Cystic Fibrosis Flashcards
what is cystic fibrosis
defective chloride channels in the cellular membrane
what does this defect lead to
hyper secretion of exocrine glands
Aetiology of Cystic Fibrosis
CFTR gene on Chr 7
- cystic fibrosis transmembrane regulatory protein
Monogenic (controlled by a single gene)
autosomal recessive (needs two copies of this single gene)
Patho of cystic fibrosis
cystic fibrosis transmembrane regulatory protein forms CL channel on epithelial cells
- if protein doesn’t form then you don’t have the pathway
- Cl ions will not be able to move across the membrane
What occurs when there are mutations of the genes that code for the CFTR protein
mutations make cells impermeable to Cl - impaired Cl transport across cell membrane - abnormal secretion
what is occuring
Chloride is no longer drawn out of the ASL as well as the the channel that pulls out sodium is no longer inhibited
What happens when sodium leaves the ASL
water follows, dehydrating the mucous layer =more sticky
what are you at risk for
recurrent infections due to proliferation in the environment
sticky mucous secretions cause what
decrease in ciliary function
plugs airway
decrease rest function
Diagnosis of CF
sweat test
CF in sibling (genetics)
newborn screening
GI and Resp manifestations
what is the sweat test
because the sodium is no longer inhibited it freely leaves the ASL(airway surface liquid) And can be excreted out the sweat gland
the sweat test tests your sweat for this sodium and should see 2-5 x the
amount that you usually would
what is the newborn screening tool
you test for trypsinogen in the blood (inactive substance secreted by the pancreas)
Treatment for CF
no cure = rest failure
DNAase- enzyme that breaks down DNA released by dying cells
prophylaxis treatment- control other infections that may occur
diet modifications and pancreatic Enzyme supplement
anti-inflammatory drugs
