3 - Cystic Fibrosis Flashcards
What type of cells are affected by cystic fibrosis?
Epithelial
Cystic fibrosis affects the movement of which ions?
Cl-
Why are epithelial cells able to move materials into one side and out the other?
They are polarized
What are the 4 main organs affected by cystic fibrosis?
- Lungs
- Pancreas
- Sweat glands
- Male reproductive tract
What proportion of Caucasians are carriers for cystic fibrosis?
1 in 25
What proportion of Caucasians are diagnosed with cystic fibrosis?
1 in 2500
Cystic fibrosis is the result of a mutation on which chromosome?
7
In cystic fibrosis, an amino acid is deleted from which gene?
CFTR gene
How does the mucociliary escalator protect against infection?
Cilia beat pathogen-trapping mucus into the oropharynx where it can be swallowed
Why is someone with cystic fibrosis more likely to suffer repeated lung infections?
Thickened mucus traps pathogens
Pancreatic lipase aids in ___ absorption.
Fat
Why does cystic fibrosis lead to poor fat absorption?
Thickened mucus blocks pancreatic lipase from reaching the small intestine
What is steatorrhea?
Fatty stools
How does cystic fibrosis lead to salty sweat?
Due to a dysfunctional CFTR channel, Cl- (and thus Na+) is not reabsorbed by the sweat glands
How does cystic fibrosis lead to an early death?
Recurrent lung infections damage the airways
What is the current life expectancy for cystic fibrosis?
40 years
What percentage of cystic fibrosis patients make their teenage years?
90%
Compare type 1 and type 2 thinking.
Type 1: fast, instinctive, usually correct
Type 2: slow, deliberate, often incorrect
Two cystic fibrosis carriers have a child. What are the odds that the child will be a carrier?
1 in 2
List 6 symptoms of cystic fibrosis.
- Recurrent chest infections
- Coughing
- Wheezing
- Shortness of breath
- Fatty stools
- Failure to thrive
What type of epithelium lines the upper respiratory tract?
Pseudostratified columnar ciliated
Name the unicellular glands within the respiratory and GI tracts that secrete mucus.
Goblet cells
How does physiotherapy help with cystic fibrosis?
Clears mucus from the airways
What pharmacological agents are commonly used to combat lung infections in cystic fibrosis?
Antibiotics
What is the medical term for swollen fingernails?
Clubbing
List 3 types of dietary supplements for cystic fibrosis patients.
- Pancreatic lipase supplements
- Vitamins A, D, E, and K
- Calcium
How does cystic fibrosis affect the male reproductive tract?
Absence of the vas deferens means sperm can be made but not ejaculated
A newborn with cystic fibrosis will have ___ sodium levels in the sweat.
High
Explain how cystic fibrosis causes thick mucus.
Defective CFTR channel -> Cl- trapped in cell -> Na+ follows -> Water follows Less water in mucus
Water follows Na+ across the cell membrane due to what phenomenon?
Osmosis
Why would Na+ follow Cl-?
Cations and anions travel together to maintain ELECTRO-NEUTRALITY
A patient with cystic fibrosis uses a DNase spray. What is the origin of the target DNA?
White blood cells collecting to fight infection
What pharmacological treatment would break down excess DNA?
DNase spray
Define hypoxia.
Low oxygen in blood
What causes clubbing of the fingernails?
Long-term hypoxia
List 4 conditions that could lead to clubbing of the fingernails. (Hint: involve long-term hypoxia.)
- Lung cancer
- Sarcoidosis
- Tuberculosis
- Tetralogy of Fallot
List 4 vitamins whose absorption is hindered in cystic fibrosis patients. (Hint: fat-soluble).
- A
- D
- E
- K
Why are pancreatic secretions trapped in cystic fibrosis?
Thickened mucus sticks them in place
Who is unlikely to be a cystic fibrosis carrier?
People of colour
What is genetic drift
Change in allele frequency caused by chance (visualize: natural disaster)
What are the 5 principles of Hardy-Weinberg equilibrium?
- No MUTATIONS
- No MIGRATION
- No GENETIC DRIFT
- No NON-RANDOM MATING
- No NATURAL SELECTION
Remember: Marilyn Monroe Gets Naked Nightly
Describe 3 principles of treatment for cystic fibrosis.
- Fight INFECTION (antibiotics)
- Clear AIRWAYS (physiotherapy, mucus-thinning medication)
- Ensure proper NUTRITION (rich diet, vitamins)
