biopsychology Flashcards
what two subdivisions is the NS divided into
- central ns
- peripheral ns
CNS
- consists of brain and spinal cord
- collects and processes sympathetic ns and responds to stimuli in the environment and coordinates working of different organs in the body
PNS
- relays messages (nerve impulses) from CNS to rest of body
what is the PNS divided into
somatic ns
autonomic ns
ANS
- important in homeostasis: maintains internal processes like bodily temperature, heart rate and blood pressure
- consists of motor pathways and 2 subcomponents
SNS
- maintains communication between CNS and outside world
- made up of sensory receptors that carry info to spinal cord, brain and motor pathways.
- provides muscle responses via motor pathways
what is the endocrine system
- a network of glands across the body that secretes hormones through the blood
glands that are a part of the endocrine system
- pineal
- thyroid
- ovaries
- testes
- adrenal gland (medulla)
- adrenal gland cortex
- hypothalamus
- pituitary
pineal gland
- secretes melatonin,
- sleep wake cycle
thyroid gland
- secretes thyroxine
- regulates metabolism
ovaries
- secretes oestrogen
- regulates female reproduction
testes
- secretes testosterone
- development of male sex characteristics
adrenal gland (medulla)
- secretes adrenaline and noradrenaline
- adrenal gland cortex
- secretes cortisol
- stimulates release of glucose
hypothalamus
- stimulates release of hormones from pituitary gland
pituitary gland
- master gland
- hormones released from here
- controls and stimulates other glands
process of stimulating a fight or flight response
- hypothalamus triggers ANS (sympathetic branch)
- ANS stimulates adrenal medulla
- adrenaline and noradrenaline to be released into the blood
- fight or flight response triggered
structure and function of motor neurons
- short dendrites, long axons
- connects CNS to receptors
- found in PNS and controls muscle movement
structure and function of relay neurons
- short dendrites and axons
- connects sensory and motor neurons
- allows fast reflex responses by bypassing the brain
structure and function of sensory neurons
- long dendrites, short axons
- found in receptors
- not all sensory receptors reach brain
firing of a neuron process
- neuron at resting state = negatively charged
- when neuron activated by a stimulus, inside of cell becomes positively charged for a split second
- action potential will pass through the neuron when positively charged
- allows an electrical impulse to move through the neuron
synaptic transmission
method of neurons communicating with each other
process of synaptic transmission
- vesicles release neurotransmitter into synaptic cleft
- neurotransmitters bind to receptors and activates them
- excess neurotransmitters are taken up by presynaptic neuron
- enzymes released to break down remaining neurotransmitters
- vesicles replenished with new and reused neurotransmitters
what are neurotransmitters
- chemical messengers in the body: transmit signals
- found in brain and spinal cord
- across synaptic cleft
neurons can either have a _ effect or _ effect on a neighbouring neuron
- excitory or inhibitory
excitation
- increases likelihood of happening
- adrenaline causes excitation by increasing a neuron’s positive charge and makes it more likely to fire
inhibition
- decreases likelihood of happening
- seratonin causes inhibition in neighbouring neuron, causes it to be charge, less likely to fire
summation
- addition of inputs
2 types of summation
spatial
temporal
spatial summation
- 2 or more inputs arrive from different presynaptic cells to same synapse at same time
temporal summation
- 2 or more action potentials arrive in rapid succession along a single presynaptic neuron
localisation is
each area of the brain has a specific function
motor cortex
region of frontal lobe involved in regulating voluntary movement
somatosensory cortex
area of parietal lobe that processes sensory information such as touch
visual cortex
part of occipital lobe that receives and processes visual information
auditory cortex
located in temporal lobe, analysis of speech based information
Broca’s area
area of frontal lobe of brain in the left hemisphere - responsible for speech production
Wernicke’s area
area of temporal lobe in left hemisphere - language comprehension
case study to support localisation of function
unique cases of neurological damage support the idea of localisation of function e.g phineas gage:
- tamping iron pole through his head
- took most of his left front lobe
- he used to be calm but after the accident he was short tempered and rude
- this suggested that the frontal lobe may be responsible for regulating mood.
evaluation of phineas gage
good:
- they are able to help more people that have similar injuries to Phineas Gage and are able to predict the changes to behaviour when a part of the brain was damaged.
- this makes the study more applicable.
bad:
- this is a case study that they did only on Phineas Gage.
- which would make the chances of someone having the same type of damage very low, therefore the study lacks generalisability.
brain scan evidence to support localisation of function
peterson et al 1988:
- used brain scans to show how Wernicke’s area was active during a listening task and Broca’s area during a reading task - suggests these areas of the brain have different functions
tulving et al:
- semantic and episodic memories reside in different parts of the prefrontal cortex
these studies support the idea of localisation of function theory. in addition, these provide scientific evidence of localisation of function which improves the validity of this concept
neurological evidence to support localisation of function theory
surgically removing or destroying areas of the brain to control aspects of behaviour was developed by Walter Freeman - however they were imprecise and unreliable
- dougherty et al reported on 44 OCD patients who had a ‘cingulotomy’ (lesioning of cingulate gyrus) . at a 32 week follow up, 1/3 of the patients met the criteria for a successful response to the surgery and 14% with a partial response
success of these procedures strongly suggests the symptoms and behaviours associated with serious mental disorders are localised