A reflex test of the knee is the basis for the term knee-jerk reaction.. A knee-jerk reaction is typically impulsive in nature and doesn't allow for someone to think things through. An outburst of anger is an example of a knee-jerk reaction.
As Figure 1 shows, the central processing unit consists of two parts: The control unit and the arithmetic/logic unit. Each part has a specific function. Before we discuss the control unit and the arithmetic/logic unit in detail, we need to consider data storage and its relationship to the central processing unit.
1. central processing unit - (computer science) the part of a computer (a microprocessor chip) that does most of the data processing; the CPU and the memory form the central part of a computer to which the peripherals are attached.C.P.U. , central processor, CPU, mainframe, processor.entral processing unit. n. 1. (Computer Science) the part of a computer that performs logical and arithmetical operations on the data as specified in the instructions.