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
Quick Answer. There are a number causes of an irregular heartbeat, including eating disorders, bulimia nervosa, atrial fibrillation, thyrotoxicosis, mitral valve prolapse and heart problems, according to Right Diagnosis. Uncommon causes include sickle cell anemia, scleroderma and chronic fatigue syndrome.