lecture 2 - nervous/endo/homeostasis Flashcards
3 parts of a neuron
dendrite (input)
axon (transmission)
synaptic terminals (output)
purpose of neurons
main wiring thru human body
connects with other neurons, tissues, organs and muscles
purpose of glia cells
number of functions for maintaining homeostasis and supporting neurons
are glial cells neuronal cells?
no
how do synapses communicate
through neurotransmitters
criteria for neurotransmitter
- must be made inside neuron, found in terminal button, and released into synaptic cleft upon an AP arrival
- produce an effect on postsynaptic neuron
- be deactivated rapidly
- have same effect on postsynaptic neuron when applied experimentally and naturally
what are the 2 parts of autonomic nervous system
sympathetic
parasympathetic
purpose + parts of CNS
brain and spinal cord
integrative and control centres
purpose + parts of PNS
cranial nerves and spinal nerves
communication lines between CNS and body
function of SNS
fight or flight responses
main neurotransmitters in SNS
epinephrine and norepinephrine
function of PNS
decrease whatever is increased by the SNS
main neurotransmitter in PNS
acetylcholine
define neuromodulation
chemical regulation by neurons
what do neuromodulators do
they affect synthesis, breakdown, and reuptake of neurotransmitters
they do not propagate APs
when secreted, they affect a large amount of neurons
what are the 4 main neuromodulators
norepinephrine
acetylcholine
dopamine
serotonin
feedback loops
needed for information processing
helps us balance
how does the endocrine system communicate
by using neuromodulators and hormones
biological stress
pressure or tension exerted on an object
psychological stress
state of mental/emotional strain due to demanding circumstances
define stress generally
real or interpreted threat to physiological or psychological integrity, resulting in physiological or behavioural responses
give 2 examples when stress is healthy
protects us from danger (adrenaline to run)
performance purposes (in sports)
cortisol
primary stress response hormone
regulate inflammation
influences immune cell response
has a negative feedback loop with the brain
diurnal trend of cortisol circadian rhythm
cortisol is highest in the first 30 minutes of waking
then there is a large drop
then it slowly continues to decrease until we sleep
what is the cortisol awakening response
when cortisol is highest in the morning
the HPA stress response system
hypothalamus responds to cortisol lvl in our immune system, it releases CRH, this goes in the pituitary gland, then ACTH releases and goes into adrenal gland, and finally cortisol is released in the immune system
homeostasis
regulating property of organism where stability of internal environment is actively maintained
allostasis
act of adaptive processes to restore homeostasis when presented with a challenge
promotes adaptation in aftermath of stress
allostatic load
temporal cascade of multi system dysregulations that contribute to disease trajectories
why do we measure allostatic load?
to predict morbidity and mortality
mortality
death
morbidity
disease or effects of illness
negative side effect of treatment
health of larger population
what increases in effective levels of brain activation
oxygen to brain
sensory awareness
clearer thinking
available energy
muscle strength
resistance to injury
what decreases in over activation of brain
logical thought
sensory awareness
conscious control
oxygen to brain
fine motor skills
accurate time perception
also results in fight flight or freeze
stress impacts on visual performance
decreased peripheral and depth
perceptual distortions
tunnel vision
stress impacts on motor performance
increased HR respiration
decreased fine motor skills
compromised hand eye coordination
stress impacts on cognitive performance
decreased oxygen to prefrontal cortex
decreased info retrieval and learned behaviours
describe the results of the terrorism, acute stress, and cardiovascular health study
high worriers had higher odds for heart health problems
53% increase in new cases of cardiovascular ailments at 2 and 3 years after the 9/11 attacks
describe the association of PTSD and disease among war vets in the study
those with PTSD had higher ratio of risk for diff types of illnesses compared to controls
results for the accumulated stress 9/11 study and conclusions
more repeated exposure in media led to increased PTSD symptoms and increased dissociated physical health ailments
conclusion was that repeated stressors can be just as impactful for PTSD symptom development when compared to single traumatic event
what percent of public safety personnel screen positive for more than one mental disorder
44.5%
diurnal cortisol in police study results
police officers have more life threat stress and they have higher level in cortisol
specifically, tactical officers have the most cortisol, as they have the most stressful role
state and define the 2 types of occupational stress
operational stress: the content of your job
organizational stress: the context of your job (interpersonal relations, work life balance, etc)
results from occupational stress injuries study
only organizational stress predicts mental health symptoms
results from study on impact of occupational stress on police performance
higher CAR increases odds of committing an error by 6% but only when outliers are included
heart rate variability (HRV)
how much variation there is between heartbeats
what is the HRV like in people with PTSD
they have much lower resting HRV
results of physiology and performance study on officers in the field
red line officer:
as they prepared for the call their heart rate increased
during the intense scenario his heart rate is very high, lasts for 20 mins
blue line officer:
overall has a lower heart rate throughout whole process
biofeedback
process of gaining awareness of physiological functions in ones body, using instruments allowing u to see changes
explain parasympathetic innervation
our heart and lungs are both connected to vagus nerves so if you activate one you activate the other!
vagus nerve active>PNS active>health and performance active
what is one way to override acute stress?
one breath reset technique
the pursed lips engage the PNS
result from study showing one breath reset test works
- pre and post training didnt have much of an impact, but at 6 months and 12 months, there is a decrease in time needed to return to HR
(however at 18 months it increased again) - right after training, there is a 3% drop in error rate, which is maintained till 12 months, but at 18 months the errors rise
BOTH FINDINGS SUGGEST NEW TRAINING NEEDED AT 18 MONTH POINT FOR BREATH RESET
