Central Nervous System
A major division of the nervous system comprising the brain and spinal cord, which receives neural messages from and transmits neural messages to the peripheral nervous system
Brain
A complex organ contained within the skull that coordinates mental processes and behaviour, and regulates bodily activity
Spinal cord
A cable of nerve tissue that extends from the brain, connecting it to the peripheral nervous system
Peripheral Nervous System
A major division of the nervous system comprising every neuron in the body outside the central nervous system
Somatic Nervous System
A division of the peripheral nervous system that transmits neural messages related to voluntary motor movement
Skeletal muscles
Muscles connected to the skeleton that carry out voluntary motor movements
Autonomic Nervous System
A division of the peripheral nervous system that regulates visceral muscles, organs, and glands, and transmits neural messages to the central nervous system about their activity
Visceral muscles, organs, and glands
Muscles, organs, and glands not connected to the skeleton that are predominantly self-regulating and do not require conscious control
Sympathetic Nervous System
A division of the autonomic nervous system that activates visceral muscles, organs, and glands, preparing the body to respond to a threat or stressor
Parasympathetic Nervous System
A division of the autonomic nervous system that maintains the optimal and balanced functioning of visceral muscles, organs, and glands
Neuron
A nerve cell that receives and transmits neural information
Motor (efferent) neurons
Neurons that transmit neural messages about motor movement from the central nervous system to the peripheral nervous system
Sensory (afferent) neurons
Neurons that transmit neural messages about bodily sensations from the peripheral nervous system to the central nervous system
Interneurons
Neurons that transfer neural messages between sensory neurons and motor neurons
Conscious response
A deliberate and voluntary action that is initiated by the brain and performed intentionally by the body
Sensory receptor
A nerve ending that detects internal sensations in the body and external sensations from the environment
Unconscious response
An automatic and involuntary action that is performed by the body independently of the brain
Spinal reflex
An unconscious response to sensory stimuli that is initiated by interneurons in the spinal cord independently of the brain
Reflex arc
The path along which the neural signal is transmitted as part of the spinal reflex
Neural synapse
The region that includes the axon terminals of the presynaptic neuron, the synaptic gap, and the dendrites of the postsynaptic neuron
Presynaptic neuron
The neuron that releases neurochemicals into the neural synapse
Axon terminal
The end of a neuron that releases neurochemicals into the neural synapse
Synaptic gap
The space between the presynaptic neuron and the postsynaptic neuron
Postsynaptic neuron
The neuron that receives neurochemicals from the neural synapse
Dendrite
A branched extension of a neuron on which receptor sites are located
Receptor site
A protein molecule on the dendrites of a neuron that receives neurochemicals
Neurochemical
A chemical substance that transmits neural information within the nervous system
Synaptic transmission
The chemical conveyance of neural information between two neurons across a neural synapse
Neurotransmitter
A chemical molecule that has an effect on one or two postsynaptic neurons
Action potential
An electrical impulse that travels down the axon of a neuron
Excitatory effect
When the neurotransmitter increases the likelihood of the postsynaptic neuron firing an action potential
Glutamate
The main excitatory neurotransmitter in the nervous system
Inhibitory effect
When the neurotransmitter decreases the likelihood of the postsynaptic neuron firing an action potential
GABA
The main inhibitory neurotransmitter in the nervous system
Neuromodulator
A chemical molecule that has an effect on multiple postsynaptic neurons
Dopamine
A neuromodulator primarily responsible for voluntary motor movement, the experience of pleasure, and reward-based learning
Serotonin
a neuromodulator primarily responsible for the regulation of mood and sleep
Synaptic plasticity
The ability of synaptic connections to change over time in response to activity or experience
Sprouting
The ability of dendrites or axons to develop new extensions or branches
Rerouting
The ability of a neuron that is connected to a damaged neuron to create an alternative synaptic connection with an undamaged neuron
Pruning
The elimination of synaptic connections that are not adequately activated
Learning
The process of acquiring knowledge, skills, or behaviours through experience
Memory
The process of encoding, storing, and retrieving information that has been previously encountered
Long-term potentiation
The long-lasting and experience-dependent strengthening of synaptic connections that are regularly coactivated
Long-term depression
The long-lasting and experience-dependent weakening of synaptic connections between neurons that are not regularly coactivated
Stress
A psychological and physiological experience that occurs when an individual encounters something of significance that demands their attention and/or efforts to cope
Stressor
A stimulus (internal or external) that prompts the stress response
Internal stressor
A stimulus from within a person’s body that prompts the stress response
External stressor
A stimulus from outside of a person’s body that prompts the stress response
Distress
A form of stress characterised by a negative psychological state
Eustress
A form of stress characterised by a positive psychological state
Acute stress
A form of stress characterised by intense psychological and physiological symptoms that are brief in duration
Fight-flight-freeze response
An involuntary and automatic response to a threat that takes the form of either escaping it, confronting it, or freezing in the face of it
Chronic stress
A form of stress that endures for several months or longer
Cortisol
A hormone that is released in times of stress to aid the body in initiating and maintaining heightened arousal
General Adaption Syndrome
A biological model involving three stages of physiological reactions that a person experiences in response to a persistent stressor
Alarm reaction
The first stage of the General Adaptation Syndrome involving the initial decrease and subsequent increase in bodily arousal in response to an immediate stressor
Shock
The first substage of the alarm reaction stage involving decreased bodily arousal for a brief period of time following the initial exposure to a stressor
Countershock
The second substage of the alarm reaction stage in which sympathetic nervous system responses occur that mobilise the body to respond to the stressor
Resistance
The second stage of the General Adaptation Syndrome involving maintaining high levels of bodily arousal in response to a persistent stressor
Exhaustion
The third stage of the General Adaptation Syndrome involving the depletion of energy levels and bodily resources, resulting in an inability to cope with the stressor
Subjective
Something which is based on or influenced by personal feelings or preferences
Appraisal
An assessment or evaluation of stimuli
Primary appraisal
The initial process of evaluating the nature of an incoming stressor, specifically the kind of stress it might cause
Benign-positive
An initial appraisal of a stimulus as neutral or good that does not cause stress for the individual
Irrelevant
An initial appraisal of a stimulus as a non-issue for the individual
Stressful
An initial appraisal of a stimulus as a source of worry or emotional significance for the individual
Harm/loss
A further appraisal of a stressor as having caused some damage to the individual
Threat
A further appraisal of a stressor as potentially causing damage to the individual in the future
Challenge
A further appraisal of a stressor as potentially providing a positive opportunity for growth or change for the individual
Secondary appraisal
The process of evaluating the resources required and available in order to cope with a stressor
Coping
The process of dealing with a stressor
Emotion-focused coping
The use of coping strategies that target the emotional components of a stressor, dealing with it indirectly rather than confronting its source
Problem-focused coping
The use of coping strategies that directly target the source of the stressor, aiming to reduce it in a practical way
Gut
The long flexible tube from mouth to anus that is the passageway involved in digestion
Gut microbiota
All of the microorganisms that live in the gut
Gut microbiome
All of the genes of the microorganisms that live in the gut
Gut-brain axis
The bidirectional connection between the gut and the brain through the enteric and central nervous systems
Enteric nervous system
The network of nerves in the gut and is a subdivision of the autonomic nervous system
Vagus nerve
The longest cranial nerve that connects the gut and the brain, enabling them to communicate
Coping
The process of dealing with stress
Mental wellbeing
An individual’s current state of mind, including their ability to think, process information, and regulate emotions
Context-specific effectiveness
When the coping strategy or mechanism used is appropriate for the unique demands of the stressor
Coping flexibility
An individual’s ability to adjust or change their coping strategies depending on the unique and changing demands of a stressor
Approach strategies
Coping strategies that directly confront the source of the stress
Avoidance strategies
Coping strategies that evade the stressor, seeking to indirectly reduce stress