VCE Psychology Unit 3 AOS 1

Role of the nervous system

To receive information externally/internally, process information and coordinate responses to the information

Central nervous system

Consists of the brain and spinal cord, responsible for processing information and coordinating responses throughout the body.

Peripheral nervous system and role

Nerves outside the central nervous system
Transmits sensory information to the central nervous system and motor information from the brain to the muscles, organs and glands.

Role of the brain

Is responsible for processing sensory information from neural pathways and initiating motor movement.

Role of the spinal cord

Transmitting sensory information received from the PNS to the brain and motor information from the brain to muscles, glands and organs.

Nervous systems in Peripheral NS

somatic nervous system and autonomic nervous system

Somatic nervous system

A component of the peripheral nervous system that:

1. Initiates voluntary muscle movement by relaying motor messages to muscles

2. Enables sensation by relaying sensory info from sensory receptors to CNS

Autonomic nervous system and functions

A component of the peripheral nervous system that:

1. regulates involuntary bodily functions, including heart rate, digestion, and respiratory rate, without conscious control.

2. Relays information from the central nervous system to internal muscles, glands and organs.

nervous systems in Autonomic Nervous System

1. Sympathetic nervous system

2. Parasympathetic nervou system

3. Enteric nervous system

Sympathetic nervous system and role

Part of the autonomic nervous system.

Immediately increases the bodily functions and activity at times of vigorous activity, stress or threat.

• Activates FFF response

parasympathetic nervous system

Part of the autonomic NS
Gradually decreases bodily activity of visceral muscles, organs and glands to maintain homeostasis.

enteric nervous system

Regulates gastrointestinal functions, controlling processes such as digestion, absorption, and gut motility, often referred to as the "second brain" due to its autonomy.

Conscious responses

Voluntary reactions to stimuli that involve awareness and intention, such as moving your hand to grab a glass.

Unconscious responses

Involuntary reactions to stimuli that occur without conscious awareness, such as reflex actions like pulling back a hand from a hot object.

Spinal reflex

An Involuntary, automatic response to a stimulus that involves neural information only reaching the interneuron in the spinal cord through the sensory pathway first and then activating a motor neuron to produce a quick reaction, bypassing the brain.

Eg. touching a hot pan

Visceral muscles

muscles involved in the activity of internal organs and glands like the intestines (also called smooth muscles)

skeletal muscles

muscles attached to bone and require motor messages to function

sensory neurons

Neurons that receive and carry sensory information from external and internal environments to the central nervous system

afferent

neural pathways that lead to the central nervous system and brain

motor neurons

Neurons that carry information from the central nervous system to skeletal muscles, organs and glands to stimulate activity

efferent

neural pathways that direct information away from the central nervous system towards relevant organs, glands, and muscles

soma

cell body

dendrites

transmit information to the soma

axon

transmits information from the soma to the axon terminals

axon terminal

branches at the end of the axon that

‘synapse’ with other cells

myelin

fatty substances that insulates axon allowing messages to travel faster

neurotransmitters

chemical substances that carry messages to other neurons, glands and muscles

synapse

site where neuron communication occurs

neurotransmission

communication between neurons by neurotransmitters binding to receptor sites of the post-synaptic neuron.

excitatory neurotransmission

excites postsynaptic neurons to promote activity

inhibitory neurotransmission

blocks or prevents post synaptic neuron activity

glutamates

main excitatory neurotransmitter of central nervous system that makes postsynaptic neurons more likely to fire that is involved in learning and memory.

gaba

primary inhibitory neurotransmitters in central nervous system that makes postsynaptic neurons less likely to fire.

interneuron

neurons that relay information between sensory and motor neurons

sensory receptors

sensory nerve endings that when stimulated, produce an afferent or sensory impulse

synaptic vesicle

a membrane- bound sphere filled with neurotransmitter molecules

synaptic gap

the space between the axon terminal of the presynaptic neuron and the membrane of the post-synaptic neuron

receptor site

a membrane protein on the dendrites of neurons that receive and detect specific neurotransmitters

neuromodulators

a subclass of neurotransmitters that alter the strength of neural transmission by increasing or decreasing the responsiveness of neurons to neurotransmitter signals

dopamine

a multifunctional neurotransmitter with both excitatory and inhibitory effects, is involved in many central nervous system functions such as movement, pleasure, attention, mood, cognition and motivation

reward pathway

a group of structures in the brain that are activated by rewarding or
reinforcing stimuli

serotonin

an inhibitory neurotransmitter that also acts as a neuromodulator, influencing a variety of brain activities

serotonin pathway

serotonin’s neuromodulatory system, which originates in the brainstem and extends to almost all areas of the cerebrum including the cerebral cortex

synaptic plasticity

changes that occur in the synapse between neurons leading to the strengthening or a weakening of neural connections.

Long-term potentiation (LTP)

the relatively permanent strengthening of synaptic connections as a result of repeated activation of a neural pathway

Long-term depression (LTD)

the relatively permanent weakening of synaptic connections as a result of repeated low- level activation

sprouting

the growth of axon or dendrite fibres at the synapse

dendritic spines

a dendrite fibre that grows by sprouting on the post-synaptic neuron

filigree appendages

a fibre that sprouts from the axon terminal of the presynaptic neuron

synaptogenesis

the formation of new synapses that result from sprouting

rerouting

the formation of new neural connections to establish alternative neural pathways

pruning

the removal of excess neurons and synaptic connections to increase efficiency of neuron transmissions

stressor

any event that causes you stress

stress

a state of mental, emotional, physiological tension resulting from a stressor

internal stressor

cause of stress that comes from within the individual and can be psychological or biological

external stressor

cause of stress that comes from outside the individual and can be environmental or sociocultural

acute stress

stress that usually occurs because of a sudden threat and only lasts for a short time

chronic stress

stress that lasts for a long time and can be detrimental to long term health

Flight or fight or freeze response

an automatic biological response to a perceived stressor that increases our chances of survival in our environment

cortisol

a hormone produced by the adrenal glands that regulates a wide range of bodily processes, including metabolism, and is released in response to stress

appraisal

the process of categorising an event on the basis of its perceived significance and how it may affect our wellbeing

General adaptation syndrome

a biological model of stress that proposes
we have a non-specific biological response to stress that occurs in three stages

Alarm reaction stage

the first stage of the general adaptation syndrome, in which we become aware of the stressor.

Consisting of two phases: shock and countershock

Shock

the first phase of the alarm reaction of the GAS, where the body’s ability to deal with the stressor falls below normal

Countershock

the second phase of the alarm reaction
of GAS, where the body’s ability to deal with the stressor rises above normal

Resistance stage

the second stage of GAS, where the stressor persists, and the body’s resources are maximised to cope and adapt over time

Exhaustion stage

the third stage of GAS, where the continued depletion of energy stores and high levels of cortisol decrease resistance to the stressor and supress the immune system

Transactional model of stress

a model that suggests a stress response is only elicited if an event is perceived to exceed our ability to cope and is based on our appraisal of the situation

Primary appraisal

when an individual determines whether a situation or event is significant to them and stressful or not

Irrelevant

when an event is not stressful: the event has no implications for an individual’s wellbeing because nothing will be gained or lost, or they are not invested in the situation

Benign/positive

when an event is not stressful: it is perceived as having a positive outcome for an individual. It either maintains or enhances their wellbeing

Threat

event is stressful: the anticipated harm/loss in the future because of an event

Harm/loss

event is stressful: the damage to the individual that has already occurred as a result of a stressor

Challenge

event is stressful: the perceived potential for personal gain or growth from an event

Secondary appraisal

when the event is stressful and an individual considers the available resources and their own coping strategies, to decide the best way of dealing with a stressor

coping

the things we do to manage and reduce the stress we experience

coping strategy

a method that we use to manage or reduce the stress produced by a stressor

Coping flexibility

the ability to modify our coping strategies to adapt and meet the demands of different stressful situations

context specific effectiveness

when a coping strategy matches or is appropriate to the stressful situation

approach strategy

an effort to confront a stressor and deal directly with it and its effects

avoidance strategy

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

Differences of Neurotransmitters and Neuromodulators

Neuromodulators:

• release into multiple synapses effecting 1+ post-synaptic neurons

• influences responsiveness of neurons to NT signals

• released slower but longer lasting effect

Neurotransmitters:

• effect one or two post-synaptic neurons

• in/decrease likelihood of firing

• released faster but shorter effect

Effects of cortisol

• Increases metabolism

• Energises body

• Suppresses immune system functioning

• Depletes bodily resources
  - increased vulnerability to diseases; colds, hypertension, diabetes

Gut-brain axis

Bidirectional communication link between CNS and ENS via Vagus Nerve

Explanatory power of GAS

Strengths
- identifies physiological processes
- suggests stress weakens ability to resist infection

Limitations
- overlooks individual differences
- research done on rats

Explanatory power of Lazarus and Folkman's Transactional Model of stress and coping

Strengths
- identifies psychological processes
- provides different methods of coping

limitations
- ignores physiological processes
- subjective therefore hard to test