pcvt- nervous system effect UPDATED ACTUAL Questions
and CORRECT Answers
when needed the autonomic nervous system plays role in adjusting
what does autonomic nervous system adjust when HR (heart rate) and strength of contraction
needed
types of nervous systems sympathetic and parasympathetic
SA nodes receives impulses from both nervous systems (sympathetic and parasympathetic) in
different ways
sympathetic is activated that causes release of catecholamines (neurotransmitter) from nerve endings (ganglion) in
heart
sympathetic effect HR increases (ex: exercising; increases demand for increased circulation)
catecholamines work on receptors of calcium channels (opens up channels)
more calcium in the cells lower threshold potential (positive added to really low negative)
more calcium in the cells increases calcium for more contractility
catecholamines makes it fire faster
stimulation of sympathetic system sees an increase in heart rate and contraction strength
if sympathetic nervous system is overstimulated faster heart rates of >100 occur (tachycardia)
what are common catecholeamines epinephrine, norepinephrine, isoproterenol
what does epinephrin do helps increase HR and contraction strength
catecholeamines are used to increase HR and contraction strength
parasympathetic nervous system- nerves get to sa vagus nerve
node from
acetylcholine is released from a portion of vagus nerve
acetylcholine has effect on permeability of cell membrane for potassium, calcium, sodium
more potassium going out than normal so cell negative (sodium and calcium closed); sa node has hard time getting to
becomes more charged threshold and depolarizing
what does sa node having hard time getting charged low HR
and depolarizing result in
, acetylcholine release- acetylcholine inhibits sa node activity=slow HR
sympathetic increases HR
parasympathetic decreases HR
autonomic nervous system is a combination of sympathetic and parasympathetic and adjusts accordingly
brachycardia slow HR
when does SA node increase stress (can be emotional or physical) known as fight or flight
normal HR 60-80
tachycardia range more than 100
bradycardia range less than 60
what can make HR increase allergy meds, caffeine
warm weather= fast HR
cold weather= slow HR
hypokalemia low potassium
hypokalemia causes enhanced depolarization, slowed repolarization, irratibility of heart
hyperkalemia high potassium levels
hyperkalemia causes decreased and increased depolarization, increased repolarization
hypokalemia HR increases and premature beats
hyperkalemia HR decreases can cause ventricular fibrillation (right before heart stops)
hypercalcemia increased calcium outside of cell
hypercalcemia can result in increased heart irritability, fast repolarization, faster HR with premature beats
hypocalcemia decreased calcium outside of cell
hypocalcema results in prolonged repolarization, decreased HR and contraction strength, reduced
contraction
HR is controlled by autonomic nervous system
sympathetic nervouse system enhances automaticity- ability to depolarize (has to deal with HR)
parasympathetic nervous system inhibits automaticity
and CORRECT Answers
when needed the autonomic nervous system plays role in adjusting
what does autonomic nervous system adjust when HR (heart rate) and strength of contraction
needed
types of nervous systems sympathetic and parasympathetic
SA nodes receives impulses from both nervous systems (sympathetic and parasympathetic) in
different ways
sympathetic is activated that causes release of catecholamines (neurotransmitter) from nerve endings (ganglion) in
heart
sympathetic effect HR increases (ex: exercising; increases demand for increased circulation)
catecholamines work on receptors of calcium channels (opens up channels)
more calcium in the cells lower threshold potential (positive added to really low negative)
more calcium in the cells increases calcium for more contractility
catecholamines makes it fire faster
stimulation of sympathetic system sees an increase in heart rate and contraction strength
if sympathetic nervous system is overstimulated faster heart rates of >100 occur (tachycardia)
what are common catecholeamines epinephrine, norepinephrine, isoproterenol
what does epinephrin do helps increase HR and contraction strength
catecholeamines are used to increase HR and contraction strength
parasympathetic nervous system- nerves get to sa vagus nerve
node from
acetylcholine is released from a portion of vagus nerve
acetylcholine has effect on permeability of cell membrane for potassium, calcium, sodium
more potassium going out than normal so cell negative (sodium and calcium closed); sa node has hard time getting to
becomes more charged threshold and depolarizing
what does sa node having hard time getting charged low HR
and depolarizing result in
, acetylcholine release- acetylcholine inhibits sa node activity=slow HR
sympathetic increases HR
parasympathetic decreases HR
autonomic nervous system is a combination of sympathetic and parasympathetic and adjusts accordingly
brachycardia slow HR
when does SA node increase stress (can be emotional or physical) known as fight or flight
normal HR 60-80
tachycardia range more than 100
bradycardia range less than 60
what can make HR increase allergy meds, caffeine
warm weather= fast HR
cold weather= slow HR
hypokalemia low potassium
hypokalemia causes enhanced depolarization, slowed repolarization, irratibility of heart
hyperkalemia high potassium levels
hyperkalemia causes decreased and increased depolarization, increased repolarization
hypokalemia HR increases and premature beats
hyperkalemia HR decreases can cause ventricular fibrillation (right before heart stops)
hypercalcemia increased calcium outside of cell
hypercalcemia can result in increased heart irritability, fast repolarization, faster HR with premature beats
hypocalcemia decreased calcium outside of cell
hypocalcema results in prolonged repolarization, decreased HR and contraction strength, reduced
contraction
HR is controlled by autonomic nervous system
sympathetic nervouse system enhances automaticity- ability to depolarize (has to deal with HR)
parasympathetic nervous system inhibits automaticity
