Negative feedback system
In negative feedback the system is always on, generating a product. Once a certain level of product is attained, or an inhibitor enters the system, this stimulus is observed by receptors that then transmit a signal from the control centre back to the control centre notifying its effectors to shut the system down. The system then shuts down until the stimulus is removed and the receptors stop transmitting a signal to the control centre. Negative feedback controls the rate of a process to avoid accumulation of a product, this is essential for homeostasis.
Feedforward System
A feedforward system reacts to changes within its environment, typically to maintain some form of equilibrium. The information is sent ahead of time to prepare a part of a control system. The effector system is activated before any change has taken place, by anticipating change the environment is in a prolonged state of readiness.
Positive Feedback System
Positive feedback occurs when the rate of a process increases as the concentration of the product increases. The rate of a process will continuously increase as long as substrate is available and the product is not used by some other process. Ultimately positive feedback results in an explosive growth and can only be stopped when a limit is reached (e.g. contractions in childbirth).
Was looking for any feedback on my descriptions of the general principles of the above.
Thanks