Biopsychology Flashcards
The nervous system
Central nervous system - peripheral - brain and spinal chord
Peripheral nervous system:autonomic and somatic
nervous system- ANS: Parasympathetic and sympathetic nervous system
Highly organised hierarchical system
Peripheral nervous system
Transmits info from the environment to CNS and from CNS to other parts of body
Central nervous system
Processes info and prepared responses
Brain
Control centre
Spinal cord
Where most of the info travels to get to and from the brain
Autonomic nervous system
Controls activities of internal organs
Somatic nervous system
Carries info from the environment to CNS and instructions from CNS to skeletal muscles
Parasympathetic nervous system
Involved in homeostasis
Sympathetic nervous system
Involved in fight/flight response
Biological approach
A perspective that emphasises the importance of physical processes in the body such as genetic inheritance and neural function
Genes
Make up chromosomes and consist of dna which codes the physical features of an organism and psychological features
Genes are transmitted from parents to offspring. Inherited
Biological structure
An arrangement or organisation of parts to form an organ, system or living thing
Neurochemistry
Relating to chemicals in the brain that regulate psychological functioning
Genotype
The particular set of genes that a person possesses
Phenotype
The characteristics of an individual determined by both genes and the environment
Evolution
The changes in inherited characteristics in a biological population over successive generations
The biological approach assumptions
It suggests that everything psychological is at first biological, so to fully understand human behaviour, we must look to biological structures and processes within the body, such as genes, neurochemistry and the nervous system
An understanding of brain structure and function can explain our thoughts and behaviour
The genetic basis of behaviour- the biological approach
Behaviour geneticists study whether behavioural characteristics (eg intelligence) are inherited in the same way as physical characteristics (eg height and eye colour) Twin studies are used to determine the likelihood that certain traits have a genetic basis by comparing the concordance rates between pairs of twins; that is, the extent to which both twins share the same characteristics If identical (monozygotic) twins are found to have higher concordance rates than non identical (dizygotic) twins- for musical ability, schizophrenia or whatever - this would suggest a genetic basis. This is because MZ twins share 100% of each other’s genes, whilst DZ twins share about 50% (the same as any siblings)
Genotype and phenotype- the biological approach
Genotype- Pearson’s genetic makeup
Phenotype- way that genes are expressed through physical, behavioural and psychological characteristics
Expression of genotype is influenced by environmental factors
Evolution and behaviour- the biological approach
Charles Darwin proposed theory of natural selection in 19th century
Main principle of the theory is that any genetically determined behaviour that enhances an individual’s survival sol continue in future generations ie being naturally selected
Evaluation points of the biological approach
Scientific methods of investigation Real life application Casual conclusions Determinist view of behaviour Cannot separate nature and nurture
Scientific methods of investigation evaluation of the biological approach
Large range of precise and highly scientific methods. E.g twin study on depression. Compared concordance rates for identical and non identical twins. Higher chance of both identical twins getting it. 49%
This means the biological approach is based on reliable data
Real life application evaluation of the biological approach
Increased understanding of biochemical processes in the brain has led to the development of psychoactive drugs that treat serious mental illness eg depression
Although these drugs are not affective for all patients, they have revolutionised treatment for many
Strength because it means that sufferers are able to manage their condition and live a relatively normal life rather than remain in hospital
Casual conclusions evaluation of the biological approach
The BA offers explanations for mental illness in terms of the action of neurotransmitters in the brain
The evidence for this relationship comes from studies that show a particular drug reduces symptoms of a mental disorder and thus it’s assumed that the neurochemical in the drug causes the disorder
Limitation because the biological approach is claiming to have discovered causes where only an association exists
Determinist view of behaviour evaluation of the bio approach
the approach sees behaviour as governed by internal, biological causes over which we have no control. this has implications for the legal system and wider society. one of the rules of law is that offenders are seen as legally and morally responsible for their actions the discovery of a ‘criminal gene’ may complicate this principle.
cannot separate nature and nurture evaluation of the bio approach
identical twins, non identiocal twins and family members all have genetic similarities. therefore the bio approach argues any similarities in the way they look or behave must be genetic. however there is an important confounding variable. they are also exposed to similar environmental condition. this means that findings could just as easily be interpreted as supporting nurture rather than nature.
twin study
study of depression, a researcher investigated the gentic basis of the disorder. one way to do this is to compare concordance rates for identical twins (monozygotic) who have exactly the same genes with non identical twins (dizygotic) who share about 50%. both kinds of twins grow up in similar environments. concordance rates express the likelihood that a trait present in one twin is also found in the other twin.
MZ twins- 49% DZ twins-17% ordinary siblings-9%
the endocrine system
One of the body’s major information systems that instructs glands to release hormones directly into the blood stream. These hormones are carried towards target organs in the body
gland
an organ in the body that synthesises substances such as hormones
hormones
chemical substances that circulate in the blood stream and only effect target organs. They are produced in large quantities but disappear quickly. Their effects are very powerful
fight or flight response
the way an animal responds when stressed. The body becomes physiologically aroused in readiness to fight an aggressor or flee
adrenaline
hormone produced by the adrenal glands which is part of the human body’s immediate stress response system. Adrenaline has a strong effect on the cells of the cardiovascular system- stimulating the heart rate, contracting blood vessels and dilating air passages.
thyroid glands
produces the hormone thyroxine. This hormone affects cells in the heart (increases heart rate). It also affects cells throughout your body increasing metabolic rates
the main glands in the endocrine system
hypothalamus, pituitary, thyroid, parathyroid, adrenal, pancreas, ovaries and testes
the major endocrine gland
is the pituitary glands, located in the brain. It is often called the master gland because it controls the release of hormones from all the other endocrine glands in the body
what happens when a stressor is perceived?
the first thing that happens is the autonomic nervous system changes from its normal resting state (the Parasympathetic state) to the physiologically aroused, sympathetic state . Second, the pituitary glands releases adrenocorticotrophic hormone. 3rd, this hormone has an effect on the cells of the adrenal glands, causing them to release adrenaline into the blood stream . Adrenaline triggers physiological changes in the body which creates the physiological arousal necessary for the fight or flight response
neuron
- the basic building blocks of the nervous system, neurons are nerve cells that process and transmit messages through electrical and chemical signals
sensory neurons
- these carry messages from the PNS to the CNS .they have long dendrites and short axons
relay neurons
- connect the sensory neurons to the motor or other relay neurons . have they have short dendrites and short axons
motor neurons
these connect the CNS to affectors such as muscles and glands. they have short dendrites and long axons
types of neurons
motor, sensory and relay.
structure of a neuron
neurons vary in size from less than a millimetre to up to a metre long , but all share the same basic structure . the cell body includes a nucleus , which contains the genetic material of the cell .branch-like structures called dendrite protrude from the cell body. These carry nerve impulses from neighbouring neurons towards the cell body. The Axon carries the impulses away from the cell body down the length of the neuron. The Axon is covered in a fatty layer of myelin sheath that protects the Axon and speeds up electrical transmission of the impulse. If the myelin sheath was continuous this would have the reverse effect and slow down the electrical impulse. Thus, the myelin sheath is segmented by gaps called nodes of Ranvier. These speed up the transmission of the impulse by forcing it to jump across the gap along the axon. At the end of the axon are terminal buttons that communicate with the next neuron in the chain across the gap known as the synapse.
electrical transmission
when a neuron is in a resting state the inside of the cell is negatively charged compares to the outside. When a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second causing an action potential to occur. This creates an electrical impulse that travels down the axon towards the end of the neuron.
synaptic transmission
the process by which neighbouring neurons communicate with each other by sending chemical messages across the gap that separates them
excitation
when a neurotransmitter such as adrenaline increases the positive charge of the postsynaptic neuron. This increases the likelihood that the neuron will fire and pass on the electrical impulse
inhibition
when a neurotransmitter such as serotonin increases the negative charge of the post synaptic neuron. This decreases the likelihood that a neuron will fire and pass on the electrical impulse.
chemical transmission
- Neurons communicate with each other within groups known as neural networks. Each neuron is separated from the next by tiny gap called the synapse. Signals withing neurons are transmitted electrically, however, signals between neurons are transmitted chemically across the synapse. When the electrical impulse reaches the end of the neuron it triggers the release of neurotransmitter from tiny sacs called synaptic vesicles
neurotransmitter
chemicals that diffuse across the synapse to the next neuron in the chain. Once it crosses the gap, it is taken up by the postsynaptic receptor site- the dendrites of the next neuron. Here, the chemical message is converted back into an electrical impulse and the process of transmission begins again in this neuron. Several dozens types of neurotransmitter have been identified in the brain, each has its own specific molecular structure that fits perfectly into a post synaptic receptor site. Neurotransmitters also have specialist functions
excitation and inhibition
neurotransmitters have either an excitatory or inhibitory effect on the neighbouring neuron. Eg the neurotransmitter serotonin causes inhibition in the receiving neuron, resulting in the neuron becoming more negatively charged and less likely to fire. In contrast, adrenaline causes excitation of the post synaptic neuron by increasing its positive charge and making it more likely to fire
