Brain and Behaviour Flashcards
(110 cards)
1
Q
What two things are the nervous systems made up of?
A
Neurons and glial cells
2
Q
What is the definition of a neuron?
A
Functional building blocks of nervous system – cells which transmit electrical activity which underlies psychological processes
3
Q
What is the definition of a glial cell – name three of it functions in the definition?
A
Cells surrounding the neurons holding them in place, providing nutrients and isolating toxins that would harm the neuron
4
Q
How many neurons in an average human brain?
A
86 million neurons
5
Q
What are neurons connected by?
A
A synapse
6
Q
Define a synaptic cleft/space
A
A tiny gap between the axon terminal and the next neuron (the pre-synaptic neurons send messages and the post-synaptic neurons receive messages)
7
Q
Define a sensory neuron
A
Carry input messages from the sense organ to the spinal cord and the brain
8
Q
Define a motor neuron
A
Transmit output impulses from brain and spinal cord to the body’s muscles and organs
9
Q
Define an inter-neuron
A
Perform connective or associative functions within the nervous system – these outnumber sensory and motor neurons
10
Q
Define the peripheral nervous system
A
Contain all the neural structures that lie outside of the brain and the spinal cord
11
Q
What two functions does the PNS perform? (one is sensory input and the other motor output)
A
- Sensory input functions that enable us to sense what’s going on inside and outside of our bodies
- Motor output function that enable us to respond with our muscles and glands
12
Q
What are the two subdivisions of the PNS, and define them
A
• Somatic nervous system – a system of sensory and motor neurons that allow us to sense and respond to our environment
• Autonomic nervous system – senses the body’s internal functions and controls the glands and the involuntary muscles that form the heart, blood vessels and lining of the stomach and intestines
o Involved in respiration, digestion, circulation, motivation, emotional behaviour and stress responses
13
Q
Name and define the two subdivisions of the ANS
A
• Sympathetic nervous system – has an activation or arousal function and tends to act as a total unit –
o Flight or fight response
o When you encounter a stressor your sympathetic nervous system helps you in a number of ways e.g. speeds heartrate, dilates pupils, slows digestion
• Parasympathetic nervous system – slows down the body processes and maintain a sense of tranquillity
o Slows down heart rate, allows digestion, contracts pupils
14
Q
What is homeostasis?
A
A delicately balanced or constant internal state
15
Q
Define the central nervous system
A
Contains the brain and the spinal cord, which connects most parts of the peripheral nervous system with the brain
16
Q
What is it called when a response is triggered without the involvement of the brain and give an example of it
A
A spinal reflex or simple withdrawal reflex – touching a hot plate and dropping it immediately – by bypassing the brain there is a reduction of potential tissue damage
17
Q
Name the three main parts of a neuron – and define each part
A
o Cell body – also known as soma – contain biochemical structures needed to keep the neuron alive, and its nucleus carries the genetic information that determine how the cell develops and functions
o Dendrite – branch-like structure protruding from the cell body – specialised receiving unit like antennae that collect messages from neighbouring neurons and send them onto the cell body
o Axons – extends from one side of the cell body – conducts electrical impulses away from the cell body to the other neurons, muscles or glands
18
Q
What are all neurons covered by and what does it do?
A
Cell membrane – controls the exchange of chemical substances between the inside and outside of the cell
19
Q
Name the three stages of electrical activity of neurons
A
Resting potential -> action potential -> resting potential
20
Q
Explain what resting potential is – mention polarization
A
When neuron isn’t involved in creating impulses – when inner ions are more negatively charged than outer ions, so a net negative charge (this is polarization)
21
Q
Explain what action potential is – mention depolarization
A
An electrical shift occurs when the neuron is stimulated and positive sodium ions enter the neuron, this causes a brief moment of depolarization
22
Q
What happens after an impulse?
A
A recovery period called absolute refractory period – a period during which the membrane is not excitable and cannot discharge another impulse
23
Q
What is the limit of human impulses (per second)
A
300 pulses per second
24
Q
Explain the concept ‘All or nothing’
A
The fact that action potential can either occur at a uniform maximum or not at all – the electrical stimulation needs to meet a certain intensity or the neuron will not fire
25
What is a graded potential?
Changes in the negative resting potential that do not reach the action potential threshold – sometimes graded potential add up and trigger an action potential
26
Define myelin sheath
A whitish fatty insulation layer derived from glial cells during development
27
What are nodes of Ranvier?
Interruptions in the myelin sheath – they are at regular intervals and speed up transmission
28
Is myelin sheath present at birth?
It isn’t completely formed at birth, fully developed sometime in later childhood
29
Name a disorder that damage to the myelin sheath can cause – name the symptoms
Multiple sclerosis – when individual’s own immune system attacks the myelin sheath – disrupts the timing of nerve impulses to muscles – results in jerky and unco-ordinated movements and the paralysis
30
What is a neurotransmitter?
Chemical substance that carry messages across the synaptic cleft to other neuron, muscles or glands
31
Name the 5 steps of communication of a neurotransmitter and expand on each step
I. Synthesis – transmitter molecules formed inside neuron
II. Storage – molecules are stored in synaptic vesicles (chambers within the axon terminal)
III. Release – action potential causes the vesicles to move to the surface of axon terminal and release molecules into synaptic cleft between presynaptic and postsynaptic neuron
IV. Binding – transmitter molecules bind themselves to receptor sites – each neurotransmitter fits like a lock and key
V. Deactivation – a neurotransmitter molecule continues to excite or inhibit a neuron until deactivated
32
Name two ways deactivation can occur
o The neurotransmitter broken down by other chemicals
| o Re-uptake so the neurotransmitter molecules are taken back into the presynaptic terminal
33
Explain excitatory neurotransmitters
A neurotransmitter that causes the action potential to fire
34
Explain inhibitory neurotransmitters
A neurotransmitter that prevents the neuron from firing
35
Give an example of a neurotransmitter
Acetylcholine – a neurotransmitter involved in muscle activity and memory – an underproduction involved in Alzheimer’s
36
Define neuromodulators
Neuromodulators have a more widespread and generalised influence on synaptic transmission
37
Give an example of a neuromodulator
Endorphins – they travel through the brain circulatory system and inhibit pain and enhances neural activity which produces pleasurable feelings
38
Define neuropsychology
The study of the function in the brain by investigating the effects of brain damage on mental functions - often in forms of case studies
39
Name the six types of brain lesions and try and expand on each of them
* Vascular – disruption to blood flow – this may be caused by blockages or enlarged arteries (stroke/aneurysm)
* Tumour – mass of tissue with no physiological function – this grows and disrupts functioning
* Degenerative diseases – breakdown of neurological material – each disorder presents different symptoms e.g. Alzheimer’s or Parkinson’s
* Trauma – violent assault to the head
* Infectious diseases – a virus can result in neurological symptoms e.g. HIV, AIDS, herpes
* Epilepsy – brief loss of consciousness resulting from excessive electrical activity in the brain – this can be triggered by trauma and can disrupt activity over wide areas
40
What is the difference between single association and double association?
Single association is just when observations are made from one patient and when they show a struggle in a certain action or behaviour, this suggests that there could be a link between the part of the brain that is damaged OR it could be explained by problems with the design. BUT double association is where two people with different brain lesions complete two different tasks. If patient A is impaired at task A, but performs well on task B and patient B performs well on task A, but is impaired on task B then we can say with much more confidence that the differences in performance are seen due to the brain abnormalities.
41
Explain Wenicke's aphasia
Results from damage in the temporal lobe and is primarily manifested as difficulties with speech comprehension.
42
Explain Broca's aphasia
Results from damage in the frontal lobe and is primarily manifested as difficulties with the production of speech.
43
Brian function partly consists of __________
The answer is 'electrical activity' - measuring this can be used to infer brain functions
44
Name a method of measuring electrical activity in the brain
Electoencephalography (EEG) - measures the activity of large groups of neurons through a series of large electrodes placed on the scalp
45
Name three advantages of EEG
* Not painful or invasive
* Useful for studying sleep-wave patterns – specific EEG patterns relate to different states of consciousness
* Can signal presence of brain disorders
46
name two disadvantages of EEG
* Sticky – so it is unpleasant
| * Non-specific measure – doesn’t focus on specific brain area
47
What does MRI stand for and what is it?
Magnetic resonance imaging - creates images based on how atoms in living tissue respond to a magnetic pulse delivered by the device. Magnetic field causes molecules and atoms to respond - the signal emitted is detected a mapped. This measures structure.
48
Name an advantage of MRI
No risk from xrays
49
What does fMRI stand for and what is it?
Functional magnetic resonance imaging - can produce pictures of blood flow in the brain taken less that a second apart. Oxygenated and de-oxgenated blood responds differently to magnetic field. The more oxygen, the more activity, so where the highest concentrations of oxygen this is where the activity has been taking place.
50
Name two advantages of fMRI
* Fairly good images
| * Magnets less risky
51
What does PET scan stand for and what is it?
Position-emission tomography scan - measure brain activity including metabolism, blood flow and neurotransmitter activity. Glucose is a nutrient for neurons, so high levels of glucose indicate high activity. A radioactive form of glucose is injected into bloodstream.
52
Name an advantage of PET scans
can label particular neurotransmitters
53
Name a disadvantage of PET scans
radioactive and invasive - individual cannot be studied overtime due to the risks radioactivity pose, therefore, cannot be used in developmental studies
54
Name the three major subdivisions of the brain
Hindbrain, Midbrain and Forebrain
55
Define the hindbrain - and what does it include?
The lowest and most primitive level of the brain. It includes the medulla and pons, brain stem and the cerebellum
56
What does the brain stem do and what does it include?
Supports vital life functions. It include the meduall and pons
57
What does the medulla do?
It plays an important role in vital body functions such as heart rate and respiration. It also has sensory and motor nerve tracts coming up through from the spinal cord and down descending from the brain. The first structure above the brain stem
58
What does the pons do?
Relays sensory information between the cerebral cortex and the cerebellum. Also helps regulate sleep and helps control respiration. Lies just above the medulla.
59
What does the cerebellum do?
Concerned primarily with muscular movement and coordination, precise timing. Alcohol can disrupt motor control functions. Also plays role in learning and memory.Attached to the rear of the brain stem.
60
What can damage of the cerebellum cause?
Severe motor disturbances - jerky and uncoordinated movements
61
Define the midbrain and what it includes?
Contain clusters of sensory and motor neurons. within the midbrain is reticular formation.
62
What does reticular formation do?
It alerts higher centre of the brain that messages are coming ad then either blocks them or allows them to go forward. It plays a central role in consciousness and attention. Prevents us from becoming overwhelmed by only allowing important information to enter our consciousness.
63
Give an example of a part of the brain that general anaesthetics deactivate
Reticular formation. Ordinarily the messages occurring would cause pain
64
What could damage to the reticular formation cause?
A permanent coma
65
Define the forebrain and give a few examples of what it includes?
The brain's most recently evolved portion. Its major structure is the cerebrum. It also consists of the thalamus, hypothalamus, limbic system, hippocampus, amygdala, cerebral cortex, motor cortex, sensory cortex, association cortex, frontal lobes, prefrontal cortex.
66
What is the cerebrum?
The most superior part of the forebrain. It consists of the two hemispheres, which wrap around the brain stem. Comprise of the cerbral cortex and several more central structures.
67
What is the thalamus?
Sometimes likened to a switchboard that organises inputs from sensory organs and routes them to the appropriate areas of the brain. The visual, auditory and body sense have major relay stations here
68
What can damage to the thalamus cause?
Sensory confusion - it has been linked to schizophrenia
69
What is the hypothalamus?
plays a major role in motivation and emotion including sexual behaviour, temperature regulation, sleeping, eating, drinking and aggression. It is closely linked with the pituitary gland (the hypothalamus directly controls many hormonal secretions). Links with dopamine
70
Hypothalamus and the dopamine system.. explain
It is involved with experiences of pleasure, so is important for reward and punishment. Dopamine causes pleasure, but less dopamine secreted when horrible experiences occur.
71
What is the limbic system?
helps coordinate behaiours needed to satisfy motivational and emotional urges that arise in the hypothalamus. Also involved in memory. Two key structures of the limbic system are the hppocampus and the amygdala.
72
What is the hippocampus?
It is involved in forming and retrieving memories. Navigation is big here - like a 3D map.
73
What does damage to the hippocampus cause?
Different types of amnesia
74
What is the amygdala?
It underlies emotional behaviours, particularly those linked to aggression and fear. This is important for emotional memories because there are interconnections between this and the hippocampus.
75
What is the cerebral cortex?
0.63 cm thick sheet, consisting primarily of grey matter (unmyelinated). It is the outermost layer of the human brain and is wrinkly in appearance. The bulges are called guri and the groves fisures (these allow for greater surface area). Fisures separate the brain into four lobes - frontal, occipital, parietal, temporal.
76
The cerebral cortex is not vital for physical survival but essential for human functioning - true or false
true
77
What is the motor cortex?
It controls 600+ muscles involved in voluntary movement. Each hemisphere governs the opposite side of the body. The size of the body is not directly proportional to our brains representation of them.
78
What is the sensory cortex?
It receives sensory input that gives rise to our sensations of heat, touch and cold, and to our sense of balance and body movement. The amount of cortex devoted to each body area is directly proportional to that regions sensory sensitivity. It is located in the parietal lobe
79
What is the association cortex?
It is involved in important mental functions, including perception, language and thought
80
What can damage to the association cortex cause?
Disruption or loss of speech, understanding, thinking and problem solving
81
What is agnosia?
The inability to identify familiar objects, but they aren't blind. For example, they would recognise a banana but not be able to tell you it was as a banana - they cannot link the visual to the object.
82
What are the frontal lobes?
They make up 29% of the human brain. They are involved in planning, initiative and responsibility. Least understood part of the brain because it is very delicate. Also involved in emotional responses.
83
What can damage in the frontal lobes cause?
* Inability to plan and carry out sequenced actions
| * Lack of empathy, inability to have different experiences with pleasant and unpleasant.
84
What is the prefrontal cortex?
It is located just behind the forehead and is the seat of the so-called executive functions. It allows people to be adaptive
85
What does damage to the prefrontal cortex cause?
Problems planning strategically, controlling impulses, setting goals and basic poor judgement. AN example is Phineas Gage
86
What connects the left and right hemisphere and explain what it is?
The corpus callosum. It is a neural bridge consisting of white matter tracts that acts as a major communication link between the tow hemispheres and allows them to function together.
87
Define lateralization.
Refers to the relativity greater localisation of function in one hemisphere or the other
88
What is localised in the left hemisphere?
* Verbal abilities – language and speech
* Mathematical abilities
* Logical abilities
89
Why are women less likely to experience aphasia when the left hemisphere is damaged?
Because language is represented in both hemispheres to a greater extent than men
90
What is localised in the right hemisphere?
* Perceptions of spatial relations
* Mental imagery
* Musical abilities
* Artistic abilities
* Also, negative emotions are more active here than in the left hemisphere
91
What happens when the corpus callosum is severed, and what was this once a common procedure for?
It disrupts the communication between the left and right hemisphere. It was a common procedure at one time for epilepsy patients to stop the spreading of electrical activity all over the brain.
92
Who did research on split brain patients?
Sperry (1970)
93
Explain Sperry's research which flashed words to different visual fields of split brain patients.
When words were flashed to the RVF, therefore received by the left hemisphere, patients could describe what they saw. But, when the words were flashed to the LVF, therefore recieved by the right hemisphere, patients couldn't describe what they had seen. These patients were told to use their left hand to draw what they had seen
94
Explain Sperry's research which flashed up pictures to different visual fields of split brain patients. NEED TO LOOK IN BOOK, ACTUALLY GOT CONFUSED
If the picture flashed in the RVF then the left hemisphere allowed the patient to name the object straight away. But, when the picture flashed in the LVF patients were unable to pick out the object that matches
95
Explain Sperry's research which showed split brain patients images of faces made out of different objects.
The right hemisphere is superior with facial recognition. SO if the image was shown to the LVF, the patient would recognise the image as a face, but if the image was shown in the RVF, the patient would describe the image as different objects (books, watches, fruit)
96
Define neural plasticity
the ability of neurons and brain areas and networks to change in structure and function
97
What may change the size of certain areas and neural pathways?
Learning and practising mental or physical skills
98
Name different factors that may cause changes in the brain,
• Stimulating environments
o Prematurely born infants – caressed and massaged show faster neurological development in comparison to those who received normal human contact
• Cultural factors
o The Chinese language comprises complex pictorial symbols – because images are processed by the right hemisphere language isn’t lateralised in just left hemisphere for Chinese speakers
• Occupational factors
o Maguire (2002) – London taxi drivers required to have vast knowledge of London’s streets, so they have larger posterior hippocampuses
99
How do neurons modify themselves? (two ways)
* Structurally – sprouting enlarged networks of dendrites or extending axons from surviving neurons
* Biochemically – surviving neurons can make up the loss by increasing neurotransmitter volume
100
Define neurogenesis
Production of new neurons in the nervous system
101
Define neural stem cells
immature 'uncommitted' cells that can mature into any type of neuron/glial cell needed by the brain - can be directly injected into the brain and it will travel to the region which is degenerated or underdeveloped. The discovery of this may led to interventions for severed spinal cords or diseases like Alzheimer's, multiple sclerosis or strokes.
102
Define the endocrine system
Consists of numerous hormone-secreting glands distributed throughout the body. It passes information via hormones.
103
What is a hormone
Chemical messengers that are secreted from glands into the bloodstream. Cells in body have specific receptor molecules for specific hormones. Transmitted much more slowly than neurotransmitters, but have a more widespread and prolonged effect.
104
Name as many hormone glands as you can. (There are 8)`
pituitary (the master gland), hypothalamus, thyroid, testes, ovaries, adrenal medulla, adrenal cortex, pancreas
105
Explain what the adrenal glands are
Twin structures perched on top of the kidneys that produce and secrete about 50 different hormones. In an emergency, they are triggered by the sympathetic branch of the autonomic nervous system. They mobilise the bodies stress response system.
106
Explain what the role of the immune system is.
Hunt and destroy invaders that could kill or disable you - this is done with microscopic 'soldiers' that patrol every part of our bodies.
107
Define antigens
Foreign substances that trigger a biochemical response from the immune system. Once the brain has identified an antigen once, it will always remember it and how it can be destroyed.
108
Define antibodies
Biochemical weapons needed to destroy antigens
109
what factors can decrease immunity?
o Chronic stress
o Depression
o Pessimistic thinking
110
what factors increase immunity?
o Management skills
o Optimistic thinking
o Sense of humour
o Social support
