Biopsychology Flashcards
What is the nervous system?
A specialised network of cells and our primary communication system
What is the nervous systems 2 main functions
To collect, process and responded information in the environment
To coordinate the working of different organs and cells in the body
What is the central nervous system?
It is made up of the brain and spinal cord
The brain is the centre of all consciousness awareness
The cerebral cortex of the brain = higher mental functions.
The spinal cord is an extension and is responsible for reflex actions
It passes messages to and from the brain and connects nerves to the PNS.
What is the structure of the PNS
Sub divided into into the autonomic and somatic
Autonomic governs vital functions in the body such as heart rate and breathing
The somatic controls muscle movement and receives information from sensory receptors.
The autonomic breaks off into the sympathetic and para sympathetic
What does the endocrine system do?
It controls vital functions through the use of hormones
It is slower than the CNS
What are glands function in the endocrine system
Glands are organs in the body that produce hormones
Putitry gland controls all other glands and is located in the brain
What is the hormones job in the endocrine system?
Hormones are secreted into the blood stream and affect any cell in the body that has a receptor for that particular hormone
Thyroxine produced by the thyroid effects cells in the heart and in the body that increase metabolic rate this effects growth hormones.
What is the flight or fight response?
Stress Hypothalamus Sympathetic branch Adrenaline Increased Hr and dilation of pupils Threat passes Parasympathetic branch Rest and digest
What are neurons
They work by transmitting signals electrically and chemically these provide the nervous system with the primary means of communication
Motor neurons
Sensory neurons
Relay neurons
What are motor neurons
They connect the CNS to effectors such as muscles and glands. They have short dendrites and long axons
What are sensory neurons
They carry messages from the PNS to the CNS they have long dendrites and short axons
What are relay neurons
They connect sensory to motor or other relay. They have short dendrites and short axons.
What is teh structure of the neuron
Cell body - genetic material of the cell
Dendrites- branch like structure that protrude from the cell body. These carry nerve impulses from neighbouring neurons to the cell body.
Axon - carries electrical signals away from the cell body it is covered in a fatty layer called the myelin sheath. Gaps in the axon called nodes of ravienier speed up transmission of the impulse.
Terminal buttons - at the end of the axon communicate with the next neuron in the chain across a gap called a synapse
What happens in electric transmission
When a neuron is in resting state the inside is negatively charged.
When a neuron is activated, the inside of the cell becomes positively charged for a split second causing an action potential to occur
It creates an electrical impulse to travel down the axon towards the end of the neuron.
What is a synapse
Each neuron is separated from the next by a gap
What is a chemical transmission
Signals between neurons are transmitted chemically across the synapse.
When the electrical impulse reaches the end of the neuron it triggers the release of neurotransmitter from the synaptic vesicles. It travels the gap and then is taken up by the post synaptic transmitters
The chemical message is then turned back into electrical impulses
What are neurotransmitters
They are chemicals that diffuse across the synapse to the next neuron
They each have their own specific molecular structure that fits perfectly into the post synaptic receptor.
E.g seretonin
What is excitation and inhibition?
Excitation - more positive charges, making the neuron willing to fire. E.g adrenaline
Serotonin - increases negative charge making it less likely to fire e.g seretonin
What is summation
Excitory and inhibitory influences are summed and must reach a certain threshold in order for the action potential of the post synaptic neuron to be triggered.
AO1 for localisation of function in the brain
The left side of the brain is in control of the right side of the body and vice versa
The cerabel cortex lines the brain and makes the brain more highly developed
There is 2 hemispheres which are then divided into 4: frontal, parietal, occipital and temporal.
Motor area
Somatosensory area
Visual area
Auditory area
Bro as area
Wernickes area
AO1 for localisation of function in the brain - motor area
Back of frontal lobe
Voluntary movement
AO1 for localisation of function in the brain - somatosensory area
The front of the parietal lobes
Sensory information
AO1 for localisation of function in the brain - visual area
Occipital lobe at the back
Visual Feild
Opposites
AO1 for localisation of function in the brain - auditory area
Temporal lobe
Analyses speech
AO1 for localisation of function in the brain - brocas area
Left frontal lobe
Speech production
AO1 for localisation of function in the brain - wrenickes area
Back of temporal lobe
Language comprehension
AO3 for localisation of function in the brain
STRENGTH- brain scan evidence
STRENGTH- research support do retry et al OCD patients, cingulate glyrus removed 1/3 didn’t have OCD anymore
STRENGTH - Gage, pole, change of personality
LIMITATION - neural plasticity
Split brain research - A01
Hemispheric lateralisation Sperry - disconnected the brain in epileptic patients to sop seizures. He then ran a procedure where he projected an image or word to a patients to RVF (processing LH) and another to the LVF (RH) The information cannot be shared RVF - describes what is seen LVF- nothing there.
Split brain research - AO3
STRENGTH- shows lateralisation
STRENGTH - standardised
LIMITATION - generalisation
STRENGTH - started a debate
Ways of studying the brain - AO1
Ways of studying the brain are usually used for medical purposes and diagnosis In psychology it's for localisation FMRI EEG ERPs Post Mortem
ways to study the brain - FMRI
Detects changes in blood oxygenation and flow that occur due to neural activity in specific brain areas
When a brain area is more active it consumes more oxygen and therefore blood flow is directed to the active area
Produces 3D image
- EEG
Measures electrical activity within the brain via electrodes using a skull cap
The scan recording represents the brain wave patterns generated from millions of neurones. To show overall brain activity.
Used for epilepsy
- ERPs
Event related potentials are what is left when all extraneous brain activity is filtered out of an EEG.
- Post mortems
A technique involving the analysis of someone’s brain once they have died
Ways to study the brain - AO3
STRENGTH - FMRI is non invasive, doesn’t use radiation
LIMITATION - FMRI is expensive
STRENGTH - EEG are invaluable in diagnosing disorders such as epilepsy.
STRENGTH - post mortems have always been around
Circadian rhythms - what are they?
Biological rhythms are periodic activity, governed by:
Internal body clock (endogenous pacemakers)
External changes in the environment (exogenous pacemakers)
Circadian rhythms last 24 hours
Circadian rhythms - sleep wake cycle
Exogenous zeitgebers - the fact we feel drowsy when it’s nighttime and alert during the day shows the effect of daylight
Endogenous pacemakers - a biological clock ‘left to its own devices’ without the influences of external stimuli
There is a basic rhythm governed by the suprachiasmatic nucleus, which lies just above the optic chiasm and receives information about light.
The exogenous zeitgeber (light) can reset the SCN.
Circadian rhythms - siffres research
He spent long periods of time in dark caves to examine the effects of free running biological rhythms. Two months (1962) and 6 months (1970).
Siffres free running circadian rhythm settled to 25 hours
He did have a regular sleep wake cycle
Circadian rhythms - AO3
STRENGTH - practical application to drugs, better times they effect you.
LIMITATION - small sample
LIMITATION - extraneous variables, artificial light
LIMITATION - individual difference, ages, morning or night person
Endogenous pacemakers and exogenous zeitgebers - what does the SCN do?
The SCN is a small bundle of nerve cells in the hyperthalamus which helps maintain circadian rhythms.
It lies just above the optic chiasm and receives information about light from this structure.
DeCoursey et al destroyed the SCN in 30 chipmunks and then returned them to their natural habitat and observed them for 80 days. Their sleep/wake cycle and many were killed by predators.
Ralph et al bred mutant hampsters with 20 hour sleep/wake cycles. SCN cells were transplanted from the feotal tissue of these hamsters to normal hamsters and they to developed 20 hour sleep wake cycles.
SCN passes information on a day length to the pineal gland which increases the production of melatonin during the night.
Endogenous pacemakers and exogenous zeitgebers - ex zeitgebers and the sleep/ wake cycle
Zeitgebers reset the biological clock for sleep/wake cycle and interaction of internal and external factors.
Light can reset the SCN
Campbell and Murphy woke 15 participants at various times and shine a light in the back of their knees - producing a deviation in the sleep/wake cycle of up to 3 hours light is a powerful ex zeitgebers detected by skin receptors and does not necessarily rely on eyes.
Sleep wake cycle is pretty random in baby’s up to 6 weeks
Endogenous pacemakers and exogenous zeitgebers - AO3
LIMITATION - animals ethics
LIMITATION - animals generalisability
LIMITATION - Campbell’s research hasn’t be replicated there may have been extraneous light
Limitation - they work together, siffres study is unrealistic, isolating them
Infradian rhythms and ultradian rhythms - infradian rhythms
Menstrual cycle 28 days
Less than one cycle a day so it happens in a 28 day period
Stern and McClintock studied 29 women with irregular periods. Pheromones were taken at different stages of their cycle, via a cotton pad under the arm pits. This was then rubbed on the upper lips of another participant, their cycle then adapted to odour donor.
Seasonal effective disorder occurs in winter months when there is a lack of light. It is circannual cycle. Melatonin more will be produced as is darker.
Infradian rhythms and ultradian rhythms - Ultradian rhythms
Sleep patterns = 90 mins
They happen more than a 24 hour cycle do they are more than ultradian
Stage 1 and 2 is light sleep, person is easily woken, brain waves are slower.
Stage 3 and 4 deep sleep, hard to wake, brain waves are even slower.
Stage 5 REM sleep, fast jerky activity in eyes. Body paralysed yet brain activity speeds up.
Infradian rhythms and ultradian rhythms - A03
LIMITATION - period research could be confounding variables such as diet.
STRENGTH - SAD practical application, light box
Strength - quality of research, REM supported by another study which links with dreaming if participants were woken they could recall dreams it is a distinct ultradian rhythm.
LIMITATION - individual differences, insomnia.
