What are the signs and symptoms for cystic fibrosis?
Cystic fibrosis signs and symptoms vary, depending on the severity of the disease. Even in the same person, symptoms may worsen or improve as time passes. Some people may not experience symptoms until adolescence or adulthood. People with cystic fibrosis have a higher than normal level of salt in their sweat. Parents often can taste the salt when they kiss their children. Most of the other signs and symptoms of cystic fibrosis affect the respiratory system and digestive system. However, adults diagnosed with cystic fibrosis are more likely to have atypical symptoms, such as recurring bouts of inflamed pancreas (pancreatitis), infertility and recurring pneumonia.
What is the renin-aldosterone-angiotensin mechanism?
The renin-angiotensin-aldosterone system (RAAS) plays an important role in regulating blood volume and systemic vascular resistance, which together influence cardiac output and arterial pressure. Renin, which is primarily released by the kidneys, stimulates the formation of angiotensin in blood and tissues, which in turn stimulates the release of aldosterone from the adrenal cortex. Therapeutic manipulation of this pathway is very important in treating hypertension and heart failure. ACE inhibitors, AII receptor blockers and aldosterone receptor blockers, for example, are used to decrease arterial pressure, ventricular afterload, blood volume and hence ventricular preload, as well as inhibit and reverse cardiac and vascular hypertrophy.
What are the differences between eukaryotic cells and prokaryotic cells?
Eukaryotic cells contain membrane-bound organelles, such as the nucleus, while prokaryotic cells do not. Differences in cellular structure of prokaryotes and eukaryotes include the presence of mitochondria and chloroplasts, the cell wall, and the structure of chromosomal DNA. The most fundamental difference is that eukaryotes do have "true" nuclei containing their DNA, whereas the genetic material in prokaryotes is not membrane-bound.