Homeostasis is the process of maintaining equilibrium within the internal environment known as extracellular fluid. The cellular mechanism is “how” variable regulate during each step of the feedback loop. People affected with CF have a defective Cystic Fibrosis Transmembrane Regulator (CFTR) gene, that stop the movement of chloride ions from entering and leaving the cell which is important for salt and water balance on the surfaces. The dysfunction of the CFTR channel inhibits the flow of water which lead to mucus dehydrated and thicken, making it difficult to clear the mucus.(Shannon Stephen) The cellular mechanism of sodium ions homeostatic regulation is a mutant CFTR channel that does not have the ability to move chloride ions across the cell membrane. …show more content…
CFTR is a protein channel that serves the apical membrane of the epithelial cell as a chloride ion channel which attracts sodium ion across cell membranes followed by a subsequent flow of water to the cell exterior. ( Shannon Stephen ) In a normal homeostatic regulation of sodium ions level homeostasis is disturbed due to the decrease of sodium level in the extracellular fluid. The granular cells detect the change in blood volume. Therefore, juxtaglomerular apparatus of renal tubules release renin in response to decrease in blood volume. Renin then converts Angiotensin I to angiotensin II. The Angiotensin II then stimulates the release of aldosterone. Finally, aldosterone aids in actively reabsorbing remaining Na+Cl- in distal convoluted tubule by increasing tubule permeability. (Silver Horn ) Therefore promotes both sodium and water reabsorption stopping the original stimulus. This is the whole process of homeostatic regulation of a normal sodium feedback loop that maintains a healthy airway surface