Unit 3- AOS1 : How does the nervous system enable psychological functioning? Flashcards
How does the nervous system enable psychological functioning?
Central Nervous System
The brain and the spinal cord; processes and coordinates responses to sensory stimuli.
Identify the two components of the central nervous system (CNS)?
The two components of the central nervous system are the brain and the spinal cord.
Use and example to explain the two main functions of the CNS?
Touching a hot stove (sensory input) causes the CNS to signal muscles in the arm to withdraw (motor output).
How does the brain communicate with the body?
The brain communicates with the body through the spinal cord and nerves to the muscles and organs.
Describe the structure of the spinal cord?
The spinal cord is a 45-centimetere long extension of the brain stem. It is composed of nerve fibers and is directly linked to the peripheral nervous system by 31 pairs of spinal nerves.
Explain the difference between the afferent and efferent pathways that the spinal nerves are connected to.
Afferent-ascending caries out sensory information gathered by our five senses to the brain whereas efferent carries motor commands from the CNS to the skeletal muscles.
Use and example to explain the two roles of the spinal cord
Touching a hot stove sends pain signals from the hand up the spinal cord to the brain. The spinal cord initiates quick, involuntary action like pulling the hand away before the pain signal even reaches the brain.
What is a spinal reflex?
An involuntary and unconscious response to a stimulus involving the spinal cord, which occurs without input from the brain.
What is sensory receptors?
Are a sensory nerve ending that produces an afferent or sensory impulse when stimulated.
What is a sensory neuron?
A nerve cell that carries sensory signals throughout the nervous system.
What is the interneuron?
A nerve cell in the spinal cord that connects motor and sensory neurons by relaying information between the two.
What are the motor neurons?
A nerve cell that transmits motor impulses from the spinal cord to the skeletal and smooth muscles.
Why is a spinal reflex considered to be an unconscious response?
A spinal reflex is an involuntary and unconscious response to a stimulus involving the spinal cord and occurs without input from the brain.
Therefore, spinal reflexes occur without conscious awareness.
Explain the role of sensory receptors in the spinal reflex
Sensory stimulus is detected by the sensory receptors.
Explain the role of sensory neurons in a spinal reflex
Sensory neurons transmit the sensory information about the stimulus towards the spinal cord.
Explain the role of interneurons in the spinal reflex
In the case of the spinal reflex, an adaptive motor response is initiated by the interneurons without input from the brain to respond more quickly to the threat detected by the sensory receptors.
Explain the role of motor neurons in a spinal reflex
Information about the motor movement is then relayed to the motor neurons, which transmit the motor impulses from the spinal cord to the skeletal and/or visceral muscles.
What is the peripheral nervous system made up of, in terms of cells and structures?
The peripheral nervous system consists of all the nerves outside of the CNS, including cranial nerves that extend from the spinal cord and brain.
The peripheral nervous system has two main subdivisions: the somatic nervous system and the automatic nervous system.
What is the main role of the peripheral nervous system?
Its main role is to carry messages between the CNS and muscles, organs and glands throughout the body.
Name the two subdivisions of the peripheral nervous system
The somatic nervous system and the automatic nervous system.
Describes the two ways that the somatic nervous system enables communication between the CNS and body
The somatic nervous system carries motor (efferent) information from the CNS to the body.
This involves the motor (efferent) neurons in the somatic nervous system that are responsible for voluntary movements and communicating movement information back to the body.
Sympathetic Nervous System
Is dominant in response to perceived threats and stressful psychological and physiological stimuli. It increases arousal, readying the body for a quick response.
What is the role of the autonomic nervous system?
Controls the body’s internal environment in an automatic or self-regulated manner.
It is responsible for basic life processes such as heart rate, reparation, digestion and blood pressure.
What is meant by the autonomic nervous system being self regulating?
Meaning that it performs most of it functions without conscious awareness.
Provide two examples of bodily functions the autonomic nervous system regulates
Heart Rate, Digestion
Name the two sub-divisions of the autonomic nervous system
Sympathetic and Parasympathetic Nervous System
Why is the sympathetic nervous system dominant when we respond to threats and stressful situations.
This is because one of the main roles of the sympathetic nervous system is to increase arousal and ready the body for a quick response. In a stressful or threatening situation, the increased arousal helps prepare to deal with the situation.
Provide two examples of response the sympathetic nervous system may perform to increase our arousal in response to a threat
Pupils dilating to allow more light into the eye to see better and heart rate, blood pressure.
Breathing rates increasing accelerated oxygenated blood flow to the muscles in order to respond to the threat.
Increased sugars and fats being released into the blood to provide energy for quick action.
Outline the two main functions if the parasympathetic nervous system using examples.
Maintaining balance by regulating blood sugar and energy levels & counterbalancing the energizing function of the sympathetic nervous system by lowering arousal and restoring the body to a calm state after a threat has passed.
What is the role of neurons in the nervous system?
The role of neurons is the transmission of information throughout the nervous system.
What are neurotransmitters and what do they do?
Neurotransmitters are chemicals produced by neurons that carry messages to other neurons or cells withing the nervous system, including muscle organs and glands.
Describe how information is transmitted across a synapse
When an action potential travels down an axon and into an axon terminal, it creates chemical changes within the terminal.
This causes the synaptic vesicles to merge with the membrane at the terminal and release the neurotransmitters into the synaptic gap.
Neurotransmitters travel across this gap towards the receptor sites on the dendrites of the post neuron.
They attach or bind to the receptor’s sites, which are specialized to receive specific neurotransmitters.
Name a excitatory neurotransmitter
Glutamate
What is meant by an excitatory effect in relation to neurotransmitters?
Excitatory neurotransmitters increase the likelihood that the post-synaptic neuron will fire an action potential or neural impulse, thus having an excitatory effect on the post- synaptic neuron.
Describe the role of glutamate when learning something new and storing a memory of it.
Glutamate plays an important role in learning and forming memories in the brain by stimulating essential structural and functional changes to the connections between neurons.
Name an inhibitory neurotransmitter
Gamma-aminobutyric acid (GABA)
What is meant by an inhibitory effect in relation to neurontransmitters?
Inhibitory neurotransmitters decrease the likelihood that the post-synaptic neuron will fire an action potential or neural impulse, thus having an inhibitory effect on the post synaptic neuron.
What is the role of GABA within the nervous system?
It suppresses or slows down post-synaptic neuron activity, decreasing their likelihood of firing.
Why does the brain (CNS) require that different neurotransmitters such as GABA and glutamate are in balance?
Because without sufficient levels of the inhibitory neurotransmitter GABA, activation of the post synaptic neurons may get out of hand because the excitatory effects of glutamate take over, leading to mental disorders such as anxiety.
Provide two differences between glutamate and GABA
Glutamate is the primary excitatory neurotransmitter in the CNS, and it activates or stimulates neural activity in the brain whereas GABA is the primary inhibitory neurotransmitter in the CNS, and it suppress or slows down neural activity in the brain.
Why is dopamine considered to be a neuromodulator?
Dopamine is a neuromodulator because it reinforces the neural activity in regions of the brain associated with these functions, for example reward pathways.
What is the reward pathway and what is its function?
The reward pathway refers to a group of structures in the brain that are activated by rewarding or reinforcing stimuli, such as seeing a cupcake if you’re hungry. The pathways control our responses to natural rewards.
What happens to dopamine levels in the reward pathway when someone is exposed to a rewarding stimulus or anticipates one?
When we are exposed to rewarding stimuli, the brain increases the release of dopamine. The more dopamine that is released, the more a stimulus is sensed as a reward.
What happens to dopamine levels in the brain after we drink liquid of any kind?
When we drink water there is a large surge of dopamine that is released compared to when water isn’t drunk but injected there wasn’t that release of dopamine.
Why is hunger considered to be a motivational sensation?
The consumption of food releases dopamine and gives feeling of pleasure, therefore increasing our chances of eating food the next time and giving motivation.
Describe how dopamine modulates appetite or hunger?
Hunger results from a decrease in the baseline dopamine levels in our brain. This decrease is thought to trigger a series of reactions in the brain, increasing dopamine-dependent behaviors such as seeking out food and eating it.
Describe the serotonin pathway
Serotonin’s neuromodulatory system, which originates in the brainstem and extends to almost all the areas of the cerebrum including the cerebral cortex.
Describe the link between serotonin and depression
When levels of serotonin dip too low, this has an effect on the brain’s ability to regulate mood, because low serotonin levels are usually associated with depression and anxiety and high serotonin is associated with being calm, focused and happy.
Explain the term of synaptic plasticity
Specific changes that occur within the synapse, between neurons.
Explain the role of synaptic plasticity in learning and memory formation
Glutamate is released each time a neural pathway associated with an experience is activated.
Given that glutamate is an excitatory neurotransmitter, it stimulates activity in a pathway and promotes neural connectivity in general.
Distinguish between the process of LTP and LTD
Long term potentiation is the relatively strengthening of synaptic connections as a result of repeated activation of a neural pathway whereas
Long term depression is the relatively permanent weakening of synaptic connections as a result of lack activations.
Explain how LTP and LTD work together to make neural pathways more efficient
LTP and LTD work together to make neural pathways more efficient through neural plasticity by the brain and its neural networks to change, grow and organize itself.
Describe two modifications that occur as a result of sprouting at the synapse
Sprouting involves the growth of axon and/or dendrite fibers. There would be growth of dendritic spines on the post-synaptic neuron and growth of filigree appendages on the axon terminal.
Explain the difference between sprouting and pruning
Sprouting is the growth of axon or dendrite fibers at the synapse whereas pruning is the removal of excess neurons and synaptic connections to increase the efficiency of neuronal transmission.
Explain the role of rerouting when learning and forming memory
Rerouting is the formation of new connections between neurons to establish alternative neural pathways.
Rerouting is a vital process in learning and memory formation, allowing the brain to adapt, compensate for damage, enhance memory storage, facilitate skill acquisition, integrate new information, and support the strengthening of neural connections.
Define ‘Stress’
A psychobiological process, that is a state of mental, emotional and physiological tension in response to something that is a stressor.
Use an example to explain why stress is considered to be a psychobiological process
Stress is a psychobiological process because it includes both biological and psychological responses.
A student might perceive their upcoming exam as stressful causing them to be anxious about it. These feelings and thought might then cause their heart to race and get a stomachache as the body release cortisol.
The students’ psychological thoughts cause physical reactions, and this can be an ongoing cycle where the body and mind are influencing each other.
Use an example to explain the relationship between stress and a stressor
Stressor is any event that causes stress or is perceived as a threat and a challenge to our ability to cope where stress is a state of mental, emotional and physiological tension, resulting from a stressor.
An example would be of a stressor would be missing the bus when you have an important interview, and the stress would be the fear of being late creating anxiety and elevating stress levels.
Distinguish between internal and external stressor.
An internal stressor is a cause of stress that originates within an individual; can be both psychological and biological/physiological where an external stressor is a cause of stress that originates outside of an individual, such an event or extreme environment.
What are internal stressors
Expectations, mindset, feeling, pain, illness and sleep deprivation.
Describe acute stress and provide an example
Acute stress is stress that usually occurs because of a sudden threat and only last for a short time. Acute stress can be beneficial since it helps deal with the challenge better. For example, having an exam you’re worried about.
Describe chronic stress and provide an example
Chronic stress usually involves stress felt constantly and a prolonged amount of time. For example, having financial problems such as being in debt for a long time.
Explain why chronic stress is detrimental to our ongoing physical and mental health
Chronic stress is detrimental to the body since it can suppress the immune system, upset the digestive and reproductive systems as well as making individuals more vulnerable to anxiety and depression.
What is the flight-flight-or-freeze response and why is it adaptive?
The fight-flight-or-freeze response is an automatic biological response to a perceived stressor that increases our chances at survival in our environment.
It is adaptive because it minimizes possible harm and enables us to deal with the stressor most effectively by instinctively adapting either fight, flight or freeze.
Why is flight-flight-or-freeze considered to be an example of acute stress
Flight-flight-or-freeze is considered to be acute stress because it usually happens rapidly, and only for a limited amount of time, allowing the body to return to its balanced state once the threat has been resolved.
Give physiological changes and the adaptive benefits of these changes
Increased heart rate, breathing rate, blood pressure- To quickly transport oxygenated blood to the muscles in our extremities to prepare for action.
Dilated Pupils- To increase the amount of light entering the eyes to potentially see more clearly.
Increased sweat production- To keep the body cool when increased energy is expanded.
Provide one similarity and one difference between a flight or fight response and a freeze response
The flight or freeze response is when the sympathetic nervous system is dominant whereas the freeze response is when the parasympathetic nervous system is dominant. One similarity is that they are both adaptive.
What is cortisol?
Cortisol is the stress hormone that is produced and released from the adrenal cortex that allows the body to continue to stay on high alert over a long period of time.
List the general functions of cortisol within the body
Cortisol regulates metabolism and the immune response. Cortisol also modifies the body’s glucose level, acts as an anti-inflammatory agent and influences blood pressure.
How does cortisol benefit us in time of stress
-Boosting our energy levels and increasing blood glucose levels
-Heightening our alertness, increasing the brains use of glucose
-Increasing the body’s ability to repair tissue.
Why is having high levels of cortisol in the body for a prolonged period problematic?
Having high levels of cortisol for a prolonged amount of time can be problematic because cortisol suppress the immune system, and when released for a prolonged amount of time it can cause risk of cancer and autoimmune diseases as well anxiety and depression.
What is the gut-brain axis (GBA)?
The gut-brain axis refers to the connection between the central nervous system and enteric nervous system, that enables bidirectional communication between the brain and the gastrointestinal tract.
What is meant by the GBA being able to communicate in a bidirectional manner?
This means that communication can occur is both directions, from the brain to the gut and the gut to the brain.
Which nervous system is the enteric nervous system (ENS) a sub-system of?
The enteric nervous system is a sub system if the autonomic nervous system.
What is the ENS made of?
It consists of 200-600 million sensory, motor and interneurons that line the gastrointestinal tract.
List three functions of the ENS
-Coordinates rhythmic muscle contractions that move materials along the digestive tract
-Regulates gastric acid secretion
-Regulates the release of gut hormones; and it interacts with the immune system.
Describe the vagus nerve
The vagus nerve is a nerve that connects the brain (central nervous system) to organs within the autonomic nervous system, via nerve fibers that directly link organs such as the heart, lung and intestinal tract.
Why is the vagus nerve an important part of the GBA?
The vagus nerve plays an important role in the GBA because the bidirectional communication that occurs between the CNS and ENS happens via the vagus nerve and gut microbiota.
What is gut microbiota and what is their main function?
Gut microbiota is the microbe population found in the gut (digestive system) and its main function is to digest food to provide both themselves and us with nutrients.
How are gut microbiota linked to neurotransmitter levels in the brain
Gut microbiota is involved in the production of some neurotransmitters, which can affect the concentrations of related neurotransmitters in the brain.
How do increased stress and high levels of cortisol affect our gut microbiota?
High levels of stress with increased cortisol levels can lead to changes to gut microbiota, associated with anxiety and depression.
What did Selye mean when he described the GAS as being non-specific?
Meaning that it is the same irrespective of the type of stressor the organism is exposed to.
Describe what occurs in the alarm reaction of the GAS, including distinction between the shock and countershock phases.
In the alarm reaction of the GAS model, this is the stage where individuals become aware of the stressor and the body reacts to the immediate threat or challenge.
This stage has two phases: shock and countershock.
In the shock phase, an acute stress response occurs, whereby the body experiences a drop in its resistance, and the ability to deal with the stressor below normal. (decrease in temperature, blood sugar levels)
In the countershock phase, the body tries to compensate for the acute stress response in the shock phase. This is helped by the release of cortisol as well as the activation of flight-flight or freeze in order to deal with the stressor. The alarm reaction usually doesn’t last very long.
Describe what happens during the resistance stage of GAS
During the resistance stage of GAS, the body is actively trying to deal with the stressor. During this stage the body’s ability to deal with the stressor and resistance rises above normal.
Cortisol levels are at their highest, which helps repair any damage to the body and maximize the body’s resources to cope and adapt to the stressor over time.
Describe the circumstances under which someone would enter the resistance stage of the GAS
For someone to enter the resistance stage of GAS the stressor persists over a prolonged period and the individual has to adapt to its ongoing presence.
With reference to cortisol explain why the body begins to show signs of wear and tear in the resistance stage.
During the resistance stage is when cortisol is at it highest this interferes with the body’s ability to fight disease by suppressing the immune system.
Which will eventually cause the body to show signs of physiological wear and tear like the cold and flu symptoms, sore throats and headaches.
Describe the key features of the exhaustion stage of GAS.
During the exhaustion stage the body runs out of reserve because it has been fighting the stressor for so long. The body may become weak and have a low resistance to physiological and psychological illnesses.
One limitation and one strength of the GAS model
Strength- The model suggests a predictable pattern of responses that can easily be tested in a laboratory.
Limitation- Rats and humans are physiologically different. Humans stress can be more complex meaning that the model cannot truly be generalized to humans.
What does appraisal involve?
Appraisal is the process of categorizing an event on the basis of its perceived significance and how it may affect our wellbeing
What is involved in primary appraisal?
In primary appraisal the induvial determines whether the situation or event is significant to them. Based on this the event is categorized as stressful or not stressful.
If it’s not stressful it will either be irrelevant or benign/positive.
If it’s stressful it will be either a threat, harm/loss or challenge.
Distinguish between begin/positive and irrelevant.
Benign/positive means that the outcome of the situation is perceived as positive either maintained or enhances the wellbeing.
Irrelevant means that the situation has no implications for the individual. Meaning that nothing is gained or lost by the event.
How does secondary appraisal differ from primary appraisal in the transactional model of stress and coping?
The secondary appraisal is where individuals consider the available resources and their own coping strategies to decide the best way of dealing with stress whereas the primary appraisal is where the individual and event or situation is significant to that and stressful or not.
One strength and limitation of the transactional model of stress and coping
Strength- The model acknowledges psychological determinants or causes of the stress response
Limitation- It is hard to test through experimental research because of the subjective nature of individual response to stress.
Define ‘coping’
Coping is the term used to describe all the things individuals do to manage and reduce the stress we experience.
What is a coping strategy?
A coping strategy is a method that individual use to manage or reduce the stress produced by a stressor
What are the two things that affect whether a coping strategy works or not?
-Coping flexibility and context-specific effectiveness
Distinguish between context specific effectiveness and coping flexibility
Coping flexibility is the ability to modify coping strategies in order to meet the demands of different stressful situations whereas context specific effectiveness is when a coping strategy matches or is appropriate to the stressful situation.
What are approach strategies? Provide an example
Approach strategies are an effort it confronts a stressor and deal directly with it and its effects. An example would be when you get into an argument with your friend you try and talk to them to reach a solution.
What are avoidance strategies? Provide an example
Avoidance strategies are an effort to avoid a stressor and not directly deal with it and its effects. I f you and your friend get into an argument you try and avoid the issue and ignore them.
Outline one benefit and one limitation of using approach strategies to cope with stress
Benefit- Approach strategies are usually more effective and adaptive that avoidance strategies.
Limitation- In the short-term approach strategies may cause an increase in stress levels when individuals are dealing with the stress directly
Outline one benefit and one limitation of using avoidance strategies to cope with stress
Benefit- It allows you to conserve energy to focus on other stressors that can be changed
Limitations- Avoidance strategies tend to be maladaptive.
