Biological

Question 1

3.1.1 what is the central nervous system?

Answer 1

consists of the brain and the spinal cord and is the origin of all complex commands and decisions.

Question 2

3.1.1 describe the spinal cord.

Answer 2

links the peripheral nervous system (PNS) to the CNS via the brainstem and is responsible for reflex actions.

Question 3

3.1.1 describe the brain.

Answer 3

source of conscious awareness.
consists of two hemispheres and has contralateral control of the body.
cerebral cortex is the top layer (3mm thick).
cerebral cortex is highly developed in humans distinguishing our mental function from that of other animals.

Question 4

3.1.1 what are the subcortical structures?

Answer 4

parts of the brain below the cerebral cortex.

include the thalamus, hypothalamus, limbic system, cerebellum and corpus callosum.

Question 5

3.1.1 describe the role of the thalamus.

Answer 5

acts as a relay station.
receives and passes on sensory information.
acts as a gate/filter of information.

Question 6

3.1.1 describe the role of the hypothalamus.

Answer 6

controls motivational behaviours (hunger, thirst, sex).
involved in the stress response through its control of ‘flight and fight’.
maintains balance in many bodily functions such as temperature (homeostasis).
regulates the activity of the endocrine system via its connection with the pituitary gland.

Question 7

3.1.1 describe the role of the limbic system.

Answer 7

role in memory and learning.
interconnected with the cerebral cortex.
includes the amygdala (role in emotional processing e.g. aggression).

Question 8

3.1.1 describe the role of the cerebellum.

Answer 8

consists of two hemispheres.

control balance and coordination by integrating information from the spinal cord and other areas of the brain.

Question 9

3.1.1 describe the role of the corpus callosum.

Answer 9

connects the two hemispheres below the cerebral cortex.
integrates activity of both sides of brain and body.
critical due to the brain’s contralateral control of the body.

Question 10

3.1.1 what is lateralisation and localisation.

Answer 10

two hemispheres have different functions (lateralisation).

within each hemisphere specific brain areas have specific function (localisation).

Question 11

3.1.1 describe the cerebral cortex.

Answer 11

responsible for higher cognitive processing.
four lobes per hemisphere.
convoluted surface.

Question 12

3.1.1 what are the four lobes of the cerebral cortex.

Answer 12

frontal, parietal, temporal and occipital.

Question 13

3.1.1 describe the role of the frontal lobes.

Answer 13

high level cognitive function (e.g. thinking, problem-solving, decision-making).
contains the motor cortex which controls voluntary movements.

Question 14

3.1.1 describe the role of the parietal lobes.

Answer 14

contains the somatosensory cortex which processes sensory information from the skin (e.g. touch, temperature, pressure).

Question 15

3.1.1 describe the role of the temporal lobes.

Answer 15

each lobe contains an auditory cortex which deals with sound information (processes the location, volume and pitch).
role in understanding language.

Question 16

3.1.1 describe the role of the occipital lobes.

Answer 16

each lobe contains a primary visual cortex.

responsible for processing visual information.

Question 17

3.1.1 what is Broca’s area?

Answer 17

the left frontal lobe.
a language area of the brain.
responsible for speech production.
damage to this area results in slow laborious speech lacking in fluency.

Question 18

3.1.1 what is Wernicke’s area?

Answer 18

the left temporal lobe.

damage to this area results in difficulty understanding language and fluent but meaningless speech.

Question 19

3.1.1 what is a neuron?

Answer 19

nerve cells that process and transmit messages through electrical and chemical signals.

Question 20

3.1.1 what are neurotransmitters?

Answer 20

chemicals released from synaptic vessels.
relay signals from one neuron to another across a synapse.
either perform an excitatory or inhibitory function.

Question 21

3.1.1 what is synaptic transmission?

Answer 21

the process by which neighbouring neurons communicate with each other by sending chemical messages across the tiny gap (synapse) that separates neurons.

Question 22

3.1.1 what are the three main types of neuron?

Answer 22

sensory, motor, relay

Question 23

3.1.1 describe the role of sensory neurons.

Answer 23

carry messages from sensory receptors along nerves in the PNS to the CNS.
they have long dendrites and short axons.

Question 24

3.1.1 describe the role of motor neurons.

Answer 24

carry messages from the CNS, along nerves in the PNS, to effectors (muscles and glands) in the body.
have short dendrites and long axons.

Question 25

3.1.1. describe the role of relay neurons.

Answer 25

connect sensory and motor neurons together and also connect to other relay neurons.
are only found in the CNS.
have short dendrites and short axons.

Question 26

3.1.1 describe the structure of the neuron.

Answer 26

consists of a dendrite, cell body (soma), nucleus, myelin sheath, Node of Ranvier, axon and terminal button.

Question 27

3.1.1 describe the role of the cell body (soma).

Answer 27

includes a nucleus containing the genetic material of the cell.

Question 28

3.1.1 describe the role of dendrites.

Answer 28

branch like structures that stick out from the cell body.

carry impulses from neighbouring neurons to the cell body.

Question 29

3.1.1 describe the role of the axon.

Answer 29

a tube like structure that carries the impulses away from the cell body down the length of the neuron.

Question 30

3.1.1 describe the role of the myelin sheath.

Answer 30

a fatty layer covering the axon formed from special cells.

protects the axon and speeds up electrical transmission of the impulse.

Question 31

3.1.1 describe the role of Nodes of Ranvier.

Answer 31

gapes in the myelin sheath which allow the increase in speed by forcing the impulses to ‘jump’ across the gaps along the length of the axon.

Question 32

3.1.1 describe the role of terminal buttons.

Answer 32

located at the end of the axon.

involved in the synaptic transmission (communication across a gap).

Question 33

3.1.1 describe the function of the neuron.

Answer 33

when neuron is in resting state, inside of the cell is negatively charged.
when a neuron is sufficiently activated by a stimulus, the inside of the cell becomes positively charged.
this depolarisation creates an electrical impulse, action potential, that travels down the axon towards the terminal buttons of the neuron.
the AP is generated once depolarisation reaches a certain threshold.

Question 34

3.1.1 describe the process of synaptic transmission.

Answer 34

when the action potential reaches the presynaptic terminal button it triggers the release of neurotransmitter from synaptic vesicles. 
the neurotransmitter (a chemical) diffuses across the synaptic cleft and fits into specific receptor sites n the postsynaptic neuron. 
the chemical signal carried by the neurotransmitter is converted back into an electrical signal.
neurotransmitter molecules that remain in the synapse are reabsorbed into the presynaptic neuron (reuptake).

Question 35

3.1.1 what are excitatory and inhibitory neurotransmitters?

Answer 35

inhibition in the postsynaptic neuron makes the neuron more negatively charged and less likely to fire.
excitation of the postsynaptic neuron increases its positive charge and makes it more likely to fire.

Question 36

3.1.1 what is meant by summation?

Answer 36

excitatory and inhibitory inputs are summed and neuron firing depends on net effect.

Question 37

3.1.2 what are recreational drugs?

Answer 37

drugs used for enjoyment or leisure purposes.
include stimulants, sedatives, hallucinogens and opioids.
each operates in a particular way, increasing or decreasing specific neurotransmitters at the synapse.

Question 38

3.1.2 what type of drug is cocaine?

Answer 38

a stimulant

has a stimulant effect on the brain’s reward pathway (the mesocorticolimbic pathway)

Question 39

3.1.2 how does cocaine effect the transmission process in the CNS?

Answer 39

cocaine blocks the reuptake of dopamine by binding with dopamine transporter molecules on the terminal buttons of the presynaptic neuron.
as cocaine prevents this process, the synapse is flooded with surplus quantities of dopamine, all available for binding with postsynaptic receptors.
this results in the euphoric ‘high’.

Question 40

3.1.2 what are the long-term effects of cocaine?

Answer 40

after repeated use, dopamine receptors become downregulated.
fewer receptors are active (some are damaged and shut down) and the quantity of dopamine produced declines.
this results in withdrawal (craving for the drug and higher doses need to get the same effects, tolerance).

Question 41

3.1.2 what type of drug is heroin?

Answer 41

an opioid with depressant effects.

slows down CNS activity.

Question 42

3.1.2 how does heroin effect the transmission process in the CNS?

Answer 42

once heroin reaches the brain most of it is processed into morphine.
morphine binds with a specific opioid receptor found at the synapse in the cerebral cortex, limbic system and hypothalamus.
it binds with the receptors of the natural opioid system to massively enhance the natural response of analgesics (painkillers).

Question 43

3.1.2 what is the difference between an agonist and antagonist drug?

Answer 43

heroin is an agonist drug because it mimics the action of another biochemical.
an antagonist drug stops the action or effect of another substance (e.g. naloxone).

Question 44

3.1.2 what are the long-term effects of heroin?

Answer 44

downregulation.
regular use of heroin means that opioid receptors on postsynaptic neurons are constantly binding with morphine molecules which desensitises them to the effect of the drug (tolerance).

Question 45

3.1.2 what is a strength of the explanations of the effects of recreational drugs?

Answer 45

supported by research using animals.
Weinshenker and Schroder deliberately damaged the mesocorticolimbic pathway in mice brains meaning neurons were unable to produce levels of dopamine usually associated with reward.
when this is done the mice fail to self-administer cocaine intravenously.
this does not occur when lesions are performed in other parts of the mouse brain.
this supports the view that cocaine’s effects are due to the activity of dopamine in the brain’s reward system.

Question 46

3.1.2 what is a weakness of the explanation of the effects of recreational drugs?

Answer 46

the problems using animal studies to understand drug effects on human CNS transmission.
the basic transmission process in mammals is similar but the human brain is much more complex.
isolating the effects of just one neurotransmitter greatly oversimplifies the process.
the interactions of dopamine with other neurotransmitter systems are not well understood.
therefore extrapolation from animals to humans should be undertaken cautiously.

Question 47

3.1.2 what is a competing argument of the explanation of the effects of recreational drugs?

Answer 47

evidence of drug effects on CNS transmission comes from studies of humans as well.
Nora Volkow used PET scans to track the activity of dopamine transporters in a cocaine induced ‘high’.
found that the extent to which cocaine occupied dopamine transporters correlated positively with the course of the subjective experience.
this supports the view that evidence from animal models are valid as human studies produce similar results.

Question 48

3.1.2 what is an application of the explanation of the effects of recreational drugs?

Answer 48

more treatments for addiction become available.
e.g. once heroin was identified as an agonist that binds to opiate receptors, other drugs were developed with a reverse mode of action.
naloxone is an antagonist drug that blocks opiate receptors and prevents morphine from occupying them.
can be used to help manage the withdrawal process and reduce symptoms.
this a treatment that developed from greater knowledge of the transmission effects of drugs.

Question 49

3.1.3 what is aggression?

Answer 49

aggression can be described as the intentional use of physical force or power, threatened or actual, against oneself, another person or against a group or community
aggression leads to violence

Question 50

3.1.3 describe the role of the limbic system (brain structure) as an explanation for aggression.

Question 51

3.1.3 describe the role of the prefrontal cortex (brain structure) as an explanation for agression.

Question 52

3.1.3 what is a strength for brain structure as an explanation for aggression?