Psychology VCE unit 3 AOS1 (nervous system and stress)

Nervous system

complex, highly organised network of specialised cells that enables the brain to receive information about what is going on from both inside and outside the body and to respond appropriately

Myelin sheath

a layer of fatty tissue covering and *insulating* the axon; speeds up neural transmission

Axon terminal

located at the end of the axon, it transmits messages to the next neuron by secreting neurotransmitters

Neuron

A nerve cell; the basic building block of the nervous system

Axon

A long fibre that carries impulses away from the cell body of a neuron

Dendrite

Tree-like branches of a neuron that are specialised to receive information (neurotransmitters) from neighbouring neurons

Central Nervous System (CNS)

comprises the brain and spinal cord, controls the body by processing and responding to stimuli

Peripheral Nervous System (PNS)

entire network of nerves located outside the central nervous system; carries information to and from the central nervous system

Sympathetic nervous system

a subdivision of the autonomic nervous system; activates internal muscles, organs and glands to prepare for vigorous activity or to deal with a stressor, fear stimulus, threat or emergency

Somatic Nervous System

a sub-division of the peripheral nervous system that carries sensory information to the central nervous system and motor information from it

Autonomic Nervous System

a subdivision of the peripheral nervous system that connects the central nervous system to the body's internal organs and glands, providing feedback to the brain about their activities

Fight/flight/freeze response

emergency response that prepares our body for action; activated by the sympathetic nervous system

Parasympathetic nervous system

a sub-division of the autonomic nervous system that calms or restores the body to its normal state of functioning after the need for sympathetic nervous system activation has passed

Neurotransmitters

a chemical substance produced by a neuron that carries a message to other neurons or cells in muscles, glands or other tissue

Glutamate

the main excitatory neurotransmitter in the CNS, thereby enhancing information transmission by making postsynaptic neurons more likely to fire

GABA

the main inhibitory neurotransmitter in the central nervous system, making postsynaptic neurons less likely to fire

Dopamine

a neurotransmitter or neuromodulator with multiple functions depending on where it acts; functions include roles in coordinating movement, learning and behaviours that are rewarding

Spinal reflex

an unconscious, involuntary response to certain stimuli, initiated within the spinal cord and controlled solely by neural circuits; also called reflex arc

Spinal cord

a long, thin bundle of nerve tissue connecting the brain and rest of the body via the peripheral nervous system; initiates simple reflex responses independently of the brain

Sensory neurons

nerve cells that are activated by sensory input from the environment

Motor neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands (efferent neurons)

Interneurons

a neuron which transmits impulses between other neurons, especially as part of a reflex arc

Dopamine

a neurotransmitter or neuromodulator with multiple functions depending on where it acts; functions include roles in coordinating movement, learning and behaviours that are rewarding

Conscious response

a reaction to a sensory stimulus that involves awareness; usually voluntary, goal-directed and with some degree of control over it

Brain

an intricate network of cells that plays a vital role in processing information received through nerve pathways from the body and in directing actions within the body

Enteric nervous system

a sub-division of the autonomic nervous system embedded within the walls of the gastrointestinal (digestive) tract and dedicated to its functioning

Long-term depression

the long-lasting weakening of synaptic connections due to repeated low intensity stimulation

Long-term potentiation

the long-lasting strengthening of synaptic connections due to repeated high intensity stimulation

Neuromodulator

a neurotransmitter that can influence the effects of other neurotransmitters; also called modulator neurotransmitter

Pruning

the elimination of weak, ineffective or unused synapses (and therefore connections to other neurons) to increase the efficiency of neural transmission

Rerouting

the formation of new connections between connections to establish alternative neural pathways

Sensory receptor

a nerve ending that sends signals to the central nervous system when it is stimulated

Serotonin

a neurotransmitter or neuromodulator with multiple functions depending on where it acts; functions include emotional processing, mood, and sleep onset

Sprouting

the creation of new extensions on a neuron to allow it to make new connections with other neurons

Synaptic plasticity

the ability of a synapse to change in response to experience

Unconscious response

a reaction to a sensory stimulus that does not involve awareness; involuntary, unintentional, automatic and we cannot ordinarily control its occurrence

Neural pathway

a route based on interconnected neurons that form a communication network within the brain and between the brain and other parts of the nervous system and body

Excitatory effect

the increased likelihood that the post-synaptic neuron will fire a neural impulse

Inhibitory effect

the decreased likelihood that post-synaptic neuron will fire a neural impulse

Synaptogenesis

the formation of new synapses that result from the process of sprouting

Stress

a *psychological* and *physiological* response to internal or external sources of tensions that challenge a person's ability to cope, these can be real or perceived

Fight-flight-freeze response

a physiological response to stress that causes an organism to react in a combative manner (fight), by removing themselves from the situation (flight), or by not reacting at all (freeze)

General Adaptation Syndrome (GAS)

a model developed by Selye to explain the biological processes involved in chronic stress; 1. alarm, 2. resistance and 3. exhaustion

Alarm

the 1st stage of Selye's GAS model where the fight-flight-free response is activated to prepare the person to deal with the challenge or stressor

Alarm reaction

this stage has two components; shock & countershock

Resistance

the 2nd stage of Selye's GAS model when the body's resistance to the particular stressor develops and rises above its normal levels in order to cope with and adapt to the stressor

Exhaustion

the 3rd stage of Selye's GAS model where the body cannot continue to cope with the stressor and its resistance begins to drop; the body's resources are depleted and very tired which can lead to life-threatening illness and death if the stress continues

Adrenaline

a neurohormone secreted by the adrenal glands, especially in conditions of stress, increasing rates of blood circulation, breathing, and carbohydrate metabolism and preparing muscles for exertion

Stressor

A situation, event, or person that causes the stress response

Lazarus and Folkman's Transactional Model of Stress and Coping

a cognitive model focused on the transaction between an individual's perception of a stressor and the stressor itself.

Threat

an assessment that there may be a future harm or a loss

Secondary appraisal

the appraisal where a person considers whether they have sufficient coping resources available to them and how they will respond to the event (stressor)

Cortisol

hormone released by the adrenal gland in response to stress; metabolises blood sugars and reduces inflammation

Avoidance strategies

tend to be emotion focused as the fundamental goal is to avoid feelings of distress and emotional upset eg. denial, procrastination, oversleeping

Approach strategies

an effort to cope with stress by *confronting* the stressor and dealing with it and/or its effects eg. seeing a psychologist

Acute stress

stress that lasts for a relatively short time

Chronic stress

stress that continues for a prolonged period of time

External stressor

a stressor which originates outside the individual from situations and events in the environment

Gut-brain axis (GBA)

a bidirectional, multi-faceted communication link between the central and enteric nervous systems

gut microbiota

the microorganisms (e.g. bacteria, viruses and fungi) present in each individual's digestive tract ('gut')

Internal stressor

a stressor that originates within the individual

Primary appraisal

evaluating the significance of a situation (resulting in a decision that it is either irrelevant, benign-positive or stressful, and if stressful, harm, threat or challenge)

Countershock

in the General Adaptation Syndrome, rebound from the temporary state of shock during the initial alarm reaction stage

Shock

in the General Adaptation Syndrome, the temporary state immediately following exposure to a stressor during the initial alarm reaction stage

Coping flexibility

the ability to effectively modify or adjust one's coping strategies according to the demands of different stressors

Context-specific effectiveness

in relation to coping, when there is a match or 'good fit' between the coping strategy that is used and the stressful situation

Coping

in relation to stress management, attempting to manage the demands of a stressor in some effective way