Biopsychology Flashcards
what is the nervous system?
the primary internal communication system, it is made up of the central nervous system (CNS) and the peripheral nervous system (PNS).
what is the central nervous system?
it is made up of the brain and the spinal chord.
what is the role of the brain?
the central control centre, it processes sensory information and controls motor and cognitive functions.
what is the role of the spinal chord?
an extension of the brain, it passes messages to and from the brain and connects nerves to the PNS, also responsible for reflex actions.
what is the peripheral nervous system?
it transmits messages via neurons to and from the CNS and is subdivided into the somatic nervous system (SNS) and the autonomic nervous system (ANS).
what is the role of the somatic nervous system?
controls muscle movement and receives information from sensory receptors.
what is the role of the autonomic nervous system?
regulates vital functions of the body e.g. breathing, heart rate, digestion etc. it has two main divisions: the sympathetic nervous system and the parasympathetic nervous system.
what does the sympathetic nervous system do?
prepares the body for a ‘fight or flight’ response in stressful situations, e.g. increased heart rate / breathing rate, dilates pupils, inhibits digestion / saliva production.
what does the parasympathetic nervous system do?
regulates the body back to its normal state after the stressor is gone e.g. decreases heart rate / breathing rate, constricts pupils, stimulates digestion / saliva production.
describe the divisions of the nervous system.
what is the endocrine system?
one of the body’s major information systems and in charge of slower bodily processes such as cell growth, it is made up of hormones and glands.
what is the role of hormones?
chemical messengers - transferring information and instructions from one set of cells to another.
what is the role of glands?
produces the hormones e.g. hypothalamus, pituitary gland, adrenal gland, thyroid gland etc.
what does the hypothalamus do?
the part of the brain that controls the endocrine system, it is connected to the pituitary gland and tells it to release hormones.
what does the pituitary gland do?
it is the ‘master gland’ in the brain that controls release of hormones around the rest of the body.
- in posterior, releases oxytocin for contractions in childbirth.
- in anterior, releases adrenocortical trophic hormone (ACTH) for stimulation of adrenal cortex and releases cortisol during stress.
what does the adrenal gland do?
- in the adrenal medulla, releases adrenaline and noradrenaline which are the key hormones for the ‘fight or flight’ response.
- in the adrenal cortex, releases cortisol to stimulate the release of glucose to provide the body with energy.
what does the thyroid gland do?
releases thyroxine for regulating metabolism.
what do the endocrine system and autonomic nervous system work together for?
to produce certain effects in the body e.g. the fight of flight response.
how do the endocrine system and the ANS work together for the ‘fight or flight’ response?
when a person perceives a situation as stressful, the sympathetic branch of the ANS is triggered and the stress hormone adrenaline is released in response, leading to physiological changes (increased heart rate, sweating, and so on), this state of arousal in the system is known as the ‘sympathetic’ state. Once the perceived stressor passes, the ‘parasympathetic’ branch of the ANS returns the body to normal, reducing the effects and activity of the sympathetic branch.
what are neurons?
nerve cells which transmit messages chemically and electrically (vary in size but they have the same structure).
what are the three types of neurons?
motor, sensory and relay
what is the role of the motor neuron?
connects the CNS to muscles and glands.
what is the role of the sensory neuron?
carries messages from the PNS to the CNS.
what is the role of the relay neuron?
connects sensory neurons to motor and other relay neurons.
what is the structure of neurons?
they vary in size, but all have the same structure; a cell body (soma), nucleus branches (dendrites), the axon, myelin sheath, nodes of ranvier, axon terminals.
what does the cell body (soma) do?
contains the nucleus.
what does the nucleus do?
contains the genetic material of the cell.
what do dendrites do?
carry nerve impulses from neurons to the cell body. (away from synapse)
what does the axon do?
carries the impulses away from the cell body down the length of the neuron. (towards synpase)
what does the mylein sheath do?
it protects the axon and speeds up electrical transmission of the impulse.
what do the nodes of ranvier do?
speed up transmission by forcing it to ‘jump’ across gaps along the axon.
what do the axon terminals do?
communicate with the next neuron in the chain across the synapse.
desrcibe the structure and function of a neuron.
neurons transmit messages chemically and electrically, they vary in size but all have the same structure. They have a cell body (soma), containing genetic material, of the cell (the nucleus) and branches (dendrites) which carry nerve impulses from neurons and carry functional information to the cell body. The axon carries impulses away from the soma, down the length of the neuron. The axon is covered in a protective layer known as the myelin sheath, which speeds up electrical transmission of the impulse. This effect is achieved by making the impulse ‘jump’ between gaps in the myelin sheath - these gaps are known as the nodes of ranvier. At the end of the neuron are axon terminals which allow for communication with adjacent neurons in the chains across the synapse.
what is a synapse?
the gap between neurons (chemical transmissions via neurotransmitters).
what are neurotransmitters?
chemicals that diffuse across the synapse to the next neuron in the chain.
what is synaptic transmission?
the process where neighbouring neurons communicate with each other by sending chemical messages across the synapse that separates them: signals with neurons are transmitted electrically while signals between neurons are transmitted chemically.
an electrical impulse reaches the end of a neuron (pre-synaptic cell) and triggers the release of neurotransmitters from tiny sacs called synaptic vesicles, which crosses the synapse and enters the receptor sites on the dendrites of the next neuron (the post-synaptic cell), where the chemical message is converted back into an electrical impulse and the process of transmission begins again in another neuron.
what are two types of neurotransmitters?
excitatory and inhibitory
what do excitatory neurotransmitters do?
stimulate the brain e.g. adrenaline.
what do inhibitory neurotransmitters do?
calm the brain and help create balance e.g. serotonin.
what is excitation?
the neurotransmitters excite the next neuron which produces an action potential e.g. adrenaline causes excitation of post-synaptic neuron which increases positive change and more likely to fire.
what is inhibition?
these neurotransmitters stop an action potential e.g. serotonin cause inhibition in the receiving neuron which makes it more negatively charged and less likely to fire.
what is summation?
the firing of post-synaptic neurons are decided by summation, a nerve cell can receive both excitatory post-synaptic potentials (EPSPs) and inhibitory post-synaptic potentials (IPSPs) simultaneously; the EPSPs and IPSPs are summed and if the net effect on the post-synaptic neuron is inhibitory then the neuron will be less likely to fire (negatively charged) and if the net effect is excitatory then the neuron will be more likely to fire (positively charged).
what is localisation of function?
the theory that different areas of the brain are responsible for different behaviours, processes or activities.
what are the four lobes of the brain?
frontal lobe, parietal lobe, occipital lobe and temporal lobe.
what areas are located in the frontal lobe?
motor area and broca’s area
what is the function of the motor area and what will happen if it gets damaged?
it is in the back of the frontal lobe and controls voluntary movement in the opposite side of the body (left controls right, right controls left), damage to this area of the brain may result in a loss of control over fine movement.
what is the function of broca’s area and what will happen if it gets damaged?
it is in the left hemisphere of the frontal lobe and it is responsible for speech production, damage to this area causes broca’s aphasia - characterised by speech that is slow, laborious and lacking influency.
what area is located in the parietal lobe?
somatosensory area
what is the function of the somatosensory area and what will happen if it gets damaged?
it is at the front of the parietal lobe and it is where sensory information from the skin (heat, pressure and so on) is processed, damage to this area can affect the sensitivity of certain parts of the body.
what area is located in the occipital lobe?
visual area
what is the function of the visual area and what will happen if it gets damaged?
each eye sends information from the right visual field to the left visual cortex and from the left visual field to the right visual cortex, damage to the left hemisphere can produce blindness in part of the right visual field of both eyes and vice versa.
what areas are located in the temporal lobe?
wernicke’s area and the auditory area
what is the function of the auditory area and what will happen if it gets damaged?
it analyses speech based information and damage to this area may produce partial hearing loss - the more extensive the damage, the more extensive the loss.
what is the function of wernicke’s area and what will happen if it gets damaged?
it is in the left temporal lobe and it is responsible for language comprehension, damage to this area leads to wernicke’s aphasia and people who have this will often produce nonsense words (neologisms) as part of the content of their speech.
what are the strengths of the localisation of the brain theory?
there is research evidence: neurosurgery - damage to areas of the brain has been linked to mental disorders and neurosurgery is a last resort method, dougherty et al (2002) found that a third of OCD sufferers who had part of the cingulate gyrus removed from their brain showed improvement in symptoms following the procedure, which suggests that behaviours associated with serious mental disorders may be localised.
there is research support:
- petersen et al (1988) found that Wernicke’s area was active when performing listening tasks, and Broca’s area was active when undertaking reading tasks which supports the idea that different areas of the brain have specific functions.
- buckner and peterson (1996) revealed semantic and episodic memories reside in different parts of the prefrontal cortex.
what is a weakness of the localisation of the brain theory?
dick and tremblay (2016) found that only 2% of modern researchers think that language in brain is completely controlled by broca’s and wernicke’s area, advances in the brain imaging techniques mean that neural processes in the brain can be studied with more clarity so it seems that language function is distributed more holistically which contradicts localisation theory.
what is brain plasticity?
the brain’s capacity to reorganise its structure and function throughout life, due to experience (environmental).
what is functional plasticity?
the brain’s ability to move functions from a damaged area of the brain to other undamaged areas.