Cystic Fibrosis BD 2011

How cystic fibrosis affects the lungs Sticky mucus builds up in the airways, reducing flow of air into alveoli. Lungs gradually fill up with mucus, making them less effective for gas exchange. Symptoms: Severe coughing - to remove excess mucus. Breathlessness - shortage of oxygen increases tiredness and lack of energy Infections - as bacteria are trapped in mucus

How does cystic fibrosis affect the reproductive systems? Men Women Sperm duct is blocked and prevents movement of sperm During the menstrual cycle the levels of mucus vary. Can lack the sperm ducts Women with CF have thick levels of mucus which can block the cervix so sperm cannot reach them.

How cystic fibrosis affects the digestive system: Thick, sticky mucus blocks the pancreatic duct preventing enzymes from reaching the duodenum. Food is not digested and absorbed sufferers fail to put on body mass and suffer malnutrition. Trapped digestive enzymes damage the pancreatic cells affecting cells producing insulin resulting in diabetes.

What causes Cystic Fibrosis? A mutation in the cystic fibrosis transmembrane regulatory protein

What does the CFTR protein do? It helps control the viscosity (or stickiness) of mucus that lines the epithelial cells of the airways, digestive and reproductive systems mucus cilia epithelial cell If the mucus in airways is… too sticky: the cilia cannot beat and remove the mucus, which then clogs up airways too runny: the mucus can flood the airways

Mucus with excess water Open Na+ channel Mucus Mucus with excess water Apical membrane Cl- 1. Na+ is actively pumped across the cell basal membrane H2O 2. Na+ diffuses through the open sodium channels in the apical membrane CFTR Channel closed 3. Cl- diffuses down electrical gradient. Epithelial cells 4. Water is drawn out of the cell by osmosis into the high Na+ and Cl- concentration of the tissue fluid. H2O Sodium (Na+)pump Cl- pump 5. Water is drawn out of the mucus by osmosis. Tissue fluid Na+

Mucus with too little water Closed Na+ channel Mucus Mucus with too little water Apical membrane 1. Cl- is actively pumped into the cell across basal membrane 2. CFTR channel opens and Cl- diffuses out of the cell into the mucus. CFTR Channel open H2O 3. Na+ diffuses down the gradient into the mucus. Epithelial cells 4. Elevated Na+ and Cl- (salt) in the mucus draws water out of the cell by osmosis. 5. Water is drawn into the cell by osmosis. Sodium (Na+)pump Cl- pump H2O Na+ Cl- Tissue fluid

1. CFTR Channel is absent or non functional H2O Open Na+ channel Mucus Cystic Fibrosis Apical membrane Cl- 1. CFTR Channel is absent or non functional H2O 2. Na+ channel is permanently open. CFTR Channel Non functional 3. Water is continually drawn from the mucus by osmosis. Epithelial cells H2O Sodium (Na+)pump Cl- pump Tissue fluid Na+