An organelle is a specialized cellular structure in eukaryotic cells analogous to an organ in the body.Organelles are discrete structures within the cell that perform a specialized function. Most are surrounded by internal membranes and can be seen in the light or the electron microscope.n organelle is a specialized cellular structure in eukaryotic cells analogous to an organ in the body.
irregular pulse or heart palpitations; chest pain; pale skin; sweating; What causes abnormal heart rhythms? A number of things may cause an abnormal heartbeat, including high blood pressure. Other common causes are: Coronary heart disease. This serious heart problem occurs when cholesterol and other deposits block the coronary arteries. Medications
Atrial fibrillation -- the most common type of cardiac arrhythmia -- causes an irregular heartbeat that can increase your risk for stroke and heart failure. Atrial fibrillation (AF or AFib) results from faulty signals produced by the heart's electrical system, causing the upper portion of the heart to fibrillate, or contract rapidly and irregularly.