Biopsychology Flashcards
What is the nervous system
- a specialised network of cells
- our primary internal communication system
- 2 main functions : to collect,process and repsond to info AND to co-ordinate working of organs and cells
- split into two sub-systems
- the peripheral NS and the Central NS
Describe the central nervous system
- made up of the brain and the spinal chord
- the brain is the centre of all conscious actions and has an outer layer called the cerebral cortex which is what distinguishes humans from other animals
- spinal chord is an extension of the brain and is responsible for reflex actions
Describe the peripheral nervous system
- the PNS transmits messages to and from the CNS via millions of neurones
- further subdivided into 2 systems
1. autonomic NS - governs vital functions in body such as heart rate, breathing, digestion, sexual arousal
2. somatic NS - receives information from sensory receptors and controls muscle movement
What is the endocrine system?
- works alongside the nervous system
- instructs glands to release hormones directly into the bloodstream
Describe the actions of glands and hormones
- glands are organs responsible for synthesising hormones and releasing them into the bloodstream
- hormones are chemical substances that circulate the bloodstream and only affect target organs
Nmae two examples of glands in our body and what they are responsible for
THYROID - a gland in our throat responsible for releasing thyroxine
- thyroxine affects cells in the heart and cells throughout the body which affect metabolic rates
PITUITARY - a gland in our brain
- AKA the master gland as it controls the release of hormones from other glands in the body
How do the endocrine system and ANS work together in the fight or flight response
- when a stressor is perceived, the hypothalmus triggers activity in the sympathetic branch of the ANS
- ANS switches from parasympathetic state to sympathetic state
- adrenaline is release from adrenal medulla in adrenal glands
- causes physiological changes : getting body ready for fight or flght
- once stress passes, parasympathetic NS returns body to resting state
- the PNS works antagonistically to the SNS
- this is an AUTOMATIC response
Describe the sympathetic state
- heart rate increases
- blood pressure increases
- salivary production inhibited
- digestion inhibited
- pupils dilated
Deescribe the parasympathetic state
- digestion stimulated
- heart rate decreases
- blood pressure decreases
- pupils constricted
- salivary production continues
What is a sensory neurone?
- carry messages from PNS to SNS
What is a motor neurone?
- connected to an effector which brings about a response
Describe electrical transmission
- The resting potential of a neurone is negative
- when a stimulus activates the neuron, it becomes positively charged for a split second which causes an action potential to occur
- sending an electrical impulse down the axon
Describe synaptic transmission
- transmission between neurones is known as synaptic transmission
- synapses include the synaptic cleft, pre-synaptic terminal, post-synaptic receptor site
- when the action potential reaches the pre-synaptic terminal, it triggers the release of the neurotransmitter
Describe the actions of neurotransmitters
- neurotransmitters are chemicals that diffuse across the synaptic cleft
- they are released from the pre-synaptic terminal and they bind to post-synaptics receptor sites
Distinguish between excitatory and inhibitory
EXCITATORY - increases positive charge of the neuron once taken up by post-synaptic neuron
INHIBITORY - increases the negative charge of the post-synaptic neuron
Define localistation of function
The theory that different parts of the brain are responsible for different functions
What are the four different areas of the brain?
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Name the 6 different “areas”
What is the function of the auditory area (front temporal lobe)
- analyses speech-based information
- damage could lead to hearing loss
What is the function of Broca’s area (front of frontal lobe)?
- responsible for speech production
- damage (Broca’s aphasia) could result in slow, labourious speech that lacks fluency
What is the function of the Motor cortex (back of frontal lobe)
- responsible for voluntary movements
- damage could cause loss of control over fine movements
What is the function of the somatosensory area? ( front of parietal lobe)
- resposnsible for processing sensory information
What is the function of the visual cortex?
- Responsible for processing visual information from visual fields
What is the function of Wernicke’s area?
- responsible for language comprehension
- wernicke’s aphasia could result in nonsense language being produced
localisation strength - CASE STUDY
(+) Phineas Gage - frontal lobe damaged through a metal rod piercing it - still survived but personality changed to quick- temepered and rude etc suggesting that persoanlity and temperament are localised in the frontal lobe
HOWEVER
Case studies don’t have a before to compare to so the findings might not be valid and also can’t check reliability or generalize
Localisation strengths (research evidence)
(+) wealth of evidence supporting localisation - Peterson et al conducted brain scans and found Broca’s area to light up during reading tasks and Wernicke’s area during listening tasks - suggests these parts of the brain have different functions
localisation weaknesses
(-) plasticity supports a holistic view of brain - diff parts of brain can change function
(-) Lashley said that higher cognitive processes are not localised - removed parts (10%-50%) of cortex of mice and put them in maze and it was found no area was proven to be more important - suggests that higher functions like learning arent localised
What does Plasticity mean?
- The brain’s tendency to change and adapt in response to new learning and experiences
- during infancy we have the most synaptic pathways but as we grow some pathways are not used and thin down as a result
- but some are used more and therefore become stronger
- this is known as synaptic pruning
Describe the research done by Maguire et al
- Maguire et al studied the brains of London Cab drivers
- found a significant difference in sizes of the volume of the grey matter in the hippocampus between a control group and the London Cabbies
- the hippocampus is associated with spatial and navigational skills
Describe what Functional Recovery means
- its a form of plasticity
- following trauma or injury, unaffected areas of the brain can compensate for the damaged areas of the brain
- neuroscientists say that this happens very quickly after injury but can slow down and so patients have to undergo rehabilitative therapy
Describe HOW the brain recovers?
- the braincan rewire and reorganise itself by forming new synaptic connections
- done by:
- axonal spouting - growth of new nerve endings
- reformation of new blood vessels
- recruitment of homolgous areas on opposite hemisphere
plasticity + functional recovery strengths
(+) practical application - understanding of processes involved in plasticity contributed to neurorehabilitation - increased understanding of it so it can be used more effectively - increases validity
(+) research evidence from hubel and wiesel - sewed one eye of a kitten shut and anaylsed brain cortical activity - found that the visual cortex associated with the shut eye did not remain idle but processed information from the open eye - shows that cortical remapping does occur