The Human Nervous System- Psychology

What are the main three functions of the nervous system?

Receive information, process information, coordinates a response.

What is the central nervous system?

It is comprised of the brain and spinal cord. It receives neural messages from and transmits neural messages to the PNS.

What are the main functions of the CNS?

Receive sensory info from the body and send it to the brain, transmit motor info from the brain and send to the relevant parts of the body.

What are the functions of the brain?

Processes info received through neural pathways from the body and directs actions within the body.

What are the functions of the spinal cord?

Thin long bundle of nerve fibres, a route via which neural info travels between the brain and body.

What is the peripheral nervous system?

Comprised of every neuron in the body outside the CNS.

What are the main functions of the PNS?

Carries info from the CNS from body’s muscle organs and glands and sensory organs.

What is the autonomic nervous system?

Regulates visceral muscles, organs and glands, and transmits neural messages to the CNS about their activity, autonomous.

What is the somatic nervous system?

Network of nerves that carry sensory info to the CNS and motor from the CNS.

What is the sympathetic nervous system?

Activates activity of most visceral muscles, organs and glands in times of vigorous activity, stress or threat.

What is the enteric nervous system?

The network of nerves in the gut, controls the function of the gastrointestinal.

What is the parasympathetic nervous system?

Maintains the optimal and balanced functioning of most visceral muscles, organs and glands.

What are some sympathetic examples?

Pupil dilation, fast heartbeat, bladder relaxation.

What does the CNS do in relation to spinal reflex?

Can initiate some simple motor reactions in the form of reflexes that can occur rapidly and independently of the brain.

What is spinal reflex?

An unconscious, involuntary and automatically occurring response to sensory stimuli without any involvement of the brain.

What is the process of spinal reflex?

1. Sensation of the stimulus is detected by sensory receptors and sensory neurons relay messages to the spinal cord.

2. The interneurons in the spinal cord immediately send a signal via motor neurons to initiate an unconscious motor response in the skeletal muscles of the body part.

3. This occurs prior to the sensory info being received in the brain and there is conscious awareness of the feeling of the stimulus.

What is the somatic conscious response?

-A deliberate and voluntary action that is initiated by the brain and performed intentionally by the body.

-Enabled by the somatic nervous system (PNS) and the spinal cord and brain (CNS).

What is the conscious response process?

1. Sensory stimuli is detected by sensory receptors.

2. Sensory messages sent via afferent neurons to the spinal cord and brain.

3. The brain initiates a motor response.

4. The efferent neurons carry messages from CNS to the skeletal muscles.

5. Motor message (efferent) is transmitted by the skeletal muscles to carry out the conscious motor response.

What are neurons?

Individual nerve cell that is specialised to receive, process and transmit information to other cells in the body.

(Types of neurons) What is a sensory neuron?

Send information from sensory receptors from the PNS to the CNS.

What is a motor neuron?

Send information about motor movement to the PNS (muscles, organs and glands) from the CNS.

What are interneurons?

Communication link; Carries information between sensory and motor neurons.

What are dendrites?

Extensions of a neuron that detect and receive information from other neurons.

What is myelin?

Fatty substance that surrounds and insulates the axon, allows for the rapid movement of the message along the axon and prevents interference from other neurons.

What is the axon?

Carries message towards the axon terminal.

What is the axon terminal?

Store and secrete neurotransmitters.

What is the first step of neural synapse transmission?

Neurotransmitters are produced and released from the axon terminal and released into the synaptic gap (cleft).

What is the second step of neural synapse transmission?

Neurotransmitters bind to receptor sites on the dendrites on the post synaptic neuron.

What is the third step of neural synapse transmission?

If it binds the post synaptic neuron will have an excitatory or inhibitory effect.

-If binding does not occur, the neurotransmitter will be reabsorbed into the presynaptic neuron.

What is a neurotransmitter?

A chemical molecule that has an effect on one or two postsynaptic neurons.

What is an excitatory effect?

When the neurotransmitter stimulates or activates the postsynaptic neuron, increasing the likelihood of firing.

-Glutamate is the most common excitatory neurotransmitter.

What is an inhibitory effect?

When the neurotransmitter blocks or prevents the postsynaptic neuron, decreasing the likelihood of firing.

-GABA is the most common inhibitory neurotransmitter.

What is a neuromodulator?

A chemical molecule that has an effect on multiple postsynaptic neurons.

What is dopamine?

-Neuromodulator primarily responsible for voluntary motor movement, the experience of pleasure, and reward-based learning.

-Can have both excitatory or inhibitory effects.

What is serotonin?

A neuromodulator primarily responsible for the regulation of mood and sleep.

-Inhibitory effect (does not stimulate brain activity).

What is synaptic plasticity?

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

-Changes allow strengthening or weakening of connections between neurons at synapse.

What is sprouting?

Dendrites or axons develop new extensions or branches. Allows formation of new synaptic connections.

What is rerouting?

Ability of a neuron that is connected to a damaged neuron to create an alternative synaptic connection with an undamaged neuron.

What is pruning?

The elimination of synaptic connections that are not adequately activated. This is necessary for stronger and more essential connections enhancing brain functioning.

What is learning?

The process of acquiring knowledge, skill, or behaviours through experience.

What is memory?

Encoding, storage and retrieving information that has been previously encountered.

What is long term potentiation?

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

What is long term depression?

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

What is stress?

A psychological or physiological experience that occurs when an individual encounters something of significance that demands their attention.

What is an internal stressor?

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

What is an external stressor?

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

What is eustress?

A form of stress characterised by a positive psychological state.

What is distress?

A form of stress characterised by a negative psychological state.

What is the flight-fight-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 (adaptive response).

What are some psychological responses to prepare for a flight-fight-freeze response?

Increased heartrate/blood pressure and increased perspiration.

What is cortisol?

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

-This can be seen as the second wave response to the initial stressor, helping the body to remain at above average levels of arousal.

-Increase cortisol in the bloodstream over aa long time, impairs the immune system, thereby increasing vulnerability to developing more illness/disease.

What is General Adaption Syndrome (GAS)?

A biological model involving three stages of physiological reactions that a person experiences in response to a persistent stressor.

-All stressors cause a non-specific stress response. (Biological response to stress)

What is stage 1 of GAS?

Alarm reaction:

Temporary state of shock followed by counter shock/activation of sympathetic nervous system.

What is stage 2 of GAS?

Resistance:

This applies if the stressor is not dealt with immediately and the body requires more energy to cope with and adapt to the stressor.

What is stage 3 of GAS?

Exhaustion:

If the stress still continues, the body cannot sustain its resistance, and the effects of the stressor can no longer be dealt with.

Resources are depleted, organism becomes vulnerable to physical and mental disorders.

What are the strengths of GAS?

-Recognise a predictable pattern of physiological responses associated with distinct stages and substages, which can be measured in individuals.

-Recognises the relationship between chronic stress and illness.

What are the limitations of GAS?

-Based on research that was conducted on rats, reducing generalisability.

-Only focuses on the biological aspects of stress (ignores physiological factors).

What is Lazarus and Foinman’s transactional model of stress and coping?

-Model to describe and explain individual differences in stress response from a psychological perspective.

-This model proposes that stress involves an encounter (transactional) between an individual and their external environment, and that a stress response depends on the individuals’ interpretation (appraisal) of the stressor and their ability to cope with it.

What is primary appraisal?

The initial process of evaluating the nature of an incoming stressor, specifically the kind of stress it might cause.

What are the outcomes of primary appraisal depending on whether the situation is:

-Irrelevant (not presenting an issue or source of worry)

-Benign-positive (stimulus perceived as neutral or positive)

-Stressful (a source of worry or significance for an individual)

If its deemed to be stressful, leads to further appraisal:

-Harm/ loss (assessment of how much damage has already occurred since the stressor occurred-past)

-Threat (assessment of harm/loss that hasn’t occurred yet but could occur in the future)

-Challenge (assessment of potential for personal gain or growth - future)

What is secondary appraisal?

The process of evaluating the resources required and available to cope with a stressor.

How can primary appraisal outcomes be seen as distress?

-Both harm/loss and threat can be seen as distress.

-Challenge can be used as distress.

What are the strengths of the Lazarus and Foinman’s model?

-L and f focuses on the psychological determination of stress that we have control over.

-Allows for the fact that stressors and circumstances can reoccur overtime (appraisal).

What are the limitations of the Lazarus and Foinman’s model?

-Difficult to test the mode, through experimentation. This is because of the subjective nature, vulnerability and complexity of the human stress response.

-Difficult to isolate variables.

-Doesn’t account for or include physiological responses.

What is the Gutbrain Axis (GBA)?

What is the gut?

A long flexible tube from the mouth to the anus.

What is the gutbrain axis?

-Refers to the bidirectional correlation between the gut and the brain through the enteric and CNS.

-The nerves within the enteric nervous system communicate with nerves in the CNS and vice versa.

-The communication occurs through the vagus nerve (longest nerve in the human body from the brain stem to the intestines).

What is microbiota?

-Refers to microorganisms that live in the gut.

-Research suggests that there are potential links between the gut and experiences of stress, the presence or absence of mental illness, learning, memory, body weight and behaviour.

-A diverse gut microbiota (many kinds of different microorganisms, results in better gut health and therefore greater levels of overall health.

What are the findings of germ free animal studies?

-Significant changes in anxiety like behaviour and anxiety responses.

-Proper memory function.

-Increased secretion of stress hormones.

What is microbiota composition in humans?

-Microbiota in healthy individuals was compared to individuals with different psychologists or behavioural patterns or experiences.

-Findings- composition of gut microbiota can influence the likelihood of experiencing: ASD, cognitive decline and stress.

What are gut release diseases?

Potential links between gut related diseases, IBS and inflammatory bowl diseases and presence of anxiety and depressive symptoms.

What is coping?

The process of dealing with stress.

What is context specific effectiveness?

When the coping strategy used is appropriate, a good match for the demands of the stressor.

What is coping flexibility?

Individual’s ability to adjust or change their coping strategies to meet the changing demands of the stressor.

What are ‘approach’ strategies?

Strategies that directly confront the source of stress.

What are avoidant coping strategies?

Strategies that evade the stressor, seeking to indirectly reduce stress.

How does coping strategies relate to resilience?

-If we have high levels of resilience, we are more likely to seek coping strategies that confront and deal with the stressor, approach coping strategies, context-specific effectiveness, as well as adapting our coping strategies if they aren’t working anymore (coping flexibility).
-If we have lower levels of resilience, we might be more likely to engage in avoidance coping strategies.