B6 - Brain and Mind Flashcards
(103 cards)
1
Q
What is a stimulus?
A
A change in an organism’s environment
2
Q
Why do animals respond to stimuli?
A
In order to keep themselves in suitable conditions for survival
3
Q
How is an animal’s response to stimuli co-ordinated?
A
By the central nervous system (CNS)
4
Q
What does CNS stand for?
A
Central nervous system
5
Q
What is the part of the CNS that co-ordinates a response to stimuli called?
A
The processing centre
6
Q
How is the CNS (brain and spinal cord) connected to the rest of the body?
A
Peripheral nervous system (PNS)
7
Q
What does PNS stand for?
A
Peripheral nervous system
8
Q
What does the peripheral nervous system consist of? (2 things)
A
- Sensory neurons that carry impulses from receptors to the CNS
- Motor neurons that carry impulses from the CNS to effectors
9
Q
What 2 things can form part of complex organs?
A
Receptors and effectors
10
Q
Receptors and effectors can form part of complex organs such as?
A
- Muscle cells in a muscle
- Light receptor cells in the retina of the eye
- Hormone secreting cells in a gland
11
Q
How do muscle cells in a muscle work?
A
Impulses travel along motor neurons and stop at the muscle cells (effectors), causing the muscle cells to contract
12
Q
How do light receptor cells in the retina of the eye work?
A
The lens focuses light onto receptor cells in the retina. The receptor cells are then stimulated and send impulses along sensory neurons to the brain.
13
Q
How do hormone secreting cells in a gland work?
A
An impulse travels along a motor neuron and stops at the hormone secreting cells in glands (effectors). This triggers the release of the hormone into the bloodstream.
14
Q
What are neurons?
A
Specially adapted cells that carry an electrical signal when stimulated
15
Q
Why are neurons elongated (lengthened)?
A
To make connections between different parts of your body
16
Q
To make connections between different parts of your body, what is the structure of a neuron like?
A
They are elongated (lengthened)
17
Q
Why do neurons have branched endings?
A
So that a single neuron can act on many other neurons or effectors
18
Q
So that a single neuron can act on many other neurons or effectors, what is the structure of a neuron like?
A
They have branched endings
19
Q
What does the cytoplasm form in motor neurons?
A
It forms a long fibre surrounded by a cell membrane called an axon
20
Q
What is an axon?
A
The thread-like extension of a nerve cell
21
Q
What are some axons surrounded by?
A
A fatty sheath
22
Q
What does the fatty sheath do for some axons? (2 things)
A
- Insulates the neuron from neighbouring cells
- Increases the speed at which the nerve impulse is transmitted
23
Q
What are synapses?
A
Gaps between adjacent neurons
24
Q
How are impulses transferred between neurons? (HT)
A
1) A nerve impulse reaches the synapse through the sensory neuron
2) The impulse triggers the release of chemicals, called neurotransmitters, into the synapse
3) Neurotransmitters diffuse across the synapse and bind with receptor molecules on the membrane of a motor neuron
4) A nerve impulse is sent through the motor neuron
The receptor molecules only bind with certain chemicals to start a nerve impulse in the motor neuron.
25
What is a reflex action?
A fast, automatic, involuntary response to a stimulus.
26
Explain the basic pathway for a reflex arc.
1) A receptor is stimulated (e.g. by a sharp pain)
2) This causes impulses to pass along a sensory neuron into the spinal cord
3) The sensory neuron synapses with a motor neuron, sending impulses to the effectors
4) The relay neuron synapses with a motor neuron, sending impulses to the effectors.
5) The effectors respond (e.g. muscle contract).
27
What do simple reflexes like the reflex arc ensure?
That an animal automatically responds to a stimulus in a way that helps it to survive; for example finding food, sheltering from predators, finding a mate
28
The fixed pathway of neurons in these actions allows what? (HT)
A very rapid response - there isn't any processing of the information by the brain.
29
The majority of the behaviour displayed by simple animals is the result of what?
Reflex actions
30
What is the disadvantage of the majority of the behaviour displayed by simple animals being the result of reflex actions?
The animals have difficulty responding to new situations
31
Name 4 examples of how newborn babies exhibit a range of simple reflexes?
- Stepping reflex
- Grasping reflex
- Rooting reflex
- Sucking reflex
32
Explain the stepping reflex that newborn babies show.
When held under its arms in an upright position, with feet on a firm surface, a baby makes walking movements with its legs
33
Explain the grasping reflex that newborn babies show.
Baby tightly grasps a finger that is placed in its hand
34
Explain the rooting reflex that newborn babies show.
Baby turns its head and opens mouth ready to feed when its cheek is stroked.
35
Explain the sucking reflex that newborn babies show.
Baby sucks on a finger (or mother's nipple) that is put in its mouth
36
True or False?
Adults do not show simple reflexes like newborn babies do.
False - adults also display a range of simple reflexes.
37
Give some examples of how adults can also display simple reflexes.
- The pupil reflex in your eye stops bright light from damaging your retina. Your iris controls the amount of light that enters your eye by contracting various muscle fibres.
- The 'knee-jerk' when the leg straightens if the knee joint is struck beneath the knee cap
- Dropping a hot object when you grip it
- Blinking when an object comes close to your face
38
What are 3 features of a simple adult reflex when dim light affects an eye.
- Increased pupil size
- Radial muscles contract
- Circular muscles relax
39
What are 3 features of a simple adult reflex when bright light affects an eye.
- Decreased pupil size
- Radial muscles relax
- Circular muscles contract
40
Explain the pupil reflex stage-by-stage.
- Light on retina
- Impulse via optic nerve to the brain
- Impulse via motor nerve to iris muscles
- Pupil changes size
41
How are reflex responses to new stimuli learned?
By building an association between the stimulus that naturally triggers the response (primary stimulus) and the new stimulus (secondary stimulus)
42
What is a reflex action brought about by a learned stimulus called?
A conditioned reflex action.
43
What is a conditioned reflex action?
A reflex action brought about by a learned stimulus
44
Who discovered the idea of a conditioned reflex action?
A Russian scientist named Pavlov
45
When did Russian scientist Pavlov discover the idea of conditioned reflex actions?
Early 20th Century
46
What experiment did Pavlov carry out to prove his theory about conditioned reflex actions?
A dog experiment
- A bell was rung repeatedly whenever meat was shown and given to the dog
- Eventually, ringing the bell without any meat present caused the dog to salivate
47
How can somebody feeling hungry just by looking at a clock be a further example of a conditioned reflex action?
That person has been conditioned to feel hungry at that time, even if you're not actually hungry
48
True or False?
In a conditioned reflex, the final response has many connections to the reflex. (HT)
False - In a conditioned reflex, the final response has no direct connection to the stimulus.
49
True or False?
Some conditioned reflexes can increase a species' chance of survival. (HT)
True
50
Give an example of how a conditioned reflex can increase a species' chance of survival. (HT)
The caterpillar of the cinnabar moth is black and orange in colour, to warn predators that it's poisonous. After eating a few cinnabar caterpillars, a bird will start to associate these colours with with a very unpleasant taste and avoid eating anything that is black and orange in colour. In this way, a conditioned reflex may be regarded as simple learning.
51
In some situations, how can your brain override/modify a reflex action? (HT)
By sending a signal via. a neuron to the motor neuron in the reflex arc.
52
Your brain can override a reflex action by sending a signal to the motor neuron in the reflex arc. Give an example of this modification. (HT)
This modification allows you to keep hold of a hot plate even though your body's natural reflex response it to drop it.
53
What type of neuron carries impulses from the central nervous system to an effector such as a muscle?
Motor neuron
54
What is the name of the long fibre attached to the cell body in a motor neuron?
Axon
55
What is the name given to the type of action when the final response has no direct connection to the stimulus?
Conditioned reflex action
56
What makes mammals brains 'complex'?
They contain billions of neurons
57
What do the millions of neurons in the complex brain of mammals allow them to do?
Learn from experience, including how to respond to different situations (social behaviour)
58
What is formed in the brain during development of mammals?
Neuron pathways
59
The brain grows ___a)___ during the first few years after birth. As each neuron matures, it sends out multiple ___b)___, increasing the number of ___c)___.
a) rapidly
b) branches
c) synapses
60
The way in which a mammal interacts with its environment determines which pathways are formed. Explain this process.
1) Each time you have a new experience, a different neuron pathway is stimulated
2) Every time the experience is repeated after that, the pathway is strengthened
3) Pathways that aren't used regularly are eventually deleted.
4) Only the pathways that are activated most frequently are preserved.
61
What do modifications mean about certain pathways of your brain?
They are more likely to transmit impulses than others and you will learn how to do a task.
62
How are humans able to learn some things by repetition (e.g. riding a bike, revising for an exam or learning an instrument)?
Because modifications mean that certain pathways of your brain are more likely to transmit impulses than others and you will learn how to do a task.
63
What does a PET scan stand for?
Positron Emission Tomography scan
64
What can a PET scan do?
Provide a 3D image which show neuron activity in parts of the brain in response to learning words through:
- hearing them
- seeing them
- speaking them
65
True or False?
The areas that are stimulated the most develop less synapses between neurons.
False - The areas that are stimulated the most develop more synapses between neurons.
66
After children are born, there are a series of developmental milestones that can be check to see if development is following normal patterns.
If the milestones are missing or late, what could it mean? (2 things) [HT]
- There are neurological problems
| - The child is lacking stimulation
67
Give some examples of developmental milestones in young children. (HT)
- At 3 months, babies should be able to lift their heads when held to someone's shoulder
- At 12 months, babies should be able to hold a cup and drink from it
68
What is meant by the term 'feral children'? (HT)
Feral children have been isolated from society in some way, so they don't go through the normal developmental process.
69
In what ways can feral children be isolated from society? (HT)
- Deliberate isolation (when a child is deliberately isolated from society, e.g. in a locked room)
- Accidental isolation (when a child is accidentally isolated from society, e.g. through being shipwrecked)
70
Why might a child be feral? (HT)
In the absence of any other human, the children don't ever gain the ability to talk, other than to make rudimentary grunting noises
71
True or False?
Learning a language later in development is a much harder and slower process. (HT)
True.
72
Evidence suggests that children only learn some skills at particular stages in their development. Give one example of evidence. (HT)
One example of evidence showing this comes from the study of language development in 'feral children'.
73
The variety of potential pathways in the brain makes it possible for animals to do what? (HT)
Adapt to new situations
74
Give some examples of how animals can adapt to new situations (due to a variety of potential pathways in the brain). (HT)
- Dogs can be trained to follow spoken commands
| - Dolphins in captivity can be trained to collect food from a person's hand
75
What gave humans a better chance of survival?
The evolution of a large brain containing billions of neurons, due to the ability to arrive at complex conclusions quickly in different situations.
76
What are some of the skills that enable human survival?
- Intelligence
- Memory
- Language
- Consciousness (a sense of right or wrong)
77
Where are skills that enable human survival (such as intelligence, memory, language and consciousness) dealt with?
The cerebral cortex area of the brain
78
Give 3 examples of how scientists have used different methods to map the regions of the cerebral cortex.
- Physiological techniques
- Electronic techniques
- Magnetic Resonance Images (MRI) scanning
79
What does MRI stand for?
Magnetic Resonance Images
80
Explain how scientists have used physiological techniques to map the regions of the cerebral cortex.
Damage to different parts of the brain can produce different problems, e.g. memory loss, paralysis or speech loss. Studying the effects of this has lef to an understanding of which parts of this brain control different functions.
81
Explain how scientists have used electronic techniques to map the regions of the cerebral cortex.
An electroencephalogram (EEG) is a visual record of the electrical activity generated by neurons in the brain. Electrodes are placed on the scalp to pick up the electrical signals. By stimulating the patient's receptors, the parts of the brain that respond can be mapped.
82
What does EEG stand for?
electroencephalogram
83
Explain how scientists have used MRI scanning to map the regions of the cerebral cortex.
This is a relatively new technique that can be used to produce images of different cross-sections of the brain. The computer-generated picture uses colour to represent different levels of electrical activity. The activity in the brain changes depending on what the person is doing or thinking.
84
What is memory?
The ability to store and retrieve information.
85
Describe the two types of memory.
- Short term memory = stores information for a limited period of time
- Long term memory = stores an unlimited amount of information
86
Many scientists have produced models to try to explain how the brain stores information.
What is an example of these models?
The multi-store model, which states that short-term memory can be rehearsed so that it enters long-term storage.
87
Explain the multi-store model.
The idea that short-term memory can be rehearsed so that it enters long-term storage.
88
What is the problem with the multi-store model used by scientists to try and explain how the brain stores information?
It doesn't fully explain memory, as it's been found that information doesn't need short-term rehearsal to be stored as long-term memory.
It also doesn't explain why human forget
89
Why might humans forget information? (2 reasons)
- Physical (neurons decaying, e.g. in Alzheimer's disease)
| - Lack of retrieval (if we don't use the information for a long time, the pathway is lost)
90
Give some ways in which a person is more likely to remember information.
- If it's repeated (especially over an extended period of time)
- If there's a strong stimulus associated with it (e.g. colour, light, smell or sound)
- You can see a pattern in it or impose a pattern on it (e.g. the order of the planets can be remembered by imposing a pattern -- "Mr Venus' elephant makes jam sitting upon nectarines" = Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune)
91
Name some drugs or toxins that can affect the nervous system.
Ecstasy, beta blockers, prozac
92
How can drugs and toxins (such as ecstacy, beta blockers and prozac) affect the nervous system?
By changing the speed at which nerve impulses travel to the brain.
93
Other than affecting the nervous system (by changing the speed at which nerve impulses travel to the brain), how else can drugs and toxins affect the nervous system?
- Send false signals to the brain
- Prevent nerve impulses from travelling across synapses
- Overload the nervous system with too many nerve impulses
94
What is serotonin? (HT)
A chemical transmitter used in the central nervous system. It can have mood-enhancing effects, i.e. it's associated with feeling happy.
95
Where does serotonin pass through the brain? (HT)
Passes across the brain's synapses, landing on receptor molecules.
96
What happens to serotonin not on a receptor? (HT)
It is absorbed back into the transmitting neuron by the transporter molecules.
97
What is Ecstasy also known as? (HT)
MDMA
98
How does ecstasy affect synapses? (HT)
It blocks the transporter sites causing serotonin to build up in the synapse which causes
- Serotonin concentrations in the brain to increase
- The user to experience feelings of elation
99
Why is ecstasy so dangerous? (HT)
Because neurons are harmed in the process of synapse build ups (due to the transporter sites being blocked) and memory loss can be caused in the long term.
100
What is needed before biologists will accept a new theory on memory? (3 things)
- Have a scientific mechanism
- be published
- Be repeatable
101
Describe the sequence of nerve impulse transmission. (HT)
- Nerve impulse moves through sensory neuron
- Chemical neurotransmitters are released into synapse
- Neurotransmitters diffuse across
- Neurotransmitters bind with receptors on motor neuron
- Nerve impulse is sent through motor neuron
102
What does a motor neuron do to a hormone secreting gland when a message is sent?
It causes the gland to release a hormone into the blood
103
Raul picks up a plate with his dinner on it and immidiately drops it because it's far too hot. This is an example of a reflex action.
Explain as fully as you can the sequence of events that take place in Raul's nervous system for this to happen.
When Raul picks up the plate, receptors in his skin will be stimulated to set up an impulse in a sensory neuron. This impulse will move across a synapse to set up an impulse in a motor neuron. This impulse will pass to muscles in his arm, causing contraction, resulting in him moving his fingers to release the hot plate. (Neurotransmitters also diffuse across the synapse)
