2. Arterial Blood Pressure ABP (mmHg) = cardiac output (ml/min) x total peripheral resistance (mmHg/ml/min) CO = stroke volume (ml) x heart rate (c/min)

3. Factors affecting B.P 1. Blood volume ( B.V B.P ) 2. Kidney (B.V RAS) 3. Reflexes 4. Blood vessels 5. Elasticity ( age B.P) 6. Blood viscosity. ( B.visc B.P) 7. Heart ( HR BP)

4. Kidney ABP renal perfusion. + Mechanoreceptors in afferent arterioles. + Renin release from Juxtaglomerular cells. + conversion of Angio I to Angio II.

6. Baroreceptors Baroreceptors are mechanoreceptors – sensitive to changes in pressure or stretch located within the walls of the carotid sinus and the aorctic arch Carotid sinus – (changes in arterial pressure) - afferent IX. cranial nerve n. glossopharyngeus Aorctic arch – (increase in arterial pressure) X. cranial nerve n. vagus cardiovascular vasomotor centers in the brain stem Baroreflex - fast regulation – via changes in he output of sympathetic and parasympathetic NS

10. Brain stem cardiovascular centers Localized in reticular formation of medulla and lower 1/3 of the pons Information from IX. and X. nerves is integrated in nucleus tractus solitarius and redirected to Cardiac decelerator center – PNS – n. vagus – SA node – decrease heart rate Cardiac accelerator center – SNS – SA node (increase heart rate, conduction velocity through the AV node, contractility) Vasoconstrictor center – SNS – vasoconstriction of arterioles and venules

11. increase in ABP decreased sympathetic outflow decrease of heart rate increased parasymp. outflow stimulation of NTS activation of baroreceptors increase firing rate in IX., X. vasodilatation decrease of heart rate contractility increased activity of NA decreased activity CAC decreased activity VC CAC - cardiac accelerator center, VC – vasoconstrictor center cardiac decelerator center

12. Sympathetic drugs 1. NE and E: high affinity B1-R and low affininty to α1- R. ( increase BP). And + of B2-R (vasodilation) 2. Dobutamine (act through D1 and D2 ) leads to increase BP.

13. Sympathatic antagonist Beta-blockers (e.g propranolol) block B1 and B2 leads to decrease BP.

14. Parasympathetic Ach: decresae HR and BP through 1. - of NE relase. 2. Production of NO.

15. Parasympathetic antagonist Atropine: block parasympathetic R and increase BP

16. Local anesthetics Procaineamide Lidocaine.

17. Others Ca2++. Ca2+ channels blockers: Verapamil. Digoxin.