E1 Stimulus and Response Flashcards Preview

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Flashcards in E1 Stimulus and Response Deck (10)
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1
Q

Define stimulus

A

A change in the environment (external or internal) that is detected by a receptor and elicits a response

2
Q

Define response

A

A change in an organism (an action) resulting from a stimulus

3
Q

Define reflex

A

A response that is rapid and involuntary (unconscious)

4
Q

Describe the role of receptors in the response of animals to stimuli

A

Detect stimuli and transform them into electrical nerve impulses

5
Q

Describe the role of sensory neurons in the response of animals to stimuli

A

Relay the nerve impulse to the central nervous system (via the dorsal root of the spinal cord)

6
Q

Describe the role of relay neurons in the response of animals to stimuli

A

Transmit nerve impulses within the CNS

7
Q

Describe the role of motor neurons in the response of animals to stimuli

A

Receive nerve impulses from the CNS (via the ventral root) and relays the signal to an effector

8
Q

Describe the role of effectors in the response of animals to stimuli

A

Produce a response to the stimulus (can be muscles or glands)

9
Q

Describe the role of synapses in the response of animals to stimuli

A

The junctions between two nerve cells and transmission of a signal across these junctions require chemical neurotransmitters

10
Q

Explain how hedgehog behaviour has been affected by natural selection

A
  • Hedgehogs exhibit different self-defensive responses to danger across different populations: curing into a ball to expose spines which create a shield for skin body and limbs, or running away
    • In areas where there are vehicles and roads, hedgehogs that run away when faced with danger (oncoming vehicles) will be favoured over ones which curl into a ball, as the spines will not protect against oncoming vehicles
    • Thus hedgehogs which run away are selected for by the environment