Biopsychology Flashcards
Outline the structures and processes involved in synaptic transmission. (6 marks)
The synaptic cleft; pre and postsynaptic membranes; postsynaptic receptor sites, neurotransmitters in vesicles in the presynaptic terminal, release of neurotransmitters into the synaptic cleft when stimulated by nerve impulses (action potentials) arriving at the presynaptic terminal, combination of neurotransmitters with postsynaptic receptors;
POSTSYNAPTIC EFFECTS EITHER EXCITATORY (DEPOLARISATION) OR INHIBITORY (HYPERPOLARISATION).
Using an example, explain what is meant by the fight or flight response. (3 marks)
- Reference to perceived threatening / stressful situation (could be through definition or example).
- Reference to physiological change.
- Example of response / action.
Outline one difference between the EEG and ERPs. (2 marks)
EEG is a recording of general brain activity usually linked to states such as sleep and arousal, whilst ERPs are elicited by specific stimuli presented to the participant.
Using your knowledge of endogenous pacemakers and exogenous zeitgebers, explain the disruption of biological rhythms bcs of shift work
- Endogenous pacemakers – internal biological rhythms
- Exogenous zeitgebers – external factors, eg light
- Moving to night shift means pacemakers try to impose inbuilt rhythm of sleep, but are now out of synchrony with the zeitgeber of light
- Disruption of biological rhythms has been shown to lead to disrupted sleep patterns, increased anxiety and decreased alertness and vigilance.
Outline the fight or flight response.
- hypothalamus prepares the body for action/emergency response.
- involves the release of adrenaline (from the adrenal gland/medulla).
- Triggers/activates/switches from parasympathetic to sympathetic activity and back again.
- direct effects of adrenaline, eg increase heart rate – constricts blood vessels, increasing rate of blood flow and raising blood pressure – diverts blood away from the skin, kidneys and digestive system – increases blood to brain and skeletal muscle – increases respiration and sweating.
Identify the two components of the peripheral nervous system, and explain two differences in their organisation and/or functions
- the somatic nervous system (SNS) and the autonomic nervous system (ANS)
- The SNS has sensory and motor pathways, while the ANS is purely motor;
- The ANS controls internal organs and glands of the body while the SNS controls skeletal muscle, movement etc;
- ANS control centres are in the brain stem whilst SNS carries commands from the motor cortex.
Josie is twelve. Last year she was involved in a serious road accident and suffered head injuries that caused problems with speech and understanding language. Now, a year later, Josie has recovered most of her language abilities.
Using your knowledge of plasticity and functional recovery of the brain after trauma, explain Josie’s recovery.
- When the brain is still maturing recovery from trauma is more likely. Josie is young.
- Transfer of functions to undamaged areas (‘neural reorganisation’) which can explain her recovery.
- Growth of new neurons and/or connections to compensate for damaged areas (‘neural regeneration’) which can explain her recovery.
- Plasticity allows the brain to cope better with ‘indirect’ effects of brain damage eg swelling, haemorrhage following road accident.
Synaptic transmission
- Transmission involves impulses crossing a space or gap between an axon terminus and the adjacent neuron (the synapse/synaptic cleft)
- Neurotransmitters are chemicals released from vesicles on the presynaptic neuron
- They travel/diffuse across the synapse and lock onto receptor sites on receiving/postsynaptic neuron
- Some neurotransmitters increase the rate of firing in the receiving neurons and others decrease the rate of firing
- Psychoactive drugs work by affecting (increasing or inhibiting) the transmission of neurotransmitters across the synapse
Explain the process of synaptic transmission.
- electrical impulses (action potentials) reach the presynaptic terminal
- electrical impulses (action potentials) trigger release of neurotransmitters (or named example)
- neurotransmitters cross the synapse from vesicles
- neurotransmitters combine with receptors on the postsynaptic membrane
- stimulation of postsynaptic receptors by neurotransmitters result in either excitation (depolarisation) or inhibition (hyperpolarisation) of the postsynaptic membrane.
Lotta worries that because of her grandmother’s age she will not be able to make any recovery.
Using your knowledge of plasticity and functional recovery of the brain after trauma, explain why Lotta might be wrong.
- Lotta’s grandmother might still be capable of functional reorganisation/plasticity
- functional compensation by other undamaged areas
- although she is older her brain might still be able to form new connections (axons and dendrites) between neurons
- neuronal loss may be compensated for by regeneration (axon sprouting)
- denervation supersensitivity to reduce the severity/extent of Lotta’s grandmother’s impairment
- plasticity allows the brain to cope better with ‘indirect’ effects of brain damage resulting from inadequate blood supply following a stroke
- references to increased brain stimulation of the opposite hemisphere, physiotherapy, etc to enhance Lotta’s grandmother’s recovery
Outline the role of adrenaline in the fight or flight response.
- Adrenaline is released from the adrenal medulla in response to activation of the sympathomedullary pathway.
- Adrenaline has a range of effects on the body
•Direct effects of adrenaline
– increase heart rate
– constricts blood vessels, increasing rate of blood flow and raising blood pressure
– diverts blood away from the skin, kidneys and digestive system
– increases blood to brain and skeletal muscle
– increases respiration and sweating
•The general effects of adrenaline
– prepare the body for action, fight or flight,
– increase blood supply/oxygen, to skeletal muscle for physical action
– increase oxygen to brain for rapid response planning
Robert suffered a stroke at the age of 55. After the stroke he was paralysed down his right side, though he could move his left arm and leg easily. Robert could clearly understand what was said to him, but was unable to produce any speech.
Discuss how knowledge of hemispheric lateralisation and language centres in the brain has helped our understanding of cases such as Robert’s.
Refer to Robert’s case in your answer
The presence of a right sided paralysis confirms that in cases such as Robert’s there is lateralised damage to the left hemisphere
Robert, can understand speech so we conclude that he does not have Wernicke’s, receptive, aphasia; caused by damage to Wernicke’s area in the left hemisphere.
Robert cannot produce speech so we conclude that Broca’s area has been damaged leading to Broca’s, production or expressive aphasia.
Outline one difference between the EEG and ERPs
EEG is a recording of general brain activity usually linked to states such as sleep and arousal,
whilst ERPs are elicited by specific stimuli presented to the participant.
Sam is a police officer. She has just started working the night shift and after a week, she finds that she has difficulty sleeping during the day and is becoming tense and irritable. Sam is also worried that she is less alert during the night shift itself.
Using your knowledge of endogenous pacemakers and exogenous zeitgebers, explain Sam’s experiences.
- endogenous pacemakers – internal biological rhythms
- exogenous zeitgebers – external factors, eg light
- moving to night shift means pacemakers try to impose inbuilt rhythm of sleep, but are now out of synchrony with the zeitgeber of light
- disruption of biological rhythms has been shown to lead to disrupted sleep patterns, increased anxiety and decreased alertness and vigilance.
Outline the structures and processes involved in synaptic transmission.
the synaptic cleft; pre and postsynaptic membranes; postsynaptic receptor sites, neurotransmitters in vesicles in the presynaptic terminal, release of neurotransmitters into the synaptic cleft when stimulated by nerve impulses (action potentials) arriving at the presynaptic terminal, combination of neurotransmitters with postsynaptic receptors; postsynaptic effects either excitatory (depolarisation) or inhibitory (hyperpolarisation).
