Dominant Tone Flashcards
dominant tone
means that branch of ANS (para of sympathetic) innervating that organ is dominant or more active
hearts dominant tone
parasympathetic (except in ventricles)
heart parasympathetic stimulation
muscarinic agonist; ACh–> M2 to decrease heart rate and atrioventricular conduction
heart sympathetic stimulation
B1 agonists; NE, Epi –> B1+B2 to increase heart rate, AV conduction, and contractibility
B receptor blockers (HEART)
widely used to decrease heart rate, AV conduction and contractibility
B receptor agonists useful to treat.. (HEART)
cardinogenic shock (inadequate blood flow due to dysfunction of ventricles) to increase heart rate and contractility
muscarinic receptor blockers useful to treat… (HEART)
bradycardia(abnormally slow heart rate)
blood vessels dominant tone
sympathetic
most blood vessels do NOT have … innervation
cholinergic
blood vessels parasympathetic stimulation
muscarinic agonists; ACh –> M3 on the endothelium for vasodilation (decrease blood pressure)
blood vessels sympathetic stimulation
a1 agonists; NE,Epi –> a1 for contraction (increase vascular resistance, and blood pressure)
skeletal muscles, pulmonary, abdominal viscera, renal and coronary vessels have …. which cause VASODILATION
B2 receptors
kidney dominant tone
sympathetic
There is no … innervation of the kidney
cholinergic
kidney sympathetic stimulation
B1 agonists; NE,Epi –> B1 causing increase renin secretion (increasing angiotensin and BP)
urinary bladder dominant tone
parasympathetic (detrusor muscle)
bladder parasympathetic stimulation
muscarinic agonist; ACh –> M3, M2 causing detrusor contraction and sphincter relaxation (empty bladder)
bladder sympathetic stimulation
B2/B3 agonists; NE –> B3 to relax detrusor muscle
or
NE–> a1 to contract sphincter (prevent bladder emptying)
muscarinic receptor blockers useful to treat.. (BLADDER)
urinary incontinence (involuntary urination)
benign prostatic hypertrophy
enlarged prostate constricts neck of bladder causing retention (no effect on detrusor)
how to treat benign prostatic hypertrophy
a1 receptor blocker used to relax external sphincter and help micturition
tracheal and bronchial parasympathetic stimulation
muscarinic agonists; ACh–> M2M3 to contract bronchial smooth muscles and increase secretion
tracheal and bronchial sympathetic stimulation
B2 agonists; albuterol, Epi –> B2 to RELAX bronchial smooth muscle (bronchodilators)
limitation to B2 agonists (T+B)
desensitization upon frequent repeated use
non-selective B blockers (T+B)
contract the bronchial muscle
first choice to treat asthma: B2 agonists or Muscarinic blockers?
B2 agonists
muscarinic blockers (T+B)
relax bronchial muscle and used to treat asthma and COPD (chronic obstructive pulmonary disease)
salivary and parotid glands dominant tone
parasympathetic