Q______the heart is slow if you ain't in love - miracoli

[ArchivalUser]

@fmg8, what is your definitive answer? Can you please try to explain?

[ArchivalUser]

I would say E, because as a ganglionic blocker mecamylamine would decrease the predominant parasympathetic tone of the heart (tachy.) and the sympathetic tone of the vasculature (lower BP). Meca. WAS used as an anti-hypertensive, but that's no longer the case and it is reserved for research purposes.

[ArchivalUser]

@fmg8, nice!
For Q2 the answer is E Tachycardia
A ganglionic blocker blocks the effect of the PREDOMINANT ANS TONE. So you have to know the predominant ANS tone in the organs.

In the heart the predominant tone is PARASYMPATHETIC
-A resting heart rate is normally slower than the intrinsic firing rate of the SA node because of control by the predominant parasympathetic tone.
-A DENERVATED (transplanted)HEART --> intrinsic firing rate of the SA node
-Ganglionic block--> Tachycardia

In the IRIS & CILIARY MUSCLE, the predominant tone is PARASYMPATHETIC. So the effect of a ganglionic blocker is mydriasis and cycloplegia

here is a table that shows the PREDOMINANT ANS TONE and the effect of a ganglionic blocker.

-SITE__________PREDOMINANT TONE____________EFFECT OF GANGLIONIC BLOCKADE
-Arterioles_______Sympathetic (adrenergic)_______Vasodilation; increased peripheral blood flow; hypotension
-Veins__________Sympathetic (adrenergic)_________Dilation: peripheral pooling of blood; decreased venous return; decreased cardiac output
-Heart_____________Parasympathetic (cholinergic)________________Tachycardia
-Iris_______________Parasympathetic (cholinergic)______________Mydriasis
-Ciliary muscle______Parasympathetic (cholinergic)______________Cycloplegia—focus to far vision
-GI tract____________Parasympathetic (cholinergic)______________Reduced tone and motility; constipation; decreased gastric and pancreatic secretions
-Urinary bladder__________Parasympathetic (cholinergic)__________Urinary retention
-Salivary glands______________Parasympathetic (cholinergic)______________Xerostomia
-Sweat glands______________Sympathetic (cholinergic)______________Anhidrosis
-Genital tract______________Sympathetic and parasympathetic______________Decreased stimulation

[ArchivalUser]

Thank you for the Q and explanation

[ArchivalUser]

Thanks!!!!