QuestionSBA
QuestionChoice
Adrenaline causes vasoconstriction - when the body is in 'fight or flight', triggered by adrenaline, vasoconstriction keeps most of the body's blood close to the major organs, ensuring they are perfused first. This also minimises blood loss should that happen.
10001950
d
Decreased adrenaline
QuestionChoice
Vasopressin, otherwise known as anti-diuretic hormone (ADH), is a potent vasoconstriction.

Increased vasopressin causes increased water retention in the body, raising the blood pressure, and causing vasoconstriction at the same time. This follows the Law of LaPlace - the pressure is inversely related to artery radius - when artery pressure increases, the radius must decrease.

Decreased vasopressin, therefore, has the opposite effect - vasodilation.
10001949
c
Decreased vasopressin
QuestionChoice
Increased oxygen usage leads to vasodilation. Increased oxygen consumption indicates an increased metabolic need in the body - this can happen, for example, when someone is exercising.

Cells need more oxygen when this occurs, therefore, vasodilation occurs to supply all cells with enough oxygen - this is why our bodies get warmer when we exercise.
10001951
e
Increased oxygen usage
QuestionChoice
Increased blood temperature causes vasodilation. Think about having a warm shower - it would make your skin warmer from vasodilation. The opposite, such as putting an ice pack on your ankle after an injury would cause vasoconstriction, decreasing blood flow to that area.
10001948
b
Increased blood temperature
QuestionChoice
Increased angiotensin II would lead to vasoconstriction. Angiotensin II is responsible for increasing blood pressure - when blood pressure rises, vasoconstriction follows. This is due to the Law of Laplace - the blood pressure in a vessel is inversely related to vessel radius - when artery pressure increases, the radius must decrease.
10001947
a
Increased Angiotensin II
Concept
Chapter
2693
3993
Vasoconstriction
Topic
134
Cardiology
12936
Which of the following would lead to vasoconstriction?
a