biopsychology ao1 Flashcards
psychology paper 2
what is central nervous system?
brain centre for all conscious awareness and brain is divided into 2 hemispheres
what is peripheral nervous system?
made up of nerves outside the CNS allows sensory information to be recieved by whole body
what is somatic nervous system?
- sensory neuron relay message to CNS
- motor neuron relay message from CNS to body
- allow body to make conscious muscle movements
- involved in reflex actions
what is autonomic nervous system?
- controls automatic processes
- transmit info to and from internal organs
- involuntary responses heartbeat etc
- made up of motor pathways
what are two parts of autonomic nervous system?
sympathetic and parasympathetic
structure of neuron?
cell body
dendrites
axon
what is sensory neuron function?
carry nerve impulse from sensory receptors to the CNS
some neuron terminates at spinal cord producing reflex action
what is relay neuron function?
go between sensory and motor neurones allowing them to communicate
what is role of motor neuron?
nerve impulse from CNS to control muscle and glands (control muscle contraction etc)
what is the process of synaptic transmission?
- action potential travels down axon to neuron
- presynaptic neuron release vesicles into synaptic gap (contain neurotransmitters)
- neurotransmitters diffuse through synaptic gap into post synaptic membrane
- bind to receptors
what are excitatory neurotransmitters and examples?
make post synaptic membrane more likely to fire eg acetylcholine/adrenaline
what are inhibitory neurotransmitters and examples?
make post synaptic membrane less likely to fire eg GABA/serotonin
what is summation?
if the total excitatory signals reach a threshold causing neuron to more likely fire
what is the endocrine system?
network of glands that manufacture and secrete hormones (produced by endocrine glands)
what are hormones?
chemicals that circulate bloodstream and carried to target sites around body
what is the pituitary gland?
produces hormones that influence release of other hormones from other glands (master gland)
what are the two adrenal glands?
adrenal cortex and adrenal medulla
what does adrenal cortex produce?
cortisol
what does adrenal medulla produce?
adrenaline
what are ovaries and what do they produce?
part of female reproductive system and produce oestrogen/progesterone
what are testes and what do they produce?
part of male reproductive system and produce testosterone
what is the fight or flight response?
- amygdala detects situation
- sends signal to hypothalamus which communicates with rest of body through SNS
- sends signal to adrenal medulla
- that releases adrenaline
- adrenaline circulates body
- threat passed PNS reverses changes
what are changes to body when in fight or flight?
- increased heart rate
- increased breathing
- pupil dilation
- reduction of nonessential functions
what is localisation vs holistic theory?
brain is made of connected areas that do specific functions or brain works together
what is motor cortex?
responsible for generating motor movements (each side responsible for opposite side of body)
what is somatosensory cortex?
produces sensations from touch pressure pain and temperature
what is visual cortex?
detects visual information (each side controls opposite side of body)
what is auditory centres?
recognise sounds and analyse speech based information
what is brocas area?
- area for speech production found by broca who studied patients who can understand language but not speak it
- damage causes brocas aphasia
what is wernickes area?
- area for understanding language/sounds and putting meanings by wernicke who studied patients who could speak but not understand language
- damage causes wernickes aphasia
what is hemispheric lateralisation?
- two sides of brain not completely alike
- brain function specialised to different sides eg language and speech production found left side dominate
- connected by corpus callosum
what are split brain patients?
- surgery helped patients with severe epilepsy
- involved cutting corpus callosum
- hemispheres could no longer communicate
what was split brain patient research?
- patients would have image shown on right visual field (controlled by left) or left visual field (controlled by right)
- information can only be seen by one hemisphere for both fields
what was sperrys split brain reseaech findings?
- ppts could describe what they saw from right visual field (controlled by left)
- but when asked to match faces to pictures right hemisphere was dominant
- left = speech language
- right = facial recognition visuals
what is plasticity?
brains ability to change and adapt as a result of experience and learning eg cognitive pruning brain connections not used often are deleted through this
what is research into plasticity?
- researcher studied brain of london taxi drivers and compared to control group
- found more grey matter in posterior hippocampus for taxi drivers than control
- brain part linked with spatial and navigational skills = shows plasticity
what is functional recovery?
- after injury unaffected parts of brain are able to adapt and compensate tho ares that were damaged
- example of neural plasticity
what is axonal sprouting?
new nerve endings grows and connects with undamaged nerve cells to provide new nerve pathways
what is unmasking pathways?
form new synaptic connections near damaged area and secondary neural pathways start to function
what is neural reorganisation?
recruitment of similar areas onto opposite hemisphere
what was Tajiris research into functional recovery?
- randomly assigned rats with traumatic brain injury into 2 groups
- one group received transplant of stem cells into that region of injury and second group didn’t
- after 3 months brain injury in stem cell rats showed development of neurone like cells but control didn’t
- stem cells produced new cells in damaged area
what is functional magnetic resonance imaging fMRI?
- detect change in blood oxygenation and flow that occurs in brain
- shows 3D images of brains using more oxygen so therefore more active
what is electroencephalogram EEGs?
- electrical activity in brain via electrodes fixed onto scalp
- scan represents brainwaves from neurons
- used as diagnostic tool
what is event related potentials ERPs?
- use EEG date but isolate specific neural responses associated with sensory motor or cognitive events
- these statistical averaging techniques filter out extraneous brain activity leaving only specific responses to specific stimulus (ERPs remain)
what is post mortem examination?
- analysis of ones brain after death (done on those with disorders etc)
- areas of damaged analysed after death
- compared to neurotypical brain to see difference
what is a circadian rhythm?
lasts about 24 hours eg sleep wake cycle
what is siffres study on sleep wake cycle?
- siffre spent several periods underground to study biological rhythms
- isolated from natural light
- each time his free running bio rhythm settled to 25 hours he continued to sleep on regular schedule
- similar results found by other researchers found cycles of 24 to 25 (extended one of 29)
- suggests natural circadian rhythm longer ran 24 hours and entrained by EZ to fit 24 hours
what is infradian cycle?
lasts longer than a day eg menstrual cycle
what is research into infradian rhythms?
- researchers wanted to see if menstrual cycle affected by exogenous factors
- control group wore alcohol soaked pad under armpit
- pheromones were rubbed top lip of another woman and their cycles were monitored
- 69% of cycles were shown changes in timings brought closer to cycles of ppts in control
- supports role of exogenous zeitgebers in infradian cycle
what is ultradian rhythm?
shorter than a day eg 90 min cycle of sleep (stages 1 to 4 then REM sleep then reversed again)
what is research into ultradian rhythms?
- monitored electrical activity in brains of 9 ppts during sleep using EEG recordings
- woke ppts in different stages of sleep
- people awakened during REM stage said dreaming 90% of time only 7% led to dream recall
- supports stages of sleep esp REM sleep in dreaming
what are endogenous pacemakers?
- internal body clock regulates our biological rhythm
what is example of endogenous pacemaker?
pineal gland
SCN sends signals to pineal gland when light sensed production of melotonin prohibited
light = low melatonin = wake up vice versa so regulates sleep wake cycle
what is research into endogenous pacemakers?
- siffres study shows that free runnings EPs without influence of EZs arent successfully entrained to 24 hour cycle -> shows importance of EZs
- research into mutant hamsters who had abnormal circadian rhythms that lasted 20 hours
- SCN neurons implanted from mutant to normal hamsters
- normal hamsters took 20 hour rhythm indicating SCN (EP) plays essential role in regulating circadian rhythm
what is exogenous zeitgebers?
external factor that entrains our biological rhythms without this EPs would go free running
what is an example of exogenous zeitgebers?
light
if our clock running slow because sun rises earlier than day before
morning light shifts the clock ahead so synchronised with outside world
called entrainment
what is research into exogenous zeitgebers?
- researchers woke 15 people up various times and light was shone at back of the knee
- some people experienced deviations of their sleep wake cycle by 3 hours
- light is a powerful exogenous zeitgeber
- shows light can entrain rhythms through skin receptors not only through eyes
interaction between EPs and EZs
EPs and EZs work together
our EPs like SCN are entrained by EZs like natural light meaning our cycle is regulated to adapt to changing seasons and day lengths etc
another example of EPs and EZs
SCN (EP) and social cues (EZ)
