2026: Psych - Unit 3 AOS 1

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 and spinal cord

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 and Autonomic nervous system

Somatic - A division of the peripheral nervous system that transmits neural messages related to voluntary motor movement.

Autonomic - 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 and Parasympathetic nervous system

Sympathetic - 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 - 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 neurons (also known as efferent neurons) and Sensory neurons (also known as afferent neurons)

Efferent - Neurons that transmit neural messages about motor movement from the central nervous system to the peripheral nervous system.

Afferent - Neurons that transmit neural messages about bodily sensations from the peripheral nervous system to the central nervous system.

Interneurons neurons

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 without conscious awareness in response to internal and external sensory stimuli.

Spinal reflex

An unconscious response to sensory stimuli that is initiated by interneurons in the spinal cord independently of the brain.

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 (Also known as terminal button)

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. it enables rapid communication between two neurons across a neural synapse.

Action potential

An electrical impulse that travels down the axon of a neuron.

Excitatory effect and Glutamate

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 and GABA (gamma-aminobutyric acid)

Inhibitory effect - When the neurotransmitter decreases the likelihood of the postsynaptic neuron firing an action potential.

GABA (gamma-aminobutyric acid) - The main inhibitory neurotransmitter in the nervous system.

Neuromodulator

A chemical molecule that has an effect on multiple postsynaptic neurons. Modulates neural activity on a larger scale than neurotransmitters, as they are released into multiple neural synapses and consequently affect 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.

Neural plasticity

The ability of the brain’s neural structure and functioning to be changed through experience throughout a lifespan.

Synaptic plasticity

The ability of synaptic connections to change over time in response to activity or experience.

Sprouting and rerouting and Pruning

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 and memory

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 and Long-term depression

Potentiation - The long-lasting and experience-dependent strengthening of synaptic connections that are regularly coactivated.

Depression - The long-lasting and experience-dependent weakening of synaptic connections between neurons that are not regularly coactivated.

Stress and Stressor

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 - Stressor a stimulus (internal or external) that prompts the stress response.

Internal stressor and External stressor

Internal - A stimulus from within a person’s body that prompts the stress response

External - A stimulus from outside of a person’s body that prompts the stress response.

Distress and Eustress

Distress - A form of stress characterised by a negative psychological state.

Eustress - A form of stress characterised by a positive psychological state.

Acute stress and Chronic stress

Acute - A form of stress characterised by intense psychological and physiological symptoms that are brief in duration

Chronic - A form of stress that endures for several months or longer.

The flight-or-fight-or- 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.

Cortisol

A hormone that is released in times of stress to aid the body in initiating and maintaining heightened arousal.

General Adaption Syndrome (GAS)

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 GAS

Involving the initial decrease and subsequent increase in bodily arousal in response to an immediate stressor.

Shock + Counter shock (1st + 2nd substage of stage 1 of GAS)

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.

Counter shock - 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 GAS

Involving maintaining high levels of bodily arousal in response to a persistent stressor.

Exhaustion - the third stage of the GAS

Involving the depletion of energy levels and bodily resources, resulting in an inability to cope with the stressor.

Appraisal

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, Irrelevant, Stressful - Primary appraisal part 1

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, Threat, Challenge - Primary appraisal part 2 after stressful

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.

Emotion-focused coping, problem-focused coping - Secondary appraisal

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 (also known as the gastrointestinal tract)

Vagus nerve

Gut - The long flexible tube from mouth to anus that is the passageway involved in digestion.

Vagus nerve - The longest cranial nerve that connects the gut and the brain, enabling them to communicate.

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.

Coping and mental wellbeing

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 and Avoidance strategies

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.