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27 Cards in this Set
- Front
- Back
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What is cystic fibrosis?
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It is adisease characterized by frequent serious respiratory infections, thick sticky mucus in the lungs and digestive tract, and a salty taste to the skin.
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What is the CFTR gene?
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This is agene in the disease that results in the production of a defective chloride channel.
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What are the 2 major functions of CFTR?
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1. It is a Cl- channel, which transports chloride across the plasma membrane of epithelial cells,
2. Regulator of epithelium sodium channels. |
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Over 70% of CF cases result from the loss of the amino acid phenylalanine from the CFTR protein. TRUE/FALSE
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TRUE.
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What does CFTR stand for?
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Cystic fibrosis transmembrane conductance regulator.
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Because of the phenynlalanine defection, the CFTR is not transported to the plasma membrane. TRUE/FALSE
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TRUE.
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The ciliated epithelium of the tracheobronchial tree are located in a layer referred to as...
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Periciliary layer. It is app. 7um thick, which is the length of a fully extended cilium.
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Is there a layer of mucus that overlies the PCL?
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Yes. It varies in height from 7-70um. It can trap microorganisms and inhaled debris.
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What happens when there is abeating of the cilia?
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It moves the PCL and the overlying mucus of the respiratory system.
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Why must the normal height of the PCL be maintained?
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For optimal movement of the mucus. Changes in the PCL volume change the height of the PCL.
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Regarding the previous statement, why is this so?
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Water movement between the mucus and PCL and across the layer of epithelial cells lining the respirator tract alters PCL volume. The mucus acts as a reservoir to store and release water.
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Can you give an example for the above statement?
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As PCL volume decreases, the mucus replenishes the volume by releasing water into the PCL.
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How do respiratory epithelial cells regulate PCL volume?
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By controlling the movement of Na+ and Cl-. As these ions move out of or into, the PCL, water follows. Two opposing systems regulate the movement of Na+ and Cl-.
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What happens when the Na+ system is dominant?
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Na+ are absorbed from the PCL, Cl- and water follow, and PCL volume is reduced.
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What happens when the Cl- system is dominant?
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Cl- are secreted into the PCL, Na+ and water follow, and PCL volume is increased.
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In addition to functioning as Cl- channels, CFTR inhibits the activity of the Na+ channels. TRUE/FALSE
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TRUE. CFTR usually acts as a brake on the Na+ channels, thereby reducing the amount of sodium normally reabsorbed.
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What happens to CFTR in cysytic fibrosis?
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It is either nonfunctional or marginally functional. The normal inhibition of the Na+ channels is lost or diminished and Na+ absorption increases dramatically, resulting in increased water loss from the PCL. Water is lost as well from the mucus. The mucus is thicker than normal.
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What is the sweat chloride test?
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The chemical pilocarpine is swabbed onto the skin and a mild electric current is applied.
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What is pilocarpine?
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It is a muscarinic agent that stimulates receptors in the sweat glands.
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What is the function of the electric current?
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It drives the medication into the skin, resulting in localized sweating and avoiding systemic drug effects. The sweat produced is collected and tested for high levels of NaCl.
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Normally swaet glands produce a very dilute liquid, which cools the body without depleting the salt from it. TRUE/FALSE
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TRUE.
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What happens to the sweat in CF?
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The malfunctioning of CFTR results in a failure to absorb the normal amount of Na+cl_ from sweat. This results in sweat with an abnormally high content of salt.
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Can CF affect other organ systems?
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Yes. The original name was CF of the pancreas, because in 90% of CF patients, the pancreas is slowly destroyed and infiltrated by fibrous cysts.
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Why can children with CF have severe nutrional deficiencies?
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The pancreatic ducts can become obstructed, and the decreased absorption of proteins and fat soluble vitamins can be the cause of the deficiency.
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What is chest clapping?
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This is a type of therapy, which involves manually pounding of the back and chest for 30-40 minutes 3-4 times daily to dislodge mucus.
Antibiotics are commonly used. |
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What is Pulmozyme?
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It is a mucus thinning drug.
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Is a lung transplant considered a cure?
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IT is considered a partial cure, because the transplanted lung cells do not have the genetic defect.
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