During the fight and flight response, elevated levels of epinephrine and norepinephrine stimulate less sensitve alpha receptors as well as beta receptors on smooth muscle of blood vessels.

Question

How does this impact blood flow?

I believe it impacts blood flow by redirecting from the GI tract and kidneys to skeletal muscle. Can someone confirm?

Answer 1

Yes that is correct. This redirects blood flow to the structures that are more important for survival/avoidance of danger or death rather than worrying about whether you can digest the sandwich you just consumed.

Answer 2

Yes, this is true.

Binding to the alpha adrenergic receptors will lead to vasoconstriction (decreased blood flow) whereas binding to the beta adrenergic receptors will lead to vasodilation (increased blood flow). Depending on the receptor type within the arterial smooth muscle of each organ, there will be a different response.

The body will redirect blood from organs that are not urgently needed (i.e. kidneys, gastrointestinal tract), to the systems that are essential for facing a threat (i.e. heart, lungs, skeletal muscles).