biopsychology Flashcards
what is the nervous system?
network of cells in human body that allows communication
what are the two divisions of the nervous system?
central nervous system
peripheral nervous system
what are the two divisions of the central nervous system?
brain
spinal chord
what is the brain’s function in the central nervous system?
- processes information from senses
- conscious awareness
- higher mental functions
- emotion
- initiates responses
- stores memories
what is the spinal chord’s function in the central nervous system?
- conducts signals to and from the brain
- connects the nerves and the PNS
- responsible for reflex actions
what is the peripheral nervous system’s function?
sends messages to and from the CNS via neurones
what are the two divisions of the peripheral nervous system?
autonomic nervous system
somatic nervous system
describe the autonomic nervous system
- controls involuntary response
- controls smooth/cardiac muscles
- control centres located in the brainstem
describe the somatic nervous system
- controls voluntary movement
- controls skeletal muscles
- control centres located in the motor cortex
what are the 2 branches of the autonomic nervous system?
sympathetic
parasympathetic
what does the sympathetic branch control?
fight or flight response
what does the parasympathetic branch control?
restores bodily energy when relaxed
describe the structure of a neuron
dendrites
cell body
axon
myelin sheath
nodes of ranvier
terminal button
what is the function of the cell body in a neuron?
includes nucleus containing genetic material
what is the function of the dendrites of a neuron?
where the neurotransmitter receptors are found
what is the function of the myelin sheath of a neuron?
protects the axon
speed up transmission
what is the function of the nodes of ranvier?
speeds up transmission of impulse by making it ‘jump’ the gap
what is the function of the axon of a neuron?
sends nerve impulse through neuron to transmit the message
what is the function of the terminal button of a neuron?
releases neurotransmitters to transmit the message to the next neurone
what does a neuron do?
sends electrical and chemical impulses to communicate
what are 3 types of neuron?
sensory
relay
motor
where does the sensory neuron carry information to and from?
PNS to CNS
where does the relay neuron carry information to and from?
between the sensory and motor neurones
where does the motor neuron carry information to and from?
CNS to effector
what length dendrites and axons do all the neurones have?
sensory: long dendrites short axons
relay: short dendrites short axons
motor: short dendrites long axons
explain the process of synaptic transmission
- starts in the pre-synaptic neuron
- action potential sent down axon to terminal button
- neurotransmitters in vesicles released into synapse
- neurotransmitters diffuse across synapse and bind to receptor sites
where are the neurotransmitters only found?
in the pre synaptic neuron
where are receptors only found?
post synaptic neuron
after the neurotransmitters bind to the receptor sites, what happens?
next neuron gets ready to fire an impulse
OR
reuptake
what are the two types of neurotransmitter?
excitatory and inhibitory
what do excitatory neurons do?
- bind to the post synaptic neuron receptors
- post synaptic become positively charged
- making it more likely for the post synaptic neuron to fire an impulse
- increasing activity in the brain
what do inhibitory neurons do?
- bind to the post synaptic neuron receptors
- post synaptic become negatively charged
- making it less likely for the post synaptic neuron to fire an impulse
- decreasing activity in brain
what is summation?
- occurs when excitatory and inhibitory are added together
- if the effect is mainly inhibitory it makes it less likely for the neuron to fire an impulse
- if it is mainly excitatory the neuron will fire an impulse
what is the function of the endocrine system?
chemical system of communication in the blood stream that regulates activity of cells and organs
what are the chemical messages the endocrine system uses to communicate with?
hormones released by glands
what is a gland?
an organ that secretes hormones to control functions
what are 5 glands we need to know?
pituitary
adrenal
testes
ovaries
pineal
what is the pituitary gland sometimes known as?
master gland
what is the function of the pituitary gland?
secretes many different hormones that control functions of other glands
what is the function of the adrenal gland?
secretes adrenaline
causing changes like increased heart rate
in fight or flight response
what is the function of the pineal gland?
secretes melatonin
making a person tired
involved in sleep wake cycle
what are the ovaries and testes a part of?
anterior pituitary gland
what happens in the ovaries? (endocrine system)
anterior pituitary gland secretes LH and FSH
which stimulates the ovaries to release oestrogen and progesterone
regulating menstrual cycle
what happens in the testes? (endocrine system)
anterior pituitary gland releases LH and FSH
stimulating testes to release testosterone
producing male characteristics
what does the anterior pituitary gland secrete?
LH and FSH
what happens during the fight or flight response?
- stressor identified by hypothalamus
- adrenaline released by adrenal medulla into bloodstream
- fight or flight response
- produces a physiological reaction (increased heart rate)
- parasympathetic branch returns body to normal
what is the direct effect of adrenaline?
- increase heart rate
- increase blood pressure
-increase blood flow to brain
what is the indirect effect of adrenaline?
- prepares body for fight or flight
- increase blood supply to skeletal muscles
- stops digestion
- stops saliva production
- increase oxygen levels in brain
what does the parasympathetic branch do once the stressor has passed?
rest and digest
define localisation of function
specific areas of the brain are specialised for certain functions
(example)
define hemispheric lateralisation
brain is split into 2 symmetrical halves (left and right hemisphere)
different hemispheres are responsible for different mental processes
what is the holistic theory?
before localisation and lateralisation,
scientists believed all parts of the brain worked together when processing information
name 6 areas/cortexes of the brain
broca’s area
wernicke’s area
motor cortex
somatosensory cortex
visual cortex
auditory cortex
where are the 2 language areas of the brain located?
left hemisphere
where are the 4 cortexes of the brain located?
both hemispheres
what is the function of the broca’s area?
production of language
what does damage to the broca’s area cause?
broca’s aphasia (speech lacking fluency)
what is the function of the wernicke’s area?
understanding of language
what does damage to the wernicke’s area cause?
wernick’s aphasia (producing nonsense words/not understanding)
what is the function of the motor cortex?
creates voluntary movement
what does damage to the motor cortex cause?
lack of control over fine movements
paralysis
what is the function of the somatosensory cortex?
processes information from senses
what does damage to the somatosensory cortex cause?
problems perceiving touch
what is the function of the visual cortex?
receives information from the eyes
what does damage to the visual cortex cause?
blindness
hallucinations
what is the function of the auditory cortex?
analysing speech based information
what is the left hemisphere responsible for?
language
includes the broca’s area and the wernicke’s area
what is the right hemisphere responsible for?
recognition
creativity
emotional contexts
what is contralateral wiring?
- left hemisphere receives information from the right visual field and controls the right side of the body
- right hemisphere receives information from the left visual field and controls the left side of the body
what is synaptic pruning?
synaptic connections we don’t use regularly are deleted and ones we use regularly are strengthened
how old are we when the increase in the number of new synaptic connections is high?
infancy
how many new synaptic connections are made at 2-3 years old?
15,000
how can new synaptic connections be formed?
new experiences and learning
who researched into plasticity?
Maguire et al (2000)
explain research into plasticity
- brains of London taxi drivers were studied
- greater volume of grey matter in posterior hippocampus in more experienced taxi drivers
- because they had greater knowledge of the roads
- experience=platicity
what does the posterior hippocampus control?
spatial and navigational skills
what is functional recovery?
a type of plasticity that recovers abilities and mental processes that have been damaged
how does functional recovery work?
brain rewires itself by forming new synaptic connections close to the damaged area
what 2 things can functional recovery lead to?
axonal sprouting
recruitment of homologous areas
what is axonal sprouting?
growth of new nerve endings which connect with other undamaged nerve cells to form new pathways.
what is recruitment of homologous areas?
areas from opposite side of the brain take over the function of the damaged area of the brain
what 5 things affect recovery after trauma?
Perseverance
Age
Gender
Education
Stress/drugs/alcohol
how does perseverance affect recovery after trauma?
some people may appear to lose function but have stopped trying due to them believing that it is unrecoverable
how does age affect recovery after trauma?
younger people are more likely to recover after trauma compared to 40+ because of deterioration in the brain
how does gender affect recovery after trauma?
some research suggests that females are more likely to recover than males
how does education affect recovery after trauma?
- Schneider et al found that more time people with a brain injury had spent in education the greater their chance of a disability free recovery
- 40% of people who had DRF had more than 16 years’ education
- 10% had less than 12 years’ education
how does stress/alcohol/drugs affect recovery after trauma?
recovering takes effort to do so these factors would make the individuals lack motivation
what are the ways of studying the brain?
functional magnetic resonance imaging (fMRIs)
electroencephalograph (EEG)
event related potentials (ERP)
post mortems
how does functional magnetic resonance imaging work?
- identifies changes in oxygen levels in blood
- when a brain area is more active, more oxygen is used leading to increased blood flow
- produces an activation map (3D image)
how do electroencephalographs work?
- electrodes placed on the scalp using skull cap
- detect small electrical changes caused by brain activity
- electrical signals graphed over time to see a person’s general brain activity
how do event related potentials work?
- electrodes are placed on the scalp
- shows specific brain activity
- stimulus is presented to an individual many times and electrical signals graphed over time
- extraneous brain activity from the original EEG recording is filtered out leaving only responses that link to the stimulus (ERPs)
how do post mortems work?
- brain of dead patient is examined and dissected to check for abnormalities
- brain compared with a brain that does not show same behaviour
- used on people who have rare disorder
what are fMRIs used to identify?
which specific parts of the brain are active during mental processes
what are EEGs used to identify?
sleep/arousal states
used to diagnose epilepsy
what are ERPs used to identify?
types of brainwaves that are triggered by certain events
what piece of research used post-mortems?
Broca’s area
what are the 3 biological rhythms called?
circadian
infradian
ultradian
what are all biological processes controlled and influenced by?
controlled by endogenous pacemakers
influenced by exogenous zeitgebers
what is an endogenous pacemaker?
internal body clock
what is an exogenous zeitgeber?
external changes to environment
how long do the 3 types of biological rhythms last?
circadian: 24 hours
infradian: over 24 hours
ultradian: under 24 hours
what is an example of a circadian rhythm?
sleep wake cycle
describe the sleep wake cycle
- controlled by superchiasmatic nucleus in hypothalamus (endogenous pacemaker)
- eyes detect change in light due to less light received by retina
- message received by SCN which stimulates the pineal gland to release melanin and promote sleep
- SCN resets when eyes detect light which maintains the sleep wake cycle to 24h
what is an example of an infradian rhythm?
menstrual cycle
describe the menstrual cycle
- 28-35 days- starts on the day of period and ends on the day before next period
- pituitary gland releases FSH that stimulates release of oestrogen
- oestrogen causes egg to mature and develops womb lining
- oestrogen increase causes LH to increase
- LH promotes release of egg
- progesterone thickens womb walls
- if egg isn’t fertilised, egg is absorbed
- exogenous zeitgebers: stress, pheromones
what is an example of an ultradian rhythm?
stages of sleep
how long do the stages of sleep last and how many stages are there?
5 stages
lasts 90 minutes
what does a sleep staircase mean?
that a person can repeat the cycle up to 5 times a night in a rhythmic pattern
what are the 5 stages of the stages of sleep?
stage 1 and 2- light sleep NREM
stage 3 and 4- deep sleep NREM
stage 5- REM
describe stage 1 and 2 in the stages of sleep
- light sleep where they may be easily woken
Stage 1 = experience alpha waves
Stage 2 = alpha waves continue but random changes in pattern called sleep spindles happen
describe stage 3 and 4 in the stages of sleep
- deep sleep or slow wave sleep (SWS)
- delta brain waves with lower frequency and higher amplitude
- difficult to wake someone at this point
describe stage 5 of the stages of sleep
1.body is paralysed
2. brain activity closely resembles that of the awake brain
3. brain produces theta waves and the eyes occasionally move around (REM)
4. dreams often experienced in this stage
what way of studying the brain is used to study stages of sleeping?
EEG
