biopsychology Flashcards
(103 cards)
1
Q
the nervous system
A
• the body’s main communication system which is very fast acting
• it is a complex network of specialised nerve cells which passes information around the body
•it passes messages using electrical signals and chemicals using neurones and neurotransmitters
2
Q
what is the CNS made up of
A
brain and spinal cord
3
Q
what is the function of the CNS
A
pass messages from the brain to other parts of the body along with receiving information from PNS.
4
Q
what is special about the brain
A
the brain is the centre of conscious awareness. the cerebral cortex is highly developed in humans and distinguishes out higher mental functions from other animals.
5
Q
what is the spinal cord
A
the spinal cord is an extension of the brain. It is responsible for reflex actions
6
Q
what is the peripheral nervous system
A
send information to the CNS from the outside world and transmits messages from the CNS to muscle ls and glands in the body
7
Q
what’s the PNS made up of
A
nerve fibres (axons) which are connected to the CNS
8
Q
what is the somatic nervous system
A
•revives instructions from the CNS for muscle movement.
•controls conscious movement.
•transmits information from receptor cells in sense organs to the CNS.
9
Q
what type of neurones is the somatic nervous system made up of
A
myelinated neurones
10
Q
what is the automatic nervous system
A
• responsible for control of the bodily functions unconsciously directed
•transmits information to and from internal bodily organs
11
Q
what is the autonomic nervous system made up of
A
•unmyelinated nerve fibres
• two main division : sympathetic nervous system and parasympathetic nervous system.
12
Q
sympathetic nervous system
A
gets body prepared for fight or flight
13
Q
parasympathetic nervous system
A
returns body to its normal resting state
14
Q
what is a neuron
A
nerve cells which are part of the nervous system
15
Q
how do neurones transit information
A
they transmit signals two ways:
•electrically (though action potential)
•chemically (using neurotransmitters)
16
Q
what do all neurones consist of
A
cell body, dendrites and an axon
17
Q
what are dendrites and what do they do
A
dendrites at one end of the neuron receives signals from other neurons or from sensory receptors. dendrites are connected to the cell body
18
Q
what is the function of the cell body
A
the control centre of the neuron which contains all the genetic information of the cell.
19
Q
what is the axon
A
the impulse is carried along the axon where it terminates at the axon terminal
20
Q
what is the axon terminal
A
the end of the axon where neurotransmitters are found
21
Q
what is a myelin sheath
A
a fatty coating that surrounds the neuron, allows nerve impulses to transmit more rapidly along the axon. If damaged they slow down.
22
Q
function of sensory neuron
A
carry messages from the sense receptors in the PNS to the CNS
23
Q
what size dendrites and axons do sensory neurons have
A
•long dendrites
•short axons
24
Q
what is the function of a relay neuron
A
•connect the sensory neurons to the motor or other relay neurons. allowing motor and sensory neurons to communicate with each other
•they are found only in the brain and spinal cord
25
what size dendrites and axons do relay neurons what
• short dendrites
• short axons
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what is the function of a motor neuron
•connect the CNS to effectors such as muscle glands
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what size dendrites and axons do motor neurons have
• short dendrites
• long axons
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where is the motor neurons cell body and axon located
the cell body is in the spinal cord the fibre (axon) projects outside the spinal cord to directly or indirectly control effector organs.
29
synaptic transmission
the process in which one neuron communicates with another by releasing neurotransmitters to diffuse across the synapse.
30
synapse
- the gap of the end of the axon of one neurone and the dendrite or cell body of another.
- the signal needs to cross the gap to pass on its message. this is done using neurotransmitters that diffuse across the gap between the two neurones.
31
action potential
electrical impulse. when a neurone is in a resting state it is negatively charged compared to the outside. when a neurone is activated by a stimuli it becomes positively charged for a split second causing an action potential to travel down the axon.
32
stages of synaptic transmission
1. an action potential travels down the axon of the pre-synaptic neuron
2. when it reaches the terminal buttons it causes vesicles to migrate and bind with the pre-synaptic membrane triggering the release of a neurotransmitter.
3. neurotransmitters diffuse across the synapse and bind with postsynaptic receptors like a lock and key.
4. once activated the receptors produce either excitatory or inhibitory effects on the postsynaptic neurone
5. Neurotransmitters are then released back into the synapse and go through the process of re-uptake or get metabolised.
33
What is the Endocrine system
-It is a communication system that instructs glands to release hormones directly into the bloodstream.
-These hormones are carried in the blood towards target organs in the body.
-It works alongside the NS to control vital functions in the body.
34
What speed does the endocrine system send messages compared to nervous system
It acts much more slowly than the NS but still has powerful effects.
35
Hormone
•A chemical substance that circulates in the bloodstream and affects target organs.
•Hormones can affect cells in several organs leading to a diverse range of responses
36
What does the hypothalamus do
•The hypothalamus is a brain region which is connected to the pituitary gland. is responsible for stimulating or controlling the release of hormones from the pituitary gland.
•regulates the endocrine system.
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Pineal gland
- releases melatonin
- responsible for important biological rhythms, including the sleep-wake cycle
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Thyroid gland
- releases thyroxine
- responsible for regulating metabolism
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Pituitary gland
•master gland
•the hormones released by this gland control and stimulate the release of hormones from other glands
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Ovaries
- releases oestrogen
- controls the regulation of the female reproductive system, including the menstrual cycle and pregnancy.
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Testes
- releases testosterone
- responsible for the development of make sex characteristics during puberty while also promoting muscle growth
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Adrenal gland (medulla)
- releases adrenaline and noradrenaline
- the key hormone in the fight or flight response
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Adrenal gland cortex
- releases cortisol
- stimulates the release of glucose to provide the body with energy while suppressing the immune system.
44
function of serotonin
regulates mood
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function of dopamine
•gives feeling of pleasure
•involved in reward pathways that lead to addiction
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function of GABA
•has calming effect on the brain
47
inhibition
•”off switch” responsible for calming the mind and body
•a negative charge at the post synaptic membrane will create an inhibitory post synaptic potential do is less likely to fire an action potential in the next neuron
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excitation
•”on switch”
•a positive charge at the post synaptic membrane will create an excitatory postsynaptic potential so is more likely to fire an action potential in the next neuron
49
summation
the net sum of the total IPSPs and EPSP which determines whether or not the cell fires.
50
fight or flight response
a sequence of activity within the body that is triggered when the body prepares itself for defending or attacking or running away to safety. this activity involves changes in the NS and the secretion of hormones that are necessary to sustain arousal
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how are threats today different to the past
threats are more psychological rather than psychological
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what is the role of the amygdala
the amygala is your body’s threat sensor. if it alerts that there is a threat then it will activate a sequence of events.
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which two communication systems work together
nervous system & endocrine system
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what does localisation of function mean
functions such as movement, speech and memory are performed in distinct region of the brain
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how does localisation of the brain contrast the holistic view
-they believe that all parts of the brain are involved in the processing of thought and action.
- before scientific research or the brain was believed the brain worked holistically
56
what is the outer layer of the brain called
cerebral cortex (separates humans from other animals)
57
what are the four lobes of the brain
frontal, parietal, temporal, occipital lobes
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who where the 2 neurosurgeons known for identifying areas of the brain associated with speech processing
Broca & Wernicke
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the motor area
found in the frontal lobe, this area is involved in regulating and coordinating movements
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the auditory area
An area of the temporal lobe, which is responsible for processing auditory information and speech.
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visual area
An area in the occipital lobe which is responsible for processing visual information.
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the somatosensory area
An area of the parietal lobe which processes sensory information from the skin e.g. touch, heat, pressure etc.
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Wernickes area
Responsible for speech comprehension and located in the left temporal lobe.
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Broca’s area
Responsible for speech production and located in the left frontal lobe
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what is brocas aphasia
speech that is slow, laborious and lacks in fluency
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what is wenickes aphasia
produces nonsense words
67
hemispheric lateralisation
The idea that 2 hemispheres of the brain are functionally different and that certain mental processes/behaviours are mainly controlled by one hemisphere rather than the other
eg example language
68
difference between localisation and lateralisation
•Localisation is the identification of function in a specific region of the brain
•Whereas lateralisation is the identification of a function in one hemisphere
69
which hemisphere processes the left visual field
right hemisphere
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which hemisphere processes the right visual field
the left hemisphere
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what is the right hemisphere responsible for
specialises in visual-spatial processing and facial recognition
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what is the left hemisphere responsible for
speech and language
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contralateral control
the right hemisphere controls the left side of the body and vice versa
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sperry’s split brain research
aim: to asses the abilities of separated brain hemispheres
procedures: 11 ps who had split brain surgery where show info to either right visual field (LH) or left visual field (RH). in normal brains the corpus callosum would share info between hemispheres giving complete visual world. However ps information cannot be shared from one hemisphere to the other
findings: when shown to RVF ps could describe what was seen but not if LVF, could only pick out associated objects. this is due to messages from the RH being relayed to language centre in LH but not possible in split brains
conclusion: certain functions are lateralised in the brain and support the LH= verbal and RH=visual spacial
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the sympathomeduallary pathway
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Broca’s research
procedure: Studied a patient called Tan and eight other postmortems who had speech production issues and lesions in their left frontal hemisphere.
findings: This led Broca to identify the existence of a language centre for speech production in the posterior portion of the frontal lobe of the left hemisphere (Broca's area).
77
Wernickes research
procedure: Studied a patient who
suffered a stroke and could not understand language. He studied his brain post-mortem.
findings: This led Wernicke to identify that the area of the brain involved in language. He understanding language was in the posterior portion of the left temporal lobe (Wernicke's area).
78
Plasticity
The brain can change and adapt over time as a result of experience and brew learning
79
Infant development and plasticity
-During infancy the brain experiences growth in the number of synaptic connections it has
- it was originally thought that such changes were restricted to the developing brain and that the adult brain, beyond a critical period, would remain fixed
80
Synaptic pruning
Extra neurons and synaptic connections are eliminated in order to increase the efficiency of neuronal transmission
81
examples of plasticity
1.Romanian orphans suffered conditions of neglect and understimulation.
PET scans of their brains show hypometabolism in the temporal lobes, indicating lack of neural development.
2. Davidson et al (2004) found that Tibetan monks had increased gamma waves (coordinate neuronal activity) when meditating. This showing long term changes
3. Rosenweig et al (1972) brains of the enriched rats were different from the impoverished rats; the neurons were larger, the cerebral cortex heavier and thicker.
4. Boyke et al (2008) - there is a natural decline in cognitive functioning with age. Boyke found that 60year olds had increased grey matter in the visual cortex when learning to juggle. It decreased when they stopped
82
Maguires study
Aim: whether participants with extensive experience in the use of navigational skills would show increased brain volume in their posterior hippocampus
Method: 16 male right-handed taxi drivers were compared to 50 healthy right-handed males who were not taxi drivers. The taxi drivers have to undergo extensive navigational training. Using MRI, the volume of the hippocampus was compared between groups
Results: taxi drivers showed an increase in volume of the posterior hippocampus, compared to healthy volunteers.
Conclusion: extensive practice with spatial navigation affects the hippocampus.
83
functional recovery
A form of plasticity where following damage from trauma the brain is able to redistribute functions normally performed by damaged areas to other undamaged areas
84
when is functional recovery more likely
at a younger age
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types of functional recovery
1. neural reorganisation
2. neurogenesis (neural regeneration)
86
neural reorganisation
•Healthy brain areas may take over the functions of those areas that are damaged, destroyed or even missing.
•This process can occur quickly after trauma (spontaneous recovery)
•Through the recruitment of homologous areas, the opposite side of the brain is used to perform a specific task.
87
4 methods of studying the brain
•FMRI
•EEG
•EEP
• post-mortem
88
spacial resolution
the smallest feature that a scanner can detect. greater this is makes it easier to discriminate between brain regions with more accuracy.
89
temporal resolution
accuracy of the scanner in relation of time or how quickly the scanner can detect changes
90
fMRI
• measures changes in blood oxygenation in the brain when a person performs a task
• an active brain area consumes more oxygen and is used by neurons (becoming deoxygenated).
• Oxy- and deoxygenated blood have different magnetic properties, detected by the fMRI scanner
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strengths of fMRI
•high spacial resolution
• non invasive
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limitations of fMRI
•low temporal resolution
•expensive
•indirect measure
•movement artefact
•accessibility (metal,pregnancy)
93
EEG
• measure electrical activity within the bran via electrodes that are fixed on the scalp.
• It works on the assumption that information is processed in the brain as electrical activity in the form of action potentials.
94
what is the basis for the EEG signal
Small electrical charges are detected by the electrodes and graphed over a period of time indicating the level of activity.
95
the 4 types of EEG waves, and how do they differ?
• There are alpha, beta, theta and delta.
• They are measured in amplitude and frequency
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advantages of EEG
•high temporal resolution
•non invasive
•low cost
•portable
•direct neural measure
•wide range of populations
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limitations of EEG
•low spacial resolution
•susceptible to artefacts
•limited to surface area
•interpretation
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ERPs
•are a way to isolate specific neural l responses associated with
sensory, cognitive, and motor events
• These are of interest to cognitive neuroscientists.
• use a statistical averaging techniques, that filters out extraneous brain activity from the original EEG recording, leaving only the responses that relate to the presentation of a specific stimulus or performance of a specific task.
• types of brainwave that are triggered by particular events.
99
advantages of ERPs
•high temporal resolution
•non invasive
•relatively low cost
•sensitive to cognition
100
limitations of ERPs
• lack of standardisation
•background noises / extraneous material must be eliminated
101
post mortem examination
•involves the analysis of a persons brain after their death.
• likely to be those who have a rare disorder and have experienced
unusual deficits in mental processes or behaviour
• Areas of damage within he brain are examined to establish the cause
• involve comparison with a neurotypical (healthy) brain in order to see difference.
102
advantages of post mortems
•vital in providing a foundation for early understanding of key processes in the brain
• improve medical knowledge and generate hypothesises
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disadvantages of post mortems
•causation
•damage to brain may not link to deficit
• ethical issues of consent
