Miss Adkins Biological Flashcards
what makes up the central nervous system?
brain and spinal cord
how does the CNS communicate wit the body?
through the peripheral nervous system
What are neurotransmitters?
chemicals in the nervous system. They send messages between neurons through the synapses
neurotransmitters can be either…
excitatory (more likely to action potential) or inhibitory (less likely to action potential)
what is a neuron?
nerve cells that transmit and receive chemical messages by the release and uptake of neurotransmitters
describe the process of action potential
electrical impulse is triggered by a change in electrical potential of the neuron (when it becomes more positive it depolarises), it passes down the axon to stimulate the release of a neurotransmitter
describe the process of synaptic transmission
action potential triggered in pre-synaptic neuron. Impulse travels down the axon. axon terminals release neurotransmitter from vesicles. neurotransmitter travels across synapse. receptors of the post-synaptic neuron absorb the transmitter. sometimes re-uptake takes place
explain the effect of recreational drugs on synaptic transmission
drugs either increase or decrease neurotransmitter operations. E.g. dopamine provides a reward pathway to encourage us to repeat the drug taking
how can recreational drug taking lead to addiction?
heroin- increases dopamine and causes euphoria. the brain responds with downregulation (lowering naturally produced dopamine). dysphoria encourages reusing drugs. over time, more drug is needed for euphoria
evidence that addiction is not biological
Alexander- rat park- free rats drank plain water. addicted rats moved from cages voluntarily went through withdrawal as their environment causes euphoria
function of the corpus callosum
bundle of nerve cells that allows the left and right hemispheres to communicate and act as one whole organ
What is brain lateralisation?
left and right halves have specialised functions e.g. left side controls language and the right controls creativity and musicality
Name the four lobes of the brain
frontal lobe (front)
parietal lobe (top)
occipital (back)
temporal (side)
state the function of the cerebellum
balance, coordination and motor skills
explain how the amygdala leads to aggression
centre of emotion, it controls reactions to environments, connects the pre-frontal cortex and includes control of emotion e.g. aggression
Explain how the pre-frontal cortex leads to aggression
impulse control, behaviour regulation and thinking through our actions. if damaged, we can’t control impulses so may be agressive e.g phineas gage
what evidence suggests that aggression is caused by brain functioning?
Phineas Gage and Charles Whitman
Explain the weaknesses of brain functioning as an explanation of aggression
case studies are based on one individual, group or event. Phineas and Charles are unique cases that we cannot replicate ethically. Cannot generalise
explain the role of evolution in the onset of aggression
natural selection- aggression has an adaptive benefit and is more likely to be passed on in sexual selection. In the EEA, aggression was beneficial as they lived in hunter-gatherer groups
what evidence suggests that aggression serves an adaptive purpose?
Townsend- females prefer dominant males
explain the weaknesses of evolution as the cause of aggression
post-hoc, theory was developed after the facts, cannot be tested today
Explain Freud’s tripartite model of the mind
Id- pleasure principle, internal desires
Ego- reality principle, referees between the id and superego’s morals
Superego- morality principle, societal rules and morals
Explain the two drives within Freud’s concept of the id
Eros- life instinct, reproduction and maintenance of life
Thanatos- death instinct, self-destruction
Explain Freud’s concept of catharsis as a way to reduce aggression
releasing anger without hurting yourself or others. E.g. video games or slamming a door
Explain the weaknesses of Freud’s explanation of aggression
Reductionist, cannot operationalise the concepts, non-scientific
explain what hormones are an how they are linked to aggression
Chemical messengers that transmit info around the body, released by the endocrine system. they take longer to produce change than neurotransmitters. testosterone causes aggression
evidence linking testosterone with aggression
Wagner et al- catrated rats to lower aggression, injected them with testosterone and their aggression levels rose again
state one similarity and one difference between biological and psychodynamic explanations of aggression
similarity- external factors contribute, nature cause
difference- operalisationable concepts
what is a twin study
comparison of MZ and DZ twin similarity (concordance rates).
what are twin studies used for?
to see if a behaviour is due to nature or nurture
to see if MZ’s are more similar than DZ’s, a biological cause is assumed
explain which stats test you used in the biological practical and why
spearmans rho to see the correlation between height and aggression. ordinal data used e.g. mean aggression out of 5
state the hypothesis of your biological practical
there will be a significant positive correlation between height in cm and self-rated aggression levels on a scale of 1-5
