2026 psych

Synapse

point of Communication between two neurons, or between a neuron and a target cell, such as a muscle or a gland.

Excitatory

stimulates the postsynaptic neuron, making it more likely to fire action potential or neural impulse

inhibitory

the decreased likelhood that the post-synaptic neuron will fire an action potential or neural impulse

Glutamate

the main excitatory neurotransmitter in the nervous system, involved with learning and memory

• is released when a neural pathway associated with an experience is stimulated or activated.

• cognition, memory formation, learning, behaviour, moement, and sensation

• stimulates neural activity

• canfeine can increase glutamate activity

GABA

main inhibitory neurotransmitter in the nervous system, associated with anxiety, specific phobias and parkinson’s disease

• essential for motor control, vision and decreasing anxiety

• supresses or slows down neural activity

• one of the main neurotransmitters involved with anxiety treatment

  • when GABA is released across the synapse, the brain and body are calmed

• alcohol can INCREASE GABA activity, accounting for its sleep enhancing effects (sedative)

• Too little can be associated with anxiety and epileptic seizures as the brain is ‘over firing’

• couterbalances glutamate

CNS

the brain and the spinal cord; processes and coordinates responsess to sensory stimuli

• sends motor info to the PNS via motor neurons (efferent)

• receives sensory info from the body (PNS) via sensory neurons (afferent)

PNS

all the nerves outside the central nervous system that carry messages between the central nervous system and muscles, organs and glands throughout the body.

somatic NS

a subdivision of the PNS that carries sensory information to the CNS and motor information to the body.

• voluntary movement

• comprised of sensory (afferent) and motor (efferent) neurons

Autonomic NS

a subdivision of the PNS that controls the body’s internal environment in a self-regulated manner.

• regulates involuntary functions of the body: heart rate, digestion & breathing

• divided into sympathetic and parasympathetic

Parasympathetic NS

a subdivision of the Autonomic NS that:

• keeps homeostasis

• counteracts the activity initiated by the SYMPATHETIC NS

• restores body to a state of calm after arousal or under threat (20-30 mins)

• Dominates the SYMPATHETIC NS most the time

Sympathetic NS

Activates internal muscles, organs or glands to prepare body for heightened levels of arousal (under threat).

• Fight or flight reponse

• increased stress/increased alertness

• increases heart/breathing rate, blood pressure etc - to pump more oxygen to body

• decreases use of non-essential functions like digestion

• if in this intense arousal state for too long, one is in danger of developing physiological or psychological disorders

Enteric NS

• largest part of ANS

• responsible for controlling the functions of digestive system

• can communicate directly with CNS

• can function independently of the CNS (‘second brain’)

• sends and receives messages from both para/sympathetic NS

• controls movement of food thru digestive system and mixes digestive enzymes

• controls the actions of gastrointestinal tract without CNS control

• connects with CNS via the VAGUS NERVE (feelings of hunger or fullness)

Afferent transferal

information transferred ascending (toward the CNS)

• sensory neurons

Efferent transferal

information transferred descending (away from the CNS)

• motor neurons

Spinal cord (CNS)

• receives sensory info from PNS and transmits to brain

• carries motor info from brain to PNS

• works with brain

Spinal reflex

steps:

• sensory receptors detect a stimulus

• sensory neurons transmit neural message to spinal cord afferently

• interneurons in the spinal cord relay the message to motor neurons

• motor neurons send an appropiate neural/motor messgae to the muscle, cuaisng contraction

• sensory information is also transmitted to the brain to enable interpretaiton of the simulus after reflex.

unconcious and not initiated by the brain.

interneurons

the ‘middle man’

• a nerve cell in the spinal cord that connects

  motor and sensory neurons by relaying

  information between the two

• exists exclusively in the CNS

Dendrite

• detects and receieves neural information from other neurons

  • neurotransmitters, neuromodulators, neurohormones

• receptor site

Soma

• message is passed from dendrite to the soma

• cell body

• may collect and integrate information from thousads of other neurons

Axon

• after being integrated from soma, transmitted along the axon

• single tube-like extention

  • transmits neural info to other neurons

neural synapse

• neural impulse reaches axon termina; of the presynaptic neuron

• presynaptic neuron (axon terminal)

  • releases neurochemicals (message or action potential)

• causes vesicals to bind with menbrane and release neurotransmitters into synaptic gap

• neurotransmitters bind to receptor sites on the dendirites of the post-synaptic neuron

• neurotransmitter makes the POST-synaptic neuron

  • more or less likely to fire. (excitatory or inhibitory)

Neurotransmitters

• chemicals released by a presynaptic neuron to send signals/messages to the postsynaptic neuron

• role

  • to transmit chemical the message to adjacent neuron

• releases into the synapse to a single postsynaptic neuron

• moderately fast and direct

• eg: glutamate (excitatory) and GABA (inhibitory)

Neuromodulators

• chemicals released by neurons to alter the effectiveness of neural transmission, therefore INDIRECTLY impacting postsynaptic neurons

• role:

  • to alter the neural transmission of neurons by controlling the synthesis (production of neurotransmitters) and the release of neurotransmitters

• released outside the synapse, affecting a group of neurons

• moderately slow and lasts for a long time

• eg: dopamine & seratonin

• special neuromodulators can act as a neurotransmitter, affecting only an individual neuron

Dopamine

• type of neuromodulator

• has both inhibitory & exitatory effects

• involved in:

  • smooth voluntary muscle movement

  • experiencing pleasure

  • attention

  • mood

  • reward-based learning/motivation

Synaptic plasticity

• refers to the structural and functional changes that occur in the connections between neurons in the brain due to EXPERIENCE

  • these changes can result in the strengthening or weakening of the synapses, or the creation of new ones

• changes include: sprouting, rerouting, and pruning

Sprouting (LTP - Long-term potentiation) - structure

• takes place within the ACTUAL neuron

• results in the development of new structures:

  • increased number of dendrite branches

  • extension of an axon

  • increased number of axon terminals (MORE)

    • the increase of axon terminals = increased vesicles → potentially increased neurotransmitters

  • Expanded neural network

Rerouting (LTP/LTD) - structure

• Establishment of a new neural pathway

• a neuron will seek a connection with another neuron, resulting in a new synaptic connection

• can also lead to sprouting

• when neurons are damaged:

  • undamaged neurons, which can no longer connect with damaged ones, will seek a connection with other undamaged neurons

Pruning (LTD) - structure

• Elimination of synaptic connections

• are eliminated if unused, therefore pruned

• occurs in order to make room for new connections, or to make current connections stronger

Long term potentiation

• the long-lasting strengthening of synaptic connections due to repeated co-activation

• increased tendency of a group of neurons to fire after they have been repeatedly stimulated over a period of time

• LTP increases

  • vesicles

  • neurotransmitters

  • dendritic spines

  • receptor sites

LTP steps

• during learning and gaining experience, the axon terminals of the presynaptic neurons release glutamate (neurotransmitter)

• glutamate has an EXCITATORY effect on the receptors, making it more likely to fire.

  • causes long-lasting changes at the synapse

• repeated glutamate secretion stimulates the release of dopamine

• dopamine interacts with the genes of a neuron to generate new proteins (equates to new structural growth)

LTD

• the long-lasting reduction in the strength of a synaptic connection due to the repeated low-intensity stimulation

  • may prune unimportant or unwanted connections

    • leavings only the important connections that have been strengthened by LTP

• LTD plays important part in clearing the brain of old mems to make way for new info to be learnted and new mems to be formed

• LTD decreases:

  • receptor sites

  • dendrites

  • synaptic connections

Serotonin

And inhibitory neurotransmitter, that also acts as a neuro modulator

• More than 90% of serotonin is found in the gastrointestinal tract as a part of the gut brain axis

• Regulates almost all human behavioural processes

  • mood, perception, reward, anger, appetite, memory, attention etc

• High/balanced serotonin activity → calm, focused, happy and stable moods

  • → greater ability to control/regulate emotions

  • → reduced impulsivity, therefore more able to delay need for awards

• Low levels of serotonin

  • More difficult to regulate/control emotions

    • Higher levels of aggression

  • Increased impulsivity → more likely to take risks for a reward

  • Frequent awakenings, which leads to fatigue

  • Linked to depression and/or anxiety

How does dopamine work when one is hungry?

• steps:

  • dopamine levels decrease below baseline in the reward pathway of brain

  • Results in the sensation of hunger

  • → increasing the food seeking or eating behaviour

  • when one eats → dopamine levels increased in the reward pathway above baseline

  • Pleasure is experienced, reinforcing this pattern of brain activity and behaviour

How does dopamine work in addiction?

Steps/cycle:

• Unhealthy behaviour such as gambling or smoking

• → increased dopamine released in the reward pathway → producing feelings of pleasure

• → overtime, less dopamine is produced → diminish his brain’s supply

• → increases our urge to continue playing/engaging to seek out same feelings of pleasure

• Loops back to the start.

Stress definition?

• a state of mental, emotional and physiological tension caused by a stressor

• perception that it exceeds one’s ability to cope.

what is a stressor

an event that causes stress or something that exceeds our ability to cope perceptually

• internal

  • originates inside the individual

  • psychological (feelings/expectations) or biological (pain, illness)

• external

  • originates outside the individual

  • environmental (loud noises or temperatures) or sociocultural (life events, losses)

acute stress

• sudden or short-term

• Usually more intense (sharper)

• CAN be beneficial and help us with challenges

• triggers fight or flight or freeze response

• releases cortisol and adrenaline

Chronic stress

• Ongoing, prolonged, or long-term

• Less intense/severe

• Generally more detrimental to one's health

• cortisol surge

physiological effects of stress? (FFF)

where is cortisol produced and when

• a hormone produced by the adrenal glands

• released in response to ALL stress.

• released into our bloodstream

effect of cortisol in response to stress

good/increases:

• Boosts energy levels and increases blood glucose levels

• Increased alertness

• Increased brain’s use of glucose

• Increases bodies ability to repair tissues

• Maintains our sympathetic nervous system dominance.

bad/decreases:

• Decreases energy from non-essential bodily functions

  • Digestion, growth, reproductive

• Suppresses immune system, making us more susceptible to diseases

• Risks of cancer, anxiety, depression

what is the Gut brain axis? (GBA)

• the bidirectional communication/connection between the brain and the gut.

  • between ENS and CNS

  • 90% of info is afferent, therefore gut → brain

  • 10% is brain → gut

• connects via the Vagus nerve.

what is gut microbiota and what is the significance?

• millions of microorganisms that mainly assist in the digestion of food.

  • produces and regulates neurochemicals

  • supports gut health

  • supports immune function

• therefore, gut health and mental wellbeing/stress are very much correlated.

what factors impact gut health?

external:

• foods like pre/probiotic foods

• supports and allows for symbiosis

internal

• stress

• cortisol levels

• unique type of microbiotas

• causes DYSbiosis

Shock stage

resistance to stress compared to normal:

• drops below normal

responses:

• acute stress response*

• loss of muscular tone

• body temperature/blood pressure lowered

• parasympathetic NS dominant (freeze)

Counter-shock stage

resistance to stress compared to normal:

• initially below, rises above normal

responses (FFF):

• ADRENALINE & cortisol initially increased

• muscle tense

• heart/breathing rate increase

• pupil dilation

• Sympathetic NS dominance

Resistance stage

resistance to stress compared to normal:

• Well above normal, beginning to drop (does not drop below normal tho)

Responses:

• cortisol levels highest

• high energy due to high blood sugar levels

• immune system functioning IMPAIRED (minor conditions/physiological problems)

  • lack of energy

  • headaches

  • flu/colds

Exhaustion stage

resistance to stress compared to normal:

• well below normal

Responses:

• energy store depleted

• stress coping chemical deplete

• wear and tear

  • fatigue, infections, diseases

• if stressor is eliminated, exhaustion stage may not be reached

Strengths and weaknesses of GAS model

Strengths:

• predictable pattern, therefore easily tested

• BIOLOGICAL MODEL

• one of the first bodels suggesting stress can weaken body’s resistance to illnesses

• non-specific, therefore same effect irrespective of stressor

Limitations:

• humans and rats are physiologgically different (humans stress responses tend to be more complex)

• does not account for individual differences in stress responses

  • eg: disorders like hypertension, PTSD, depression etc

• does not account for psyhcological or cognitive processing in response to stress

Primary appraisal

evaluation on whether the event/stressor is relevant or stressful to the individual

• irrelevant/not stressful? → no stress

• positive/benign → no stress

• stressful

  • harm/loss (already happened) → distress

  • threat (upcoming/anticipated) → distress

  • challenge (beneficial, excitement) → eustress

Secondary appraisal

evaluation on whether the individual has coping resources

• adequate → stress is reduced/managed/minimised

• inadequate → amplified/heightened stress

internal resources → determination, coping strategies

external resources → family and friends help

Strengths and weaknesses of Transactional model

strengths:

• focuses on psychological responses of stress

• emphasises personal nature and individuality

• stress is related to environment → individual has an active role in stress response

• accounts for change in the stressor iteself, therefore our response can also change

Limitations:

• difficult to test through experimentation due to individualistic/subjective nature

• ignores/neglects biological factors

• some may go through secondary and primary appraisal at the same tiime

Coping flexibility

personality trait.

• the ability to effictively modify or adjust one’s coping strategies according to the demands of different stressors.

  • recognise if the use of an approach is appropiate for a specific situation

  • recognise when a coping strategy is effective, thus discontinuing if ineffective

  • producde & implement an alternative coping strategy when needed

• usually, rich coping flexibilty → more adaptive outcomes caused by stress responses

  • reduced physiological dysfunction

Context specific effectiveness

The degree to which a coping strategy is successful in alleviating or minimising stress

• Does the coping strategy meet the demands of the stressor?

• Is there a ‘good fit’ between the strategy and the stressful situation?

Approach strategies

An effort to confront a stressor and deal DIRECTLY with it and its effects

• seeking advice from an expert

• talking about it with friends and family

• developing a plan to increase control over a problem

• accepting responsibility/recognise positive aspects of it

Avoidant strategies

An effort to avoid a stressor and not directly deal with it and its effects

• procrastination

• napping or oversleeping

• substance abuse

• denial

• use of distractions eg TV, games, social media

Strengths and weaknesses of approach strategy

Strengths

• generally considered to be more adaptive and effective than avoidance strategies

• one who uses more approach strategies to cope tend to experience less physiological symptoms, and can function more effectively than one who relies more on avoidance strategies

Limitations

• initially, short-term, approach strategies may increase stress levels when they are engaging with stressor and its causes.

• may require lots of energy to focus and deal with stressor, which means they might neglect other aspects of their lives

Strengths and limitations of avoidance strategies

Strengths

• Selectively avoiding, dealing with unchangable aspects of a stressor by ‘switching off’ may be considered an adaptive strategy

• allows one to conserve energy and focus on other changable stressors

• minimises stress for other stressors

Limitations

• tends to be maladaptive

• excessive reliance → negative consequence:

  • increased vulnerability to mental health problems eg. hypertension, depression

• long-term use can contribute to

  • delinquency

  • socially inappropiate behaviours

  • substance use

• only helpful in short term, long term can obstruct individuals from responding to a stressor

Conscious response

• complex

• Goal directed

• Voluntary.