Unit 3 AOS 1: How does the nervous system enable psychological functioning Flashcards
Nervous System
Consists of
- Central Nervous system
- Peripheral Nervous system
CNS function
the primary function is to process information received from internal and external environments and to activate appropriate responses.
Consists of
- Brain and Spinal cord
Brain function
The brain Receives and analyses sensory information, responding by controlling all bodily actions and functions.
Many brain functions involve the activation of neural pathways that link different brain areas and structures.
What is a neural pathway?
a neural pathway comprises of one or more circuits of interconnected neurons that form a communication network
spinal cord
the spinal cord is long thin bundles of nerve fibres, it is encased in a series of bones called vertebrae. The spinal cord links the brain and parts of the body below the neck.
How does the spinal cord receive sensory information
sensory information is received from the body (via the peripheral nervous system) and the send these messages to the brain (afferent)
How does the spinal cord receive motor information
Motor information is received from the brain, where it is then sent (efferent) to relevant parts of the body (via the peripheral system) so that appropriate actions can be taken
if spinal cord is injured
if spinal cord is injured the connection to the brain can be severed meaning we can lose both sensory input and control of our body
how does a spinal reflex work?
Sensory receptors send messages to spinal cord which initials a neural message. the spinal cord receives the message and connects to an interneuron or motor neuron. Then an instant response takes place (movement).
unconscious behaviours
spinal reflexes
conscious behaviours
voluntary behaviours
Peripheral Nervous system
consists of the nerves located outside of the CNS
also has two branches
- Somatic nervous system
- Autonomic nervous system
PNS function
- Carries information to the cns from the body’s sensory organs (external environment)
- carries information away from the CNS to the bodys muscles, organs and glands
Somatic Nervous System
is a sub division of the PNS. Is a network of nerves that carry sensory information to the CNS and motor information away from the CNS
Sensory information
sensory information is received at sensory receptor sites (muscles, skin joints and tendons) and carried along sensory neural pathways by sensory neurons (afferent pathway)
Motor Information
motor information is carried away from the CNS through motor neural pathways to the skeletal muscles which responds to the messages from the CNS which initiate movement
Autonomic consists of
is a subdivision of the PNS and consists of
- Sympathetic
- Parasympathetic
- Enteric
Autonomic function
connects the CNS to the body’s internal organs and glands. The ANS is a self regulating system and occurs without conscious effort and is not under voluntary control. Maintains our survival
Sympathetic Nervous System
when the body comes into contact with a threat the body enhances our needs for survival by providing a response in a split second also known as the fight/flight/ freeze response
Parasympathetic nervous system
in times of minimal stress and absence of threat the Parasympathetic nervous system helps maintaining internal environment in a state of homeostasis.
how the parasympathetic and sympathetic act together?
the parasympathetic system counter balances the sympathetic system.
when the sympathetic has passed the parasympathetic system takes over and calms thes body down
Enteric Nervous System
The ENS has a two way connection to the CNS, they work together to control the digestive system
- can function independently without the brain, can carry out some digestive processes without communicating with the brain. ENS is self regulating
Neurons
neurons are basic building blocks of the NS, specialized to communicate info around the body
3 types of neurons
Sensory (afferent) neurons - body to brain
Motor (efferent) neurons - brain to skeletal muscles
Interneurons - communicate and join sensory and motor neurons
neural message
= action potential
dendrite
recieves incoming neural messages
soma
the body of the neuron, containing 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 speed of transmission
axon terminal
exit pathways for neural messages to make their way to the next neuron
terminal buttons
releases chemical substance known as neurotransmitter to a receiving neuron for communication purposes, also known as synaptic knobs
neurotransmitters
a chemical substance produced by a neuron that carries a message to other neurons or cells in muscles, glands.
neural communication
neurons communicate via a process called neurotransmission which uses electrochemical energy
process of neural transmission
1) a neural impulse (electrical energy) runs from the dendrite down the axons to the axon terminal
2) the terminal button (synaptic knobs) release a chemical substance (neurotransmitter)
3) the neurotransmitter crosses the synapse and BINDS to a receptor site (lock and key) then the message has occurred.
what is a presynaptic neuron
releases neurotransmitters from vesicles
what is a synaptic gap
where neurons communicate via electrical charge
receptor site
neurotransmitter are stored
post synaptic neuron
reuptake of neurotransmitters occur
Excitatory Neurotransmitters
increase the likelihood that neuron will fire an action potential ACTIVATION
example of excitatory neurotransmitter
Glutamate
is an excitatory nt that sends signals to cells for large brain networks (ENABLES LEARNING AND MEMORY)
Inhibitory neurotransmitter
decreases the likelihood that neurons will fire an action potential (DEACTIVATION)
Examples of inhibitory neurotransmitters
GABA ( gamma-amino-butyric acid)
blocks or inhibits brain signals
low levels of gabba = anxiety fear and stress
neurohormone
neuron in blood supply
neuromodulator
- they are chemicals that are released the same way as neurotransmitters
- neuromodulators enhance signal transmissions + impacts last longer
- can influence neurotransmitters
examples of neuromodulators
Serotonin and dopamine
Dopamine
- Is made in the susbtantia Nigra in the brain.
- Involved in motivation, drive, motor movement and reward system.
Too much dopamine = Parkinson disease
too little = associated with Schizophrenia
dopamine reward system
when experiencing something rewarding the brain responds by releasing dopamine, resulting in feelings of PLEASURE and EUPHORIA. (can lead to ADDICTION)
serotonin
- mood stabilizer
involved in wellbeing, happiness, digestion, metabolism & stress. Irregular serotonin has been associated with depression and plays a role in the SLEEP WAKE CYCLE
increase in serotonin = reduce amount of REM
neuroplasticity
is the ability of the brain to change itself as a result of experince (learning + memory, accidents + injury,)
THIS CHANGES NERUAL CONNECTIONS AND PATHWAYS
Two types of neuroplasticity
Developmental
- Brain is maturing and growing on a neural level
Adaptive
- recovery, adapting to, relearning after injury
(eg brain injury after accident)
synaptic plastcity
ability of the synapse to change in response to experience
e.g) synaptic plasticity enables change involving the strengthening or weakening of connections in neurons in the synapse
Long term Potentiation (LTP)
the increase in synaptic strength through high-frequency stimulation of a neural pathway
Long term depression (LTD)
the reduction of the efficiency of synaptic connections. Weakening of a neural pathway
Sprouting
Involves reestablishing neural connections between neurons (LTP)
Rerouting
involves reestablishing neural connections by creating alternate pathways (LTP)
Pruning
Fading/decay of weak, ineffective or unused synapses (and eliminates connections to other neurons) (LTD)
Stress
stress is a state of psychological and physiological state or tension in response to stimulus
Eustress
Good kind of stress/ enhances memory, performance, experience
Distress
Negative impact/ decrease, performance
Acute stress
a form of stress characterized by intense psychological and physiological symptoms that last for a short period of time
Chronic
a form of stress that endures for several months or longer (pressures, ongoing, demands and worries that are constant and long lasting)
Stressors
a stressor is the stimulus that prompts the stress response it can either be internal or external
Internal
a stimulus from within a persons body that prompts the stress
External
a stimulus from outside of a persons body that prompts the stress response
fight - flight - freeze
the response is more premiant during acute stress
Coritsol
is a stress hormone that acts more slowly and effects are more longer lasting, helps keep the bodying dealing with stress after adrenaline has worn off.
what cortisol affects
- Cortisol blocks the immune system
- vulnerability to heart disease
- high blood pressure
Has good short term affects but bad long term affects
HPA axis
is a complex network of hormones that is activated by stress
H = hypothalamus / fear center in the brain
P=Pituitary / hormone gland in the brain
A=Adrenaline / adrenal cortex in body release stress hormone
GBA
involves direct and indirect pathways between cognitive and emotional areas
Gut microbiota
-Living organisms that live in our GI tract and help maintain gut health and functioning
- Gut microbiota communicates with the brain through GBA, also affects mental processes and behaviours
Microbiome
is where microbiota live and can be affected by factors including diet, infection, disease and lifestyle choices
Links to stress with microbiota
stress and microbiota have bidirectional links.
Stress can disturb the balance of microbiota and can make microbiota more vulnerable to stress.
links with stress with brain and gut
brain and gut communicate through networks of neural hormones. The network and the signals within it can be disturbed when experience of stress
vagus nerve
Relays messages between the gut and brain.
Is responsible for 80/90% of info conveyed from the gut to the brain. Vagus nerve connects to every part of the GI tract
GAS Stage 1 (Alarm reaction)
when person first becomes aware of the stressor
2 subdivisions
- shock
- countershock
shock
body goes into a temporary state of shock and body ability to deal with stressor falls below normal
e.g slow heart + breathing rate
counter shock
- The sympathetic system is activated, fight/flight is activated.
- HPA releases adrenaline & cortisol into bloodstream but adrenaline is the main stress hormone in this stage
(heart +breathing rate fastens)
Stage 2 ( Resistance)
- The intense level of arousal from alarm reaction diminishes through parasympathetic system but physiological levels remain above normal.
- cortisol is the main hormone in this stage.
This levels leads to colds and headaches due to cortisol
Stage 3 exhaustion
the body has been dealing with the stressor for a prolonged time, stress hormones have been depleted and resistance to disease is weak.
The body has became vulnerable
Pros of GAS
- There is evidence of the relationship between stress and illness
- It highlights a predictable pattern that can be measured in individuals
Cons of Gas
- Research was not conducted on humans but on rats, hard to make a generalization
- Doesn’t account for individual differences and psychological factors
Pros of lazarus and folkman
- Account for individual differences in responses to similar situations in appraisal stages and why people react to the stressors
- Psych approach - acknowledges thoughts and feelings
Cons of lazarus and folkman
- Lack of empirical evidence due tp the subjective nature of the experiment
- There is often overlap between primary and secondary appraisal stages and they are less discrete and reoccur more simultaneously then the model suggests
- No bio/physical perspective
What are Approach strategies
involves behaviours that attempt to decrease the stress by addressing or finding solutions to the problem.
- healthy way of dealing with stress
What are avoidance strategies
these involve failing to engage or deal with the stress by protecting oneself from psychological distress.
- typically unhealthy way of dealing with stress
The 4 coping strategies
Resilience - our ability to bounce the following adversity
Self Efficacy - the belief in our own ability and that our actions can influence outcomes
Emotion-based-coping– Regulating your feelings and emotions to the problem instead of addressing it
Problem-based-coping – active efforts to manage stressful situations
Context-specific effectiveness
need to ensure that the coping strategy is a good fit for the situation. If it is, we call this context-specific effectiveness
coping flexibility
coping flexibility is the ability to adjust or change ones coping strategies depending on the unique and changing demands of a stressor
