Vasovagal fainting or syncope

A. True  Due to cerebral ischaemia caused by the abrupt fall in arterial pressure.

B. False  Increased vagal activity slows the heart and reduces cardiac output.

C. True  This vasodilation reduces peripheral resistance.

D. True  Because of gravity, pressure in cerebral arteries is lower when standing than when lying down.

E. False  The skin vasoconstriction in cold environments raises peripheral resistance