Constriction occurs when the muscular walls of blood vessels contract.
Constriction raises blood pressure.
Blood pressure rises when muscular walls of blood vessels conract.
what happens when muscular walls of blood vessels contract?

[1] digestion
[2] weathering
[3] blood pressure rises
[4] Dehydration
[5] recovery time from fatigue
[6] rapid expansion
[7] major threat to health
[8] respiration