membrane
  2. Na diffuses through sodium channels in apical membrane
  3. Cl diffuses down electrical gradient
  4. water drawn out cells via osmosis due to high salt concentration in fluid
  5. water drawn out of mucus via osmosis
• too little water in mucus for normal person?

  1. Cl pumped into cell across basal membrane
  2. Cl diffuses through open CFTR channels
  3. Na diffuses down electrical gradient into mucus
  4. elevated salt concentration in mucus draws water out of cell via osmosis
  5. water drawn into cell via osmosis
• CF sufferer?

  1. CFTR channel is absent or not functioning
  2. Na channel permanently open
  3. Water constantly removed from mucus via osmosis
• what systems does it mainly affect?

  • digestive
  • reproductive
  • respiratory
• role of mucus?

  coats tubes of gas exchange system, produced by goblet cells.

  • mucus traps dust debris and microorganisms
  • cilia help to remove mucus by wave-like beating
• what are the major effects of health?

  • increased chance of lung infections: due to pathogens thriving from lack of oxygen in mucus. WBC that try to fight off bacteria and die, contents making mucus even more sticky and increasing more infection chances
  • blocking bronchioles presents efficient ventilation for alveoli: reduction in surface area for gas exchange= lack of oxygen so difficult for physical exercise !
• role of mucus and how its removed?

  trap any dust/microorganisms from getting into lungs, removed via cilia in epithelial cell lining of respiratory system by wave like beating and coughed up/swallowed to be destroyed by stomach acid.