There are a few electrolyte abnormalities: hypokalemia, hypercalcemia, hyperkalemia and hypocalcemia. Hypokalemia is also referred to as low potassium. The main cause is loss of potassium in urine due to diuretic medicines. Diarrhea and vomiting can also contribute to hypokalemia.
The name of the first camera is camera obscura and is described to be the foundation on which most modern cameras are based on. Johann Zahn made the first camera, in 1685.
Philo Farnsworth's Image Dissector was the heart of the first television cameras. This video tells the story of the early days of television, and shows how these early video tubes worked. How analog television works: