Chapter 2 and 3 (nervous system and stress) Flashcards
Central nervous system (CNS)
Structure- Comprised of the brain and spinal cord.
Function- receives sensory information from the peripheral nervous system and sends motor information to the peripheral nervous system.
Neurons
A cell within the nervous system that transmits messages to and from the brain.
100 billion neurons in the brain
Grow 250000 of them a minute
Neural transmission can occur at 400km/h
The longest one can be one metre in length.
The brain
Regulates and guides all other parts of the nervous system
- Vital body functions like breathing, heart rate, and digestion
- Receiving info from the outside world via senses, coordinating an appropriate response.
- Higher-order functions like planning, thinking and learning
- Emotions, personalities, sense of humour
Spinal cord
Cable-like column of nerve fibres that extends from the base of the brain to the lower back and is encased by a series of bones called vertebrae
- Two-way highway
○ SAME
○ Sensory
○ Afferent (towards brain)
○ Motor
○ Efferent (away from brain)
Peripheral Nervous System
Structure- everything outside of the central nervous system including MOG (muscles, organs, glands)
Function- sends sensory info to the central nervous system. Receives motor information from the central nervous system.
Somatic nervous system (soma means body)
Network of neurons in the body that transmit information from receptor sites to the central nervous system, and then carry information to muscles to initiate voluntary movement.
Autonomic nervous system (ANS)
A network of neurons that carry information between the central nervous system, and the organs and glands, to ensure they are regulated without conscious awareness. (respiration…)
Parasympathetic (parachute) Nervous System (PNS)
- Maintains homeostasis (regulates body function)
- Returns body to a state of calm following stress
Sympathetic Nervous System (SNS)
- Prepares body for action to deal with potential threat
- Activates fight-flight-freeze
Neural Process
- sensory (afferent neurons at receptor site feel the sensation
- pass it along afferent pathways through the peripheral nervous system and then central via the spinal cord, toward the brain.
- interneurons in the brain communicate with motor neurons
- motor neurons send a signal via efferent pathways to an effector site- the muscle
Fight-flight-freeze response
Initiated by the sympathetic nervous system and prepares the body to confront a stressful situation to optimise the chance of survival.
- Fight- stay/attack
- Flight- run
- Freeze- go unnoticed
Motor neurons
- Transmit motor information from your body to your brain
- They do this via efferent pathways (efferent means away)
Sensory neurons
- Transmit sensory information from your body to your brain
- They do this via afferent pathways (afferent means towards)
Interneurons
- Transmit information between sensory and motor neurons
- They are the most numerous neurons in the brain
- They are not found in the PNS
Spinal reflex
The body’s ability to respond and react to pain. An automatic response that is initiated by neurons in the spinal cord, independent of the brain.
- When? Pain aid survival
- How? intercepted by interneurons
- Why? Faster reaction.
Dendrite
Receives incoming neural messages
Soma
The body of the neuron, contains the nucleus with the genetic material for the neuron.
Axon
The pathway down which the neural message travels
Myelin sheath
Fatty tissue that encases the axon to aid in the speed of transmission, protects from interference
Axon terminals
Exit pathways for neural messages to make their way to the next neuron
Terminal buttons
Releases a chemical substance known as a neurotransmitter to a receiving neuron for communication purposes; also referred to as synaptic knobs.
Neurotransmission
The process of communication between neurons using electrochemical energy.
1. Neural impulse runs from dendrite to axon terminals
2. Synaptic knobs release a chemical substance
3. This neurotransmitter crosses the synapse (space from one neuron to the next)
4. The neurotransmitter is picked up by the next neuron’s dendrites.
synaptic gap
the space between the presynaptic neuron and the postsynaptic neuron
Neurotransmitter
The chemical substance released by the terminal button of a neuro, is necessary for neural communication.
- Each neurotransmitter binds with a specific type of receptor
Excitatory neurotransmitter
Increasing the likelihood that the neuron will fire an action potential
- Glutamate- memory and learning, allows our brain to change neurons as we learn
Inhibitory neurotransmitter
Decreasing the likelihood that the neuron will fire an action potential
- GABA- calming feelings of anxiety, fear and stress
Neuromodulator
A chemical messenger that enhances signal transmission
- Effective on groups of neurones
- Dopamine- motivation and motor movement
- Serotonins- mood stabiliser, wellbeing and happiness
Neuro Plasticity
The ability of the brain to physically change in response to experience.
- Developmental- occurs naturally across the lifespan.
○ Certain critical periods
- Adaptive- occurs as a result of brain damage or trauma
○ Uses critical periods to enable adaptive plasticity
Synaptic plasticity
The ability of synaptic connections to change over time in response to activity or experience.
Long term depression
The long-lasting and experience-dependent weakening of synaptic connections between neurons that are not regularly activated
The reduction in the efficiency of those neural connections.
Long term potentiation (LTP)
The increase in synaptic strength through high-frequency stimulation of the neural pathway.
The long-lasted and experience-dependent strengthening of synaptic connections that are regularly activated.
- Hebb’s rule
- Muscle memory
- More dendrites and more knobs which means more neurotransmitters.
- Physical changes in the neurons
Sprouting
The ability of dendrites or axons to change over time in response to activity or experience (creating new connections)
Neural processes
Proliferation- creating neurons (when born)
Migration- they need to move to the areas in which they are needed the most
Circuit formation- find a buddy and create a synapse
Circuit pruning- if they aren’t going strong
Myelination-if they are going strong
Rerouting
The ability of a neuron that is connected to a damaged neuron to create an alternate synaptic connection. (establishing pathways and finding alternate ones)
Pruning
The elimination of synaptic connections that are not adequately activated. (removing old connections that aren’t being used.
Hebb’s rule
Neurons that fire together, wire together
stress
A state of psychological and physiological state of tension in response to a stimulus
Eustress
A form of stress characterised by a positive psychological state
Distress
A form of stress characterised by a negative psychological state
Acute stress
A form of stress characterised by intense psychological and physiological symptoms that are brief
Chronic stress
A form of stress that endures for several months or longer
Stressor
The stimulus that prompts stress
- Internal
○ Stimulus from within
○ Hungry
○ Illness
○ Low self-esteem
- External
○ Environmental stimulus
○ Upcoming exam
○ Relationship conflicts
○ Being overworked
Cortisol
A hormone released in times of stress to aid the body in initiating and maintaining heightened arousal
- Increase glucose to help bodily functions repair damage
- Gives high energy
- More prominent during chronic stress
- Body’s defence mechanism
Psychosomatic illness
Psychological factors can result in physiological symptoms
Selye’s General Adaptation Syndrome
Explains stress from a BIOLOGICAL perspective.
SCARE
Shock
Counter shock (adrenaline)
Alarm reaction
Resistance (cortisol)
Exhaustion
levels of resistance to stress across a period of time.
Lazarus and Folkman’s transactional model of stress and coping
Explains stress as a subjective transaction between incoming stressors, and the personal and environmental factors specific to an individual.
Explains as a PSYCHOLOGICAL process
Primary Appraisal
Individual’s assessment of a situation.
Split into 3 kinds of stress
- Harm/loss
- Threat
- Challenge
Harm/loss
Has happened
Threat
Could happen
Challenge
Provides a good opportunity for growth
Secondary appraisal
Individual’s assessment of resources to deal/cope with demands
- Internal (character)
- External (support network)
coping
the process of dealing wth stressors
strategies for coping
Exercise- uses adrenaline that is released when stressed, stops cortisol from being needed
Meditation/relaxation- reduce physiological responses, slow cortisol release
Social support- less likely the demands will outweigh the stress
Alcohol/drugs- dopamine hit
Approach strategy
Behaviours that attempt to decrease stress by addressing or finding solutions to the problem
- For example, lose a job? Apply for one
- Typically a healthy response
Avoidance strategy
Failing to engage or deal with the stress by protecting yourself from the distress
- Ignoring/denying the situation
- Typically maladaptive/unhealthy for the individual
Self-efficiency
The belief in our own ability and that our actions can influence outcomes
Resilience
Our ability to bounce back following adversity
Context-specific effectiveness
When the coping strategy used is appropriate for the unique demands of the stressor
Being a good fit for certain situations
coping flexibility
The ability for someone to look at what is ineffective and replace it with something more effective.
e.g.- this isn’t working, I need to change
