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
Ventricular Arrhythmias. Premature ventricular contractions (PVCs) are the most common cause of irregular heart rhythms. The heartbeat is created by an electrical signal that originates in an area of specialized cells in the heartâs upper right chamber, the right atrium. premature ventricular contraction (PVC) is a too-early heartbeat that originates in the ventricles and disrupts the heartâs normal rhythm.