Vitamin A deficiency: Related Medical Conditions. To research the causes of Vitamin A deficiency, consider researching the causes of these these diseases that may be similar, or associated with Vitamin A deficiency:
Definition of push button. : a small button or knob that when pushed operates something especially by closing an electric circuit.
The most common type is a push-to-make (or normally-open or NO) switch, which makes contact when the button is pressed and breaks when the button is released. Each key of a computer keyboard, for example, is a normally-open push-to-make switch.