Question | Answer |
What type of inheritance in CF? | Autosomal dominant |
What to organs/ systems does CF affect? | Lungs + GIT |
What is the result of the defective gene? | Production of unusually thick sticky mucus |
What are the two main results of this think sticky mucus? | Clogs the lungs and clogs the pancreas |
What is the result of the mucus clogging the lungs? | Life-threatening lung infections |
What is the result of the mucus clogging the pancreas? | Stops enzymes being released that help break down and absorb food |
What are the six symptoms?
1. Taste?
2. Lungs? (3)
3. Poor...but good...?
4. Frequent...? | 1. Salty tasting skin
2. Coughing, wheezing and frequent lung diseases
3. Poor growth but good apetite
4. Frequent greasy, bulky stools |
Sweat glands (normal) - Fluid produced in secretory coil is rich in? | NaCl |
Sweat glands (normal) - NaCl secretion is modified in the duct by? | NaCl reabsorption (without H2O) |
Sweat glands (normal) - If NaCl is reabsorbed without H2O, the solution becomes more hypertonic/hypotonic/ same? | Hypotonic |
Sweat glands (normal) - The duct lumen has a -ve/+ve/ same electrical charge when compared to outside the duct? | -ve |
Sweat glands (normal) - So lumen is -vely charged, how do Na+ ions get reabsorbed? | Actively pumped out |
Sweat glands (normal) - So lumen is -vely charged, how is cl- reabsorbed? | Passive movement through Cl- channels |
Sweat glands (CF) - Therefore what is the pathophysiology in CF? | Defect Cl- channels (with low permeability) -> secretion remains -vely charged. |
Pancreas duct cell (normal) - What is actively pumped out of the apical membrane into the lumen? | Cl- |
Pancreas duct cell (normal)- Is Cl- being pumped into lumen active/ passive? | Active |
Pancreas duct cell (normal) - HCO3- is needed in the stomach to do what? | Neutralize stomach acid |
Secretory glands (normal)- Is HCO3- pumped into/ out of the lumen? | Into |
Secretory glands (normal)- What is HCO3- exchanged for when pumped into the lumen? | Cl- |
Pancreas duct cell (normal)- When being exchanged for HCO3-, does Cl- move up/down its concentration gradient? Why? | moves down its concentration gradient due to active pumping of Cl- into lumen |
Pancreas duct cell (CF)- What does a deficient cAMP/Cl- pump lead to? (2) | Decreased Cl- to exchange for HCO3-, therefore less HCO3- in secretion (in lumen) |
Pancreas duct cell (CF)- What does decreased HCO3- in secretion lead to? (2) -> (1) | Mucins are poorly solublized and less transportable -> stasis of mucus |
What gene codes for the chloride channel? | CFTR gene |
What is the Cl channel activated by? | Phosphorlyation |
What is the genetic mutation present in CFTR gene that causes CF? (1) | Deletion of three bases |
What does the deletion of 3 bases in the CTFR gene lead to? (3) | Misfolding of channels -> degredation of channels --> decreased concentration of Cl- channels in CF patients |
How could gene therapy be used as a potential cure for CF? | Replace the faulty CFTR gene with a normal one |
*For treatments see flow | |
Lungs (normal) - What is the role of CFTR channels? | Secretion of Cl- (fluid) |
Lungs (normal) - What is the role of ENaC channels? | Absorption of Cl- (fluid) |
Lungs (normal) - What is the interaction between CFTR and ENaC? | Work in balance |
Lungs (CF) - What does the down regulation of CFTR lead to? (Increased/ decreased -> ?) | Decreased secretion and increased absorption leading to volume depletion |
Lungs (CF) - What does volume depletion lead to? | Decreased mucociliary clearance |
Lungs (CF) - What is the treatment? | Block ENaC channels -> No absorption or secretion |