A hormone involved in regulation of BP -

Compensatory mechanisms in acute haemorrhage In acute haemorrhage there is compensatory sympathetic stimulation which causes 1) Generalized vasoconstriction with increased total peripheral resistance (TFR). 2) Increased heart rate (tachycardia). 3. Increased cardiac contractility. 4. Increased renin release causing sodium and water retention through the RAA system. 5. The shift of fluid from intracellular and interstitial space into vascular space.