Section 6 - Reflexes Flashcards Preview

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Flashcards in Section 6 - Reflexes Deck (23)
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1

What is a stimulus (1)

- Any change in the internal or external enviornment

2

How does responding to their enviornment help organisms survive (4)

- Animals increase their chances of survival by responding to changes in their external enviornment

- Also respond to changes in their internal enviornment, to make sure the conditions are right for their metabolism

- Plants also increase their chances of survival by responding to changes in their enviornment

- Any change in the internal/external enviornment is called a stimulus

3

Where are receptors found and what is their job (2)

- Sense organs (eyes ears etc)

- Detect external stimuli

4

What are effectors and give two examples of what they do (3)

- Cells that bring about a response to stimuli

- Muscle cells contract

- Glands secrete hormones

5

What are the 3 types of neurone (3)

- Sensory

- Motor

- Relay

6

What does the Central nervous system consist of (2)

- Brain

- Spinal cord

7

When receptors detect a stimulus, what do they do? (1)

- Send electrical impulses along sensory neurones to the CNS

8

What is the CNS's role in a response (3)

- CNS sends electrical impulses to an effector

- Carried by an axon, covered in mylein sheath

- Along a motor neurone

- Effector then responds accordingly

9

Coordinated responses always need a ........ , a ........... and an ........... (3)

- Stimulus

- Receptor

- Effector

10

What is the main job of the CNS (1)

- Coordinate the response

11

What are reflexes (1)

- Automatic responses to certain stimuli

12

After a cupcake candle burns your finger, what happens (1)

- Stimulaton of the pain receptor

13

After your pain receptors are stimulated, what happens (1)

- Impulses travel along sensory neurones

14

After impulses travel along the sensory neurone, what happens (2)

- Impulses are passed along a relay neurone

- Via a synapse

15

What travels along sensory neurones (1)

Impulses

16

After impulses are passed along a relay neurone, via a synapse, what happens (2)

- Impulses travel along a motor neurone

- Via a synapse

17

After impulses travel along a motor neurone via a synapse, what happens (1)

- When impulses reach muscle, it contracts

18

What order do impulses travel along receptors (3)

- Sensory

- Relay

- Motor

19

When a stimulus is detected by receptors, an impulse is sent along a ....... neurone to the ......

- Sensory

- CNS

20

What is the fibre called which carries impulses to the effector (1)

- Axon

21

What is the axon covered in (1)

- Mylelin sheath

22

What are the five steps in the reflex arc (5)

23

What are two purposes of the myelin sheath (2)

- Prevents short circuits with other axons

- Speeds up conduction of impulses