Glossary

Question 1

Stimulus

Answer 1

• Detectable change in the internal or external environment
  eg/ loud bang or a perfume smell
• Prompts a change in the organism

Question 2

Receptor

Answer 2

• Cell that is adapted to detect changes in the environment
  eg/ photoreceptor or chemoreceptor
• Specific to a type of stimulus

Question 3

Response

Answer 3

• Change in an organism as a reduction to a stimulus.
  eg/ Foot lift or pupil dilation
• Organisms ability to do this is a life characteristic
• increases an organisms chance of survival

Question 4

Effector

Answer 4

• Organ (usually a muscle or gland) that responds to stimulation by a nerve impulse
  = Response
  eg/ Salivary gland = saliva in response to smelling food

Question 5

Co-ordinator

Answer 5

• Connects the information from each receptor with the appropriate effector
• Acts like a switchboard = correct response

Question 6

Negative feedback

Answer 6

• Series of changes, important in homeostasis
  = Substance being restored to its normal level
  Eg/ Process of thermoregulation

Question 7

Positive feedback

Answer 7

• Results in a substance that departs from its normal level, becoming further from its normal level
  Eg/ corrective measures remain turned on.

Eg/ Production of oxytocin during child birth.