E1 Stimulus and Response Flashcards Preview

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

Define stimulus

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

2

Define response

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

3

Define reflex

A response that is rapid and involuntary (unconscious)

4

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

Detect stimuli and transform them into electrical nerve impulses

5

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

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

6

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

Transmit nerve impulses within the CNS

7

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

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

8

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

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

9

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

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

10

Explain how hedgehog behaviour has been affected by natural selection

• 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