First 137 words of the document:
a) Define the terms negative feedback, positive feedback and homeostasis.
b) Explain the principles of homeostasis in terms of receptors, effectors and negative
Internal sensory receptors, for example, temperature receptors or glucose concentration
receptors, are required to monitor conditions inside the body. If they detect a change they
will be stimulated to send a message.
A communication system, such as the nervous system or the hormonal system, is used to
transmit a signal from the receptor cells to the effector cells. This message may or may not
pass through a coordination centre such as the brain.
Effector cells, for example liver cells or muscle cells, are required to bring about a response
that reverses the change detected by the receptor cells.