Sensory reception

• Effectors are a range of cells/tissues/organs that carry out a response
• Stimuli are detectable changes in the internal or external environment
• Receptors are cells/organs that detect specific stimuli
• Kinesis is a random non-directional response to an unpleasant stimuli
• A coordinator is an intermediary between a receptor and effectors which formulates a suitable response to a stimulus
• Taxis is a directional response to a stimuli
• Basic sequence of a response arc

  stimulus -> receptor -> coordinator -> effector -> response
• The direction of taxis is determined by the direction of the stimuli. Positive taxis is towards a stimulus, negative taxis is away from a stimulus
• Kinesis involves the frequent changes in speed of movement and rate at which it changes direction
• Responding to stimuli increases the chances of an organism finding or staying in favourable conditions