b6.2

Question 1

1. What are nervous systems made up of?

Answer 1

-neurons (nerve cells) linking receptor cells (e.g. in eyes, ears and skin) to effector cells (in muscles/glands)

Question 2

2. What do neurons do when stimulated?

Answer 2

-neurons transmit electrical impulses when stimulated

Question 3

3. What is an axon?

Answer 3

-an axon is a long extension of the cytoplasm in a neuron and is surrounded by a cell membrane

Question 4

4. What are some axons surrounded by and why?

Answer 4

-some axons are surrounded by a fatty sheath, which insulates the neuron from neighbouring cells and increases the speed of transmission of a nerve impulse

Question 5

5. What does CNS stand for?

Answer 5

-central nervous system

Question 6

5. What are vertebrates?

Answer 6

-animals with backbones

Question 7

5. What is the central nervous system (CNS) made up of in humans and other vertebrates?

Answer 7

-only the spinal cord and brain

Question 8

6. What is the central nervous system (CNS) in mammalians (mammals)?

Answer 8

-in the mammalian nervous system the CNS (brain and spinal cord) is connected to the body via the peripheral nervous system (PNS) (sensory and motor neurons)

Question 9

6. What is the PNS?

Answer 9

• peripheral nervous system
• sensory and motor neurons
• connects CNS to body in mammals

Question 10

7. How does the CNS coordinate an animal’s responses?

Answer 10

• sensory neurons carry impulses from receptors to the CNS

- motor neurons carry impulses from the CNS to effectors

Question 11

7. What do sensory neurons do?

Answer 11

carry impulses from receptors to the CNS

Question 12

7. What do motor neurons do?

Answer 12

carry impulses from the CNS to effectors

Question 13

8. What happens to impulses within the CNS?

Answer 13

-within the CNS, impulses are passed from sensory neurons to motor neurons through relay neurons

Question 14

9. What is in the nervous pathway of a spinal reflex arc?

Answer 14

receptor, sensory neuron, relay neuron, spinal cord, motor neuron and effector

Question 15

9. What do receptors do?

Answer 15

-detect stimuli

Question 16

9. What are examples of receptors?

Answer 16

• taste in tongue
• sound in ears
• light in retina

Question 17

9. What do effectors do?

Answer 17

-respond to nervous impulses and bring about change

Question 18

9. What are examples of effectors?

Answer 18

• muscle cells in muscles

- hormone secreting cells in glands

Question 19

10. How are neurons arranged and what does this mean?

Answer 19

-neurons are arranged into a fixed pathway which allows reflex responses to be automatic and so very rapid, since no processing of information is required

Question 20

11. What are synapses?

Answer 20

• the gaps between adjacent neurons

- impulses are transmitted across them

Question 21

12. What happens at a synapse?

Answer 21

-an impulse triggers the release of chemicals (transmitter substances) from the first neuron into the synapse, which diffuse across and bind to receptor molecules on the membrane of the next neuron

Question 22

13. What happens to transmitter chemicals at neurons?

Answer 22

-only specific chemicals bind to the receptor molecules, initiating a nerve impulse in the next neuron

Question 23

14. What are examples substances that can affect the transmission of impulses across synapses?

Answer 23

• toxins

- drugs like: ecstasy, beta blockers and Prozac

Question 24

14. What can drugs like ecstasy, beta blockers and Prozac and toxins do to synapses?

Answer 24

-they can affect the transmission of impulses across synapses

Question 25

15. What is ecstasy also known as?

Answer 25

-MDMA

Question 26

15. What is MDMA?

Answer 26

-ecstasy

Question 27

15. How does Ecstasy (MDMA) affect synapses?

Answer 27

-it blocks the sites in the brain’s synapses where the transmitter substance, serotonin, is removed

Question 28

16. What does serotonin effect?

Answer 28

-pain, aggression, appetite, mood

Question 29

16. What effects does ecstasy have?

Answer 29

-Mood-enhancing effects

Question 30

16. What causes the effects of Ecstasy on the nervous system?

Answer 30

-the subsequent increase in serotonin concentration, as it cannot be removed

Question 31

17. What is the part of the brain most concerned with intelligence, memory, language and consciousness?

Answer 31

-cerebral cortex

Question 32

17. What is the cerebral cortex?

Answer 32

-the part of our brain most concerned with intelligence, memory, language and consciousness

Question 33

18. How do scientists map the regions of the brain to particular functions?

Answer 33

- studies of patients with brain damage - studies in which different parts of the brain are stimulated electrically - brain scans such as MRI

Question 34

18. How do studies of patients with brain damage help scientists map the regions of the brain to particular functions?

Answer 34

- study what small damaged part stops a person from doing

Question 35

18. How do studies in which different parts of the brain are stimulated electrically help scientists map the regions of the brain to particular functions?

Answer 35

-small electrode pushed into the tissue and giving it electricity= stimulates it so can see what it does

Question 36

18. How do brain scans such as MRI help scientists map the regions of the brain to particular functions?

Answer 36

-produces detained picture of brains structure= can see which parts are active when doing things

Question 37

18. What does MRI scanner stand for?

Answer 37

-magnetic resonance imaging scanner