Skin and vessels: Sympathetic, not parasymp innervation, right?

[pfaction]

Going crazy, cannot find this in my books, but know it from school. True or false?

---

Members don't see this ad.

 

[typicalindian]

Isn't it both? sympathetic works to restrict blood flow and parasympathetic will work to dilate the vessels.

 

[pfaction]

As far as I know I don't think paraNS exists in the blood vessels...and I'm doubly not sure about skin. I could google it.....

 

[typicalindian]

ohh I think I remember something from my physio course about this, let me know if this makes sense to you:

Blood vessels have inherent tone, so when sympathetic stimulation increases, they can further constrict, and when sympathetic stimulation is removed, they can relax.

 

[pfaction]

That I do know for a while since a lot of drugs act to remove that tone from the vessels. Same with the heart and paraNS: If there was no dual innervation, the heart is either on or off, no inbetween, same with vessels.

 

[MedPR]

I don't know what the MCAT rules are for this, but some vessels do have parasympathetic innervation.

http://en.wikipedia.org/wiki/Autonomic_nervous_system#Blood_vessels

 

[Charles_Carmichael]

ohh I think I remember something from my physio course about this, let me know if this makes sense to you:

Blood vessels have inherent tone, so when sympathetic stimulation increases, they can further constrict, and when sympathetic stimulation is removed, they can relax.

It's not a matter of sympathetic stimulation causes vasoconstriction while removing sympathetic stimulation causes vasodilation.

Sympathetic activity causes vasoconstriction and vasodilation depending on what adrenergic receptors (the receptors that norepi/epi bind to) are present in the vasculature in different areas of the body.

 

[typicalindian]

It's not a matter of sympathetic stimulation causes vasoconstriction while removing sympathetic stimulation causes vasodilation.

Sympathetic activity causes vasoconstriction and vasodilation depending on what adrenergic receptors (the receptors that norepi/epi bind to) are present in the vasculature in different areas of the body.

OH! Yeah yeah thank you do much! Now I remember everything about the alpha/beta 1 and 2 receptors. Can't believe I forgot about those.