b3.1

Question 1

What does the nervous system do?

Answer 1

Detects changes in the external environment and sends information to the brain

Question 2

What are the three stages of a nervous response?

Answer 2

Stimulus; sensory receptor; effector

Question 3

How do glands respond to a stimulus?

Answer 3

Release hormones

Question 4

Where are receptor cells found?

Answer 4

Sense organs (eyes, ears, nose, tongue, skin)

Question 5

What do receptor cells do?

Answer 5

Convert stimuli into electrical impulses that travel along neurones to the CNS

Question 6

What is the CNS made of?

Answer 6

Brain and spinal cord

Question 7

How is the spinal cord protected?

Answer 7

By the vertebral column

Question 8

What is the stimulus for skin?

Answer 8

Pressure; heat

Question 9

What is the role of sensory neurones?

Answer 9

Carry electrical impulses from receptor cells to the CNS

Question 10

What is the role of motor neurones?

Answer 10

Carry electrical impulses from the CNS to effectors

Question 11

What is the nervous system made of?

Answer 11

Brain; spinal cord; neurones

Question 12

What are effectors?

Answer 12

Muscles or glands that respond to a change in the environment

Question 13

What are synapses?

Answer 13

Gaps between neurones that allow nerve impulses to pass

Question 14

How do synapses work?

Answer 14

Impulse reaches neurone end; neurotransmitters released; diffuse across synapse; bind to receptors; new impulse generated

Question 15

How do reflex actions help?

Answer 15

Allow rapid and automatic responses to danger

Question 16

Give three examples of reflex actions

Answer 16

Blinking; sneezing; flinching from a hot pan

Question 17

What is a stimulus?

Answer 17

A change in the environment that requires a response

Question 18

Describe the reflex arc

Answer 18

Stimulus detected by receptor; sensory neurone to CNS; motor neurone to effector; response produced

Question 19

What can affect human reaction time?

Answer 19

Caffeine; exercise

Question 20

What is the role of the brain?

Answer 20

Processes information and produces coordinated responses

Question 21

What does the medulla control?

Answer 21

Automatic actions such as breathing rate and heart rate

Question 22

What does the cerebellum control?

Answer 22

Muscle coordination; posture; balance; involuntary movements

Question 23

What is the cerebral cortex?

Answer 23

Outer layer of the cerebrum

Question 24

Why is it hard to treat brain damage?

Answer 24

Limited understanding; risk of irreversible damage

Question 25

What techniques are used in neuroscience?

Answer 25

Studying brain damage; electrical stimulation; MRI scanners

Question 26

Name causes of damage to the PNS or CNS

Answer 26

Injury; disease; genetic conditions; toxic substances

Question 27

What does damaging the nervous system cause?

Answer 27

Prevents impulses passing effectively

Question 28

What are the effects of PNS damage?

Answer 28

Inability to detect pain; numbness; lack of coordination

Question 29

How is PNS damage repaired?

Answer 29

Limited regeneration; surgery for severe damage

Question 30

How can nerve damage be treated surgically?

Answer 30

Grafting nervous tissue to restore conduction

Question 31

Can the CNS regenerate?

Answer 31

No, unless corrected by surgery

Question 32

Why is the spinal cord difficult to repair?

Answer 32

Small diameter; difficult to isolate individual nerve fibres

Question 33

Why is brain interior damage hard to treat?

Answer 33

Difficult to diagnose; limited treatments; high risk

Question 34

What is the function of the optic nerve?

Answer 34

Transmits visual impulses from retina to brain

Question 35

What is the cornea?

Answer 35

Transparent front of eye; refracts light; protects eye

Question 36

What is the sclera?

Answer 36

White, opaque protective outer layer of the eye

Question 37

What is the retina?

Answer 37

Contains receptor cells sensitive to brightness and colour

Question 38

What is the pupil?

Answer 38

Hole in centre of iris that lets light into eye

Question 39

What does the iris do?

Answer 39

Controls pupil size and light entering the retina

Question 40

What are ciliary muscles?

Answer 40

Ring of muscle that changes lens shape

Question 41

What are suspensory ligaments?

Answer 41

Fibres connecting ciliary muscles to lens

Question 42

What is accommodation?

Answer 42

Changing lens shape to focus on objects at different distances

Question 43

What happens when focusing on a distant object?

Answer 43

Ciliary muscles relax; suspensory ligaments tighten; lens flattens

Question 44

What controls adaptation to different light levels?

Answer 44

Iris

Question 45

What is hyperopia and its treatment?

Answer 45

Long-sightedness; convex lens

Question 46

What is myopia and its treatment?

Answer 46

Short-sightedness; concave lens

Question 47

What causes colour blindness?

Answer 47

Defective photoreceptors

Question 48

What happens when focusing on a close object?

Answer 48

Ciliary muscles contract; suspensory ligaments loosen

Question 49

What happens to the lens with age and why?

Answer 49

Lens less flexible; cannot fatten; image behind retina

Question 50

What is a CT scan?

Answer 50

Uses X-rays to produce 3D images; shows still images

Question 51

What is MRI scanning?

Answer 51

Uses magnets to identify brain abnormalities and active areas

Question 52

What is fMRI scanning?

Answer 52

Real-time images showing active brain areas via blood flow

Question 53

How does electrical stimulation work?

Answer 53

Electrodes stimulate brain tissue causing movement

Question 54

What does the cerebrum control?

Answer 54

Memory; learning; personality; conscious thought

Question 55

How do muscles respond to impulses?

Answer 55

Contract

Question 56

What are skin receptor stimuli?

Answer 56

Pressure; temperature

Question 57

What are nose receptor stimuli?

Answer 57

Chemicals

Question 58

What do relay neurones do?

Answer 58

Transmit impulses between sensory and motor neurones

Question 59

What are nerves?

Answer 59

Bundles of neurones

Question 60

Steps of a nervous reaction

Answer 60

Stimulus; receptor; sensory neurone; spinal cord; brain; motor neurone; effector; response

Question 61

Examples of reflex actions controlling vital functions

Answer 61

Breathing; heart rate; digestion

Question 62

Describe the reflex arc

Answer 62

Stimulus; receptor; sensory neurone; spinal cord; motor neurone; effector; response

Question 63

Describe the lens

Answer 63

Transparent biconvex structure

Question 64

Describe the optic nerve

Answer 64

Nervous tissue carrying impulses to brain

Question 65

Why have a central control centre?

Answer 65

Faster communication than spread control

Question 66

What does the hypothalamus regulate?

Answer 66

Temperature and water balance

Question 67

What does the pituitary gland do?

Answer 67

Stores and releases hormones

Question 68

What is the PNS?

Answer 68

Neurones connecting CNS to rest of body

Question 69

Effects of CNS damage

Answer 69

Loss of control; paralysis; memory and processing problems

Question 70

Treatments for brain damage

Answer 70

Radiotherapy; chemotherapy; surgery; deep brain stimulation

Question 71

What are Schwann cells?

Answer 71

Myelin sheath insulating axons

Question 72

Where are relay neurones found?

Answer 72

Only in the CNS during reflexes

Question 73

What is the function of the conjunctiva?

Answer 73

Protects eye from infection

Question 74

What is an axon?

Answer 74

Carries impulses away from cell body

Question 75

What is a dendron?

Answer 75

Carries impulses toward the cell body

Question 76

How do eyes adjust to light levels?

Answer 76

Radial and circular muscles change pupil size

Question 77

Describe accommodation in detail

Answer 77

Near: ciliary muscles contract, ligaments slacken, lens thickens; Far: ciliary muscles relax, ligaments tighten, lens thins

Question 78

Sensory neurone – definition

Answer 78

A type of neurone that carries electrical impulses from sensory receptors towards the central nervous system (CNS)

Question 79

Motor neurone – definition

Answer 79

A type of neurone that carries electrical impulses from the CNS to effectors such as muscles or glands

Question 80

Reaction time value

Answer 80

Average human reaction time is approximately 0.7 seconds

Question 81

Reflex arc – speed explanation

Answer 81

Reflex arcs are faster than conscious pathways because impulses only pass through the spinal cord and not the brain

Question 82

Aqueous humour

Answer 82

Transparent fluid in the front part of the eye that provides nutrients and maintains pressure

Question 83

Choroid

Answer 83

Layer of the eye that provides nutrients and removes waste from the retina

Question 84

Optic nerve head

Answer 84

Point where nerve fibres leave the eye; also known as the blind spot

Question 85

Sensory neurone – role

Answer 85

Carries impulses from receptors to CNS

Question 86

Motor neurone – role

Answer 86

Carries impulses from CNS to effectors (muscles or glands)