Cystic Fibrosis Flashcards
What is the primary cause of cystic fibrosis?
A defect in the gene that codes for cystic fibrosis transmembrane conductance regulator
How does the CFTR chlorine channel normally function?
The CFTR channel pumps chloride ions out of the epithelial cells
The activation of the channel allows the functioning of surrounding chloride channels
The sodium transporter is inhibited meaning sodium cannot enter cells
This means osmosis will be directed outwards into the airways keeping them moist
How does a CFTR mutation cause cystic fibrosis in the airways?
Chlorine cannot be transported across the cell membrane via the CFTR channel or the surrounding chloride channels which can now be activated
Inhibition of the sodium ion transporter ceases
Sodium enters the cell reversing the osmotic gradient into the cell
This dries out the air wards creating thick sputum
What is the most common mutation in cystic fibrosis?
Deletion of phenylalanine at position 508
What is a promising therapy for cystic fibrosis?
Lumacaftor ( a drug that acts as a chaperone during protein folding and increases the number of CFTR proteins that are trafficked to the cell surface)
How is cystic fibrosis treated if infected with staph aureus?
Oral flucloxacillin
Oral septrin
How is cystic fibrosis treated if infected with pseudomonas?
- Oral azithromycin
- Nebulised colomycin
- Nebulised or inhaled tobramycin
- Nebulised aztreonam
Cystic fibrosis affects the lungs, but which other parts of the body are affected?
- Pancreas
- Bowels
- Liver
How does cystic fibrosis affect the exocrine function of the pancreas?
Pancreatic ducts are blocked and lipases and amylase cannot be secreted
Digestive failure occurs
How can the exocrine functioning of the liver be treated when cystic fibrosis is present?
CREON
pancrelipase
How does cystic fibrosis affect pancreatic endocrine function?
Pancreatic islet cells are destroyed and replaced with fatty tissue
This can cause diabetes and insulin needs to be administered
How can the bowels be affected by cystic fibrosis?
Distal intestinal obstruction syndrome
Mucus blocks the small and large intestines
How is distal intestinal obstruction syndrome (DIOS) treated?
Additional fluids
Gastrografin- a contrast medium to locate areas of bloackage
Laxido (laxative)
How can the liver be affected by cystic fibrosis?
Hepatic ducts become blocked
This can lead to portal hypertension causing variceal bleeding
What is hepatic encephalopathy?
A decrease in brain function due to brain damage by a build up in toxins the liver fails to remove
