AOS 1 - Nervous System & Stress

explain the neural pathway of a conscious response

1. the sensory stimuli comes into contact with the sensory receptors

2. sensory neural message is transmitted via afferent pathways in the SNS, then up the spinal cord to the brain

3. the brain processes this sensory message via interneurons into a motor message, initiating a conscious motor response

4. the motor neural message is transmitted via efferent pathways down the spinal cord, then through the SNS to the skeletal muscle

5. the skeletal muscle carry out the conscious motor response to the sensory stimuli

what is a spinal reflex

an unconscious response to sensory stimuli that initiated by interneurons in the spinal cord independently from the brain

explain the neural pathway of a spinal reflex

1. a dangerous or harmful sensory stimuli is detected by the sensory receptor, which is transmit this sensory message via sensory neurons through afferent pathways in the SNS to the spinal cord

2. interneurons in the spinal cord immediately relays this sensory neural signal from sensory neurons to a motor mourn as a motor neurone signal, initiating an automatic and unconscious motor response

3. the motor message is transmitted via motor neurons through efferent pathways in the SNS to skeletal muscle, which carry out this unconscious motor response to the dangerous or harmful stimuli

4. the sensory message continues to travel via afferent pathways in the spinal cord to the brain and then the brain independently reregisters the sensation that trigged the spinal reflex and pain is experienced.

explain the process of synaptic transmissions

neurochemicals are produced in and released from axon terminal in presynaptic neuron into synaptic gap where nuerochemicals bind to receptor sites on the dendrites of postsynaptic neurons and affect the postsynaptic neuron

what is the main excitatory neurotransmitter in the NS

Glutamate

what is glutamates function

important in learning and memory as it enables synaptic plasticity

what is the main inhibitory neurotransmitter in the NS

GABA

what is GABAs function

regulates activation of postsynaptic neuron which helps to reduce anxiety and helps prevent seizures

how can nueromodulateors modulate the effects of neurotransmitters

changing neurotransmitters release patterns and changing the responsiveness of receptor sites of neurotransmitter to enhance inhibitory or excitatory effect

what are 2 types of neuromodulators

dopamine and serotonin

what type of effect does dopamine have

can have excitatory or inhibitory effect

what is dopamines function

coordinates voluntary motor movements, experience of pleasure and reward based learning

what type of effect does serotonin have

inhibitory

what is serotonins function

regulation of mood and sleep

what is synaptic plasticity

ability for synaptic connections to change over time in response to activity or experience

what are the 3 mechanisms of synaptic plasticity

sprouting, rerouting and pruning

what is sprouting

the ability for dendrites or anode to develop new branches to increase reach of neuron and enables the formation of new synaptic connections

how does sprouting occur

due to consent activation

what is rerouting

the ability of a neuron that is connected to a damaged neuron to create an alternative synaptic connection with an undamaged neuron

when does rerouting occur

after brain damage or when breaking out of old habits

what is pruning

the elimination of synaptic connections that are not adequately activated

what is long term potential

long lasting straightening go synaptic connections that are regularly coactivated

what is long term depression

long lasting weakening of synaptic connections between neurons that are not regularly coactivated

explain how long term potential, long term depression and mechanisms of synaptic plasticity in changing an old skill into a new old

as new skill is learnt LTP strengthens neural pathways involved with skill though the repeated coactivation of pathways each time it is practiced. This involves sprouting where new synaptic connections form to support new skill. LTD weakens neural pathway that is involved in old skill due to low levels of activation leading to during on connections. LTP and LTD work together to weaken old skill and strengthen new one.

what is stress

a psychological and physiological experience that occurs when an individual encounters something that significant demands their attention and/or efforts to cope

what is a stressor

a stimulus that prompts the stress response

what is the flight, fight, freeze response

an involuntary automatic response to a threat

what does flight, fight and freeze mean in a flight, fight, freeze response

flight - escaping threat

fight - confronting threat

freeze - immobility in presence of threat

what is cortisol

a hormone released during feeling stress to keep body aroused

what is the biological model to stress

GAS model

what are the 3 stages of the GAS model

alarm reaction, resistance and exhaustion

what are the 2 stages of alarm reaction

shock and counter shock

what is the shock stage of the GAS model

when stressor is seen and brief decrease in bodily arousal, body acts as physically injured

what is the counter shock stage of the GAS model

the sympathetic NS is activated and a FFF response occurs

what is the resistance stage of the GAS model

if stressor is not dealt with there is an activation of the parasmypathetic NS and all unnecessary physiological processes shut down

what is the exhaustion stage of the GAS model

bodys resource have depleted and person is more vulnerable to disease and mental disorders

a strength of the GAS model

recognises a predictable pattern of physiological responses

a limitation of the GAS model

only focuses of biological aspects of stress and ignores psychological factors

what is the psychological model to stress

transactional model of stress and coping

describe the sequence of the transnational model of stress and coping

what is the benign-positive stage

stimulus is seen as neutral or good

what is the irrelevant stage

stimulus does not affect individual

what is the stressful stage

stimulus brings on worry

what is the harm stage

stressor causes damage to individual

what is the threat stage

stressor is potentially causing damage to individuals future

what is the challenge stage

stressor has potential in providing a positive opportunity for change

what is a strength of the transactional model of stress and coping

allows one to track the subjective stress response of an individual

what is a limitation of the transactional model of stress and coping

does not include the biological processes of stress

what is the effects on gut when stress is balanced and individual maintains good diet

there is a positive balance of microbes in guts microbiota ad digestion and excretion is regular

what is the effects on brain when there is balanced microbes

encourages positive mindset on diet and lowers secretion of stress hormones

what is the effects on gut when stress NOT is balanced and individual DOESNT maintain good diet

there is a negative balance of microbes in guts microbiota ad digestion and excretion is irregular

what is the effects on brain when there is inbalanced microbes

discourages healthy diet and increases production of stress hormones

what is coping

the process of dealing with stress

what is context-specific effectiveness

when coping strategies which use are appropriate for unique stressor

what is coping flexibility

individuals ability to adjust to change their coping strategies sending on unique stressor

what is an approach strategy

directly confronts source of stressor

what is an avoidance strategy

evading stress well seeking to reduce stress