Aos 3.1 - Nervous system and stress Flashcards
Acculturative stress
the stress people experience when trying to adapt to the values, customs and language preferences of a new culture when living in it for a considerable period of time.
Action potential (neural impulse)
the electrical charge that travels down the axon of a neuron during transmission of a neural impulse
occurs as the result of the rapid depolarisation of the neuron’s membrane, prompting the release of neurotransmitters
Acute stress
stress episodes that tend to produce a very high arousal level for a relatively short time
Adrenal glands
endocrine glands that sit at the top of the kidneys and are responsible for releasing hormones in response to stress through the synthesis of adrenaline (epinephrine), noradrenaline and cortisol
Adrenaline (epinephrine)
The hormone produced by the adrenal glands that also acts as a neurotransmitter
generally arousing the body through a sympathetic response to prepare it for action
Afferent information
sensory information coming into the CNs (incoming info)
Afferent nerves (sensory nerves)
specialised neurons within the pns that detect sensory info received from receptors all over the body and transmit this to the brain via the spinal cord
Agonist
in neural communication, a substance that binds to a neuroreceptor to produce a similar effect of a neurotransmitter in either exciting or inhibiting a postsynaptic neuron
Alarm reaction
the initial stage of the General Adaptation Syndrome
occurs when the person first becomes aware of the stressor, triggering a general defensive reaction to the stressor resulting in a state of tension and alertness, and a readiness to respond to the stessor
Antagonist
in neural communication, a substance that suppresses the release of a neurotransmitter or blocks the receptor sites, making the postsynaptic neuron less likely to fire
Appraisal
the cognitive interpretation and evaluation of a situation which then affects our emotional, or affective, response
Appraisal-focused coping
the process of dealing with ongoing stress by reassessing the situation to modify our perception and interpretation of the stressor in order to alter our response
Approach strategies
efforts to confront a stressor and deal directly with it and its effects.
activity is focused towards the stressor, its causes and a solution that with address the underlying problem, issue or concern and minimise or eliminate its impact
strategies involve engagement with the stressor
Arousal
activation of bodily resources leading to a heightened state of physical aleertness and readiness for action
Autonomic nervous system (ANS)
The branch of the PNS that’s divided into the sympathetic and parasympathetic nervous systems
connect the CNS to the body’s visceral muscles, internal organs and glands regulates and provides feedback to the brain about their activities
both systems work to expend and conserve energy
The ANS is ‘autonomous’ because many of the organ, glands and processes under its control are self-regulated
Avoidance strategies
efforts that evade a stressor and deal indirectly with it and its effects.
activity is focused away from the stressor and there is no attempt to actively confront the stressor and its causes.
Strategies involve behavioural or emotional disengagement
Axon
a single, tube-like extension of a neuron that transmits neural information away from the cell body to the synaptic connection with other neurons
Axon collaterals
small branches at the end of an axon
Axon terminals
the small knob-like swelling at the end of the axon collaterals.
Neurotransmitters are released from the tip of axon terminals to send messages to the dendrites of other neurones
Basal ganglia
a region of the brain beneath the cortex that plays a role in controlling movement and motor coordination
Brain
The command centre of the CNS responsible for coordination of all of the body’s conscious and unconscious activities
Central nervous system (CNS)
comprised of the brain and the spinal cord
main function is to process infor received from the body’s internal and external environments
activates appropriate responses
transmits neural messages to the peripheral nervous system
Cerebellum
structure at the rear base of the brain responsible for:
- controlling muscle tone
- balance
- coordination of fine motor skills
involved in the formation and storage of procedural memories and implicit memories of simple conditioned reflexes
Cerebral cortex
thin layer of tissue that constitutes the wrinkled outer layer of the cerebrum.
enables conscious experience and higher mental functioning, and basic sensory processing and motor functioning
Cerebrum
the largest structure in the human brain, responsible for controlling our higher cognitive and emotional functions
Challenge
an assessment of a situation as being an opportunity with the potential for personal gain or growth
Chronic stress
Ongoing demands, pressures and worries that produce and increased arousal level that persists over a relatively long time a
likely to be harmful in some way to health and wellbeing, both psychological and physically
Conscious response
a reaction to a sensory stimulus that involves attention and awareness
will usually be a voluntary, intentional, controlled reaction that is also likely to be goal directed
Context-specific effectiveness
when there is a match or a ‘good fit’ between the coping strategy that is used and the stressful situation
Coping
a specific method to effectively manage, tolerate, or reduce the demands and reactions to a stressor through cognitive and behavioural efforts
to deal with specific internal and/or external stressors that are taxing or exceeding the resources of the person
Coping flexibility
the ability to effectively modify or adjust one’s coping strategies according to the demands of different stressful situations
Cortisol
hormone produced by the adrenal glands in response to prolonged stress
main effect is to energise the body by increasing energy supplies
helps to repair damage to the body while under stress through an anti-inflammatory effect
also stops tissue repair & impairs immune system functioning
Countershock
the 2nd component of the General adaptation syndrome’s alarm reaction stage
involves the defensive rebound from the shock produced by a stressor
increases body’s resistance to the stressor by activating sympns
Dendrites
an extension of a neuron that detects and receives information from other neurons via neurotransmitters
Dopamine
neurotransmitter that is necessary for production of smooth, coordinated function of the body’s muscles and movement
associated with the reward-seeking system of the brain, providing feelings of pleasure and reinforcement to motivate a person to perform certain activities
Efferent information
motor info leaving the CNS (outgoing)
Efferent nerves (motor nerves)
neurons in the PNS that transmit information or motor commands from the brain to the muscle, glands or organ to enable a response
Emotion-focussed coping
the process of dealing with ongoing stress by attempting to reduce the negative feelings in a stress response in order to deal with the emotional response to a stressor
tend to be used when we believe that we have little or no control over a situation and therefore cannot do anything to change the circumstance
Eustress
term used to refer to “good’ stress involving a beneficial or desirable psychological response to a stressor (feeling enthusiastic, excited, motivated)
typically short-term & can provide energy & motivation to achieve a goal
Excitatory neurotransmitters
neurotransmitters that stimulate or activate postsynaptic neurons to perform their functions
Excitatory synapse
at this synapse, the electrochemical process depolarises the post-synaptic membrane, thus making its interior charge more positive
this process initiates the firing of an action potential by a target cell
Exhaustion
the 3rd stage of the General Adaptation Syndrome - if stress is prolonged or there are several stressors, the body’s ability to resist decreases, falling below normal levels, resulting in depleted energy, weakness, and vulnerability to physical and psychological illnesses
‘Fight-flight-freeze’ response
triggered by the hypothalamus
an involuntary state of increased arousal that occurs when the sns is activated
all 3 responses considered to be adaptive survival mechanisms that enable us to effectively react to a threat
Freeze reaction
when initiated, parasympathetic ns dominate over existing effects over sns leaving the orgnaism unable to move
resulting condition allows animal to quickly escape by suddenly switching to sns
Gamma-Amino Butyric Acid (GABA)
the primary inhibitory neurotransmitter in the cns
works throughout the brain to slow down neural activity, making postsynaptic neurons less likely to fire in order to fine-tune neurotransmission
inhibits over-excitation in the brain to maintain neurotransmission at an optimal, or best possible level
General Adaptation Syndrome (GAS)
a three-stage physiological response to stress that occurs regardless of the stressor that is encountered
consists of 3 stages:
1. an alarm reaction state (shock & counter shock)
2. resistance stage
3. exhaustion stage
Glial cells (Glia)
specialised non-excitable cells that
- perform supportive roles to neurons in the brain by
- hold neurons together
- facilitatee neural transmission by forming the myelin sheath,
- remove damaged and dead neurons
- prevent poisonous substances in the blood from reaching the brain
Glutamate (Glu)
the primary excitatory neurotransmitter in the CNS
enhances information transmission by making postsynaptic neurons more likely to fire
2nd most abundant ntm in the brain & involved in most aspects of normal brain function (perception, learning, memory, thinking, movement)
Gut microbiota (gut flora)
the system of micro-organisms, including bacteria, that live in the digestive system
play important roles in digestion and metabolism
also affect brain health and functioning through extensive connections between the ens and cns
Gut-brain axis (GBA)
network of 2-way communication that allows communication between gut microbiota and brain
included communication via chemical transmission through bloodstream, neural and hormonal pathways, and via immune system
causes disorders in the gut to affect the brain and vice versa
Homeostasis
a state of internal equilibrium which an individual actively seeks to maintain
Hormones
Chemical messengers within the body, manufactured and secreted by the endocrine glands, that regulate metabolism and influence body growth, mood, and sexual characteristics
HPA axis
The hypothalamic-pituitary-adrenal (HPA) axis
a major physiological pathway of the neuroendocrine system
regulates many body processes in a chain of direct influences and feedback interactions, in particular mediating the body’s response to chronic, ongoing stress
Hypothalamus
structure in the brain that triggers the ‘fight-flight-freeze’ response through its link with the pituitary gland, leading to a state of increased arousal in reaction to a perceived threat
Inhibitory neurotransmitters
neurotransmitters that block or prevent postsynaptic neurons from firing
Inhibitory synapse
at this synapse, the electrochemical process hyperpolarises the post-synaptic membrane, thus making its interior charge more negative
stops the firing of an action potential by a target cell.
Interneuron
aka: connecting or association neuron
neuron that sends messages between sensory & motor neurons within the cns, relaying info from one to the other
‘Lock and key’ process
receptor sites of the postsynaptic neurons’ dendrites recognise neurotransmitters by their chemically-distinct shape
when the shape matches the receptor site, it binds to the receptors in order to allow neurotransmission of the message
if a neurotransmitters’ shape doesn’t fit it is blocked
Locus of control
a general expectation about whether the results of your actions are under you own control (internal locus) or beyond your control (external locus)
Long-term depression (LTD)
a form of neural plasticity that results in a long-lasting reduction in the strength of a neural response due to persistent weak stimulation
Long-term potentiation (LTP)
a form of neural plasticity
results in long-lasting strengthening of neural connections at the synapse due to repeated stimulations between neurons during learning.
improves ability of 2 neurons to communicate
^ resulting in enhanced functioning of the neurons when activated.
Demonstrated to occur in cells of the hippocampus - produce the neural changes that underlie the formation of memory
Motor (efferent) information
information carried along motor neural pathways by motor neurons to skeletal muscles to control their activity by causing them to contract or relax
motor neuron
aka: efferent, effector or motor neuron
neurons within the pns that transmit information or commands from the brain via the spinal cord to cells in skeletal muscles, organs & glands to enable a response
Myelin sheath
the white, fatty coating (made of glial cells) that surrounds and insulates the axon to allow the rapid movement of messages along the axon without being interrupted or distorted by interferences
Neuromodulator
a chemical that acts like a neurotransmitter, but doesn’t act alone
influence the action of another neurotransmitter and are not restricted to the synaptic cleft
Neuron
a nerve cell
receives and transmits
neural information to other cells via electrochemical impulses
Neurotransmitter
a chemical substance manufactured by the neuron, released from the terminal button of a pre-synaptic neuron in response to a neural impulse to pass across the synaptic gap and carry its message by attaching itself to receptor sites
Non-skeletal muscles
aka: visceral muscles
muscles that are associated with internal organs, such as the heart and lungs, as well as the glands
Noradrenaline
a neurotransmitter secreted from neurons and a hormone secreted by the adrenal glands into the blood
Parasympathetic nervous system
subdivision of the ans:
- counterbalances activities of the sns by decreasing activity of most visceral muscles, organs & glands
- restores & maintaines normal functioning in times of minimal stress & absence of threat
- involved in routine, everyday activities and dominates the ans most of the time
Parkinson’s disease
a neurodegenerative disorder of the cns characterised by both motor and non-motor symptoms
motor symptoms result from the degeneration and loss of neurons in the sustantia nigra
Peripheral nervous system (pns)
the entire network of nerves outside the cns
divided into sns and ans
main function to transmit info to and from the cns
Pituitary gland
the ‘master gland’ controlling the release of hormones from the other glands within the endocrine system
Primary appraisal
an evaluation or ‘judgement’ about the signicance of an event to decide whether the event is irrelevant, benign, +ve, or stressful
if it is stressful then we engage in more appraisals to decide if harmful, threatening, or challenging
Problem-focused coping
deal directly with the stressor to manage, reduce or eliminate it
tend to be used when we believe that we have some control over a stressful situation and think that we can change the circumstances, or at least change ourselves to more capably deal with the circumstances
Psychobiological process
processes that incorporate both biological and psychological components and consequences
psychosomatic illness
actual physical symptoms and/or ailments which are attributed to a combination of physiological and psychological factors, such as emotional distress
Receptor site
minute areas on the surface of the post-synaptic neuron that are specialised to receive specific neurotransmitter molecules
Reflex arc
aka: spinal reflex
response to an incoming stimulus that is automatically ‘reflected back’ from the spinal cord enabling the motor neurons to react to a sensory stimulus without any initial input from the brain and before the brain processes a conscious perception of the stimulus
Rerouting
in cases where damage has occurred within the brain, undamaged neurons may sprout new extensions to compensate for any loss of function
if an undamaged neuron has lost a communication point with an active neuron, it may seek a new neuron to link with
allows messages to be sent along a new neural pathway & around the damaged area
Resistance
during the 2nd stage of general adaptation syndrome body’s resistance to the stressor rises above normal. the intense arousal of alarm reaction diminishes but then remains at a normal level. Since the body needs to generate resistance, all unnecessary physiological processes shut down
Reuptake
the process whereby neurotransmitter molecules that do not bind to receptors in the postsynaptic neuron are absorbed back into the terminal buttons by the presynaptic neuron
Secondary appraisal
an assessment of the controllability of the situation and the individual’s coping resources and options for dealing with the event
Sensory (afferent) information
info received at sensory receptor sites in the body and carried along afferent neural pathways by sensory neurons
Sensory neurons
aka: afferent neurons or affectors
neurons in the pns that detect sensory info from both the external and internal environments
received from receptors all over the body and transmit this to the brain via the spinal cord
Serotonin
a modulatory neurotransmitter that regulates many functions, including:
mood, the sleep-wake cycle, memory processing, and appetite
Shock
the 1st component of the general adaptation syndrome’s alarm reaction stage where the body’s ability to deal with the stressor temporarily falls below its normal level
physiologically, the body reacts as if it were injured
somatic nervous system
a network of nerves responsible for carrying sensory info to the cns and motor info away from the cns
to initiate voluntary motor movement
Spinal cord
long, thin bundle of nerve tissue that extends from the base of the brain to lower back
functions:
- receive sensory info from body & send to brain
- receive motor info from brain & send to body
- initiate relexes
Sprouting
following stimulation and repeated activation, the growth of more neural branches to make more connections with other neurons
Stressor
a specific physical or psychological event or situation that is assessed by an individual as being a challenge or potential threat to their well-being which leads them to experience stress
Sympathetic nervous system
subdivision of the ans responsible for activating internal muscles, organs and glands
prepares body for vigorous activity or to deal with a stressful/threatening situation
enhances survival by providing an immediate response
Synaptic plasticity
the ability of neurons to change their structure to create new synapses or eliminate redundant ones
Synaptic pruning
the elimination of redundant synaptic connections, particularly during the brain’s early development
Synaptic vesicles
structures within the axon terminals that house and release neurotransmitter molecules
Synaptogenesis
the formation of new synapses as a result of learning, particularly during the brain’s early development
Terminal button
a small structure like a sac that stores and secretes neurotransmitters that are manufactured by the neuron and carries its chemical message to other neurons or cells
Tonic immobility
the aspect of the fight-flight-freeze response involving the apparent frozen state of the body
eg. playing dead
Transactional model of stress and coping
theory which proposes that stress involves an encounter between an individual and their external environment, and that a stress response depends upon the individual’s interpretation of the stressor and their ability to cope with it
Vagus nerve
the 10th cardinal nerve that is the major communication route in the gut-brain axis
extends from brainstem to provide parasympathetic innervation to many organs, including the gut and digestive organs
Viscera muscles
muscles involved in the activity of internal organs and glands that do not depend on voluntary control by the brain as they have built-in mechanisms for generating activity to function continuously
Enteric nervous system
the network of nerves in the gut and is a subdivision of the autonomic nervous system
