neuro influence 1/17 Flashcards
action SNS on heart
- increase HR,
coronary artery vasodilation (to increase HR) - increase force myocardial contraction
- increase myocardial metabolism
sympathetic influences body via what?
T1-T4upper thoracic to superior cervical chain ganglia
innervates SA node, AV node, conduction path, myocytes
action PNS on heart
- slow HR, vasocontricion (to slow HR)
- slow force myocardial contraction
- decrease myocardial metabolism
coronary artery
parasympathetic influences body via what?
CN X vagus n
cardiac plexus
innervates SA node, AV node, sparsely myocardium
NT for sympathetic stimulation?
epinephrine, norepinephrine
NT for parasympathetic stimulation?
acetycholine
where para & sympathetic control centers?
medulla oblongata
para- cardioinhibitory center
symp - cardioacceleratory center
SNS affect on skin and peripheral vasculature?
postganglionic sympathetic innervation
- vasoconstrict cutaneous arteries
- sympathetic inhibition allows vasodilation
what are drugs that increase sympathetic function?
sympathomimetics
what are drugs that decrease sympathetic function?
sympatholytics
what receptors are the main mechanism that controls heart rate?
where are they?
what reflex do they use?
baroreceptors, pressoreceptors, mechanoreceptors
in aortic arch, carotid sinus - work via vasomotor center
circulatory/baroreceptor reflex
what does the circulatory reflex cause if?
- increased BP
- PNS stimulation- decrease HR, decrease force cardiac contraction
- SNS inhibited, allow vasodilation, decrease peripheral resistance
what does the circulatory reflex cause if?
- decreased BP
- SNS stimulation- increased HR, vasodilate coronary arteries to increase HR
increase BP, vasocontrict peripheral blood vessels
what does the circulatory reflex cause if?
- increased R atrial pressure
reflex accelerate HR
what are chemoreceptors sensitive to change?
where are they?
change in blood chemicals - O2, CO2, lactic acid
carotid body- bifurcation carotid arteries
chemoreceptors action if
- increased CO2
- decreased pH (increased lactic acid)
increase HR
chemoreceptors action if
- decreased O2
increase HR
chemoreceptors cause what
- increased O2
decrease HR
how does HR change?
-increased body temp
HR increase
how does HR change?
-decreased body temp
HR decrease
what term - increase concentration potassium?
affect on heart?
hyperkalemia
decrease HR, decrease force contraction
ECG: wide PR interval and QRS, tall T waves
what ion change?
hyperkalemia
what term - decrease concentration potassium?
affect on heart?
hypokalemia
arryhythmias, may progress to ventricular fibrillation
what term - increase concentration calcium?
affect on heart?
hypercalcemia
increase heart actions
