increased total peripheral resistance (vasoconstriction) due to reflex increases in sympathetic vasomotor drive.

increased cardiac output due to salt and water retention by the kidney.

increased cardiac output due to the actions of hormones on heart rate and cardiac contractility

autoregulation of blood flow

Ventral tegmental area

Rostral ventrolateral medulla

Area postrema

Nucleus ambiguus

When the diameter of the vessel is doubled

When haematocrit decreases from 40% to 20%

When vessel length is halved

When the pressure difference between each end of the blood vessel is halved.

Higher stroke volume and higher cardiac output

Higher stroke volume and lower cardiac output

Lower stroke volume and higher cardiac output

Lower stroke volume and lower cardiac output

60

30

20

cardiac output/total peripheral resistance

diastolic pressure + 1/3 pulse pressure

diastolic pressure plus 1/3 systolic pressure

total peripheral resistance X stroke volume