Pathophysilogy Of Primary Hypertension

PATHOPHYSIOLOGY OF PRIMARY (ESSENTIAL) HYPERTENSION 1.) Baroreceptor (major stretch receptor) activation

2.) Chemoreceptor reflex activation by decrease O2 & pH

3.) Humoral (RAAS)

Vasomotor center activation

Cardioregulatory center stimulation

Abnormality in the transport of Na in renal tubules

Vasoconstriction Increase peripheral resistance

Prolonged and sustained increase in BP

Increase venous return Increase blood volume

Increase cardiac output

Kidney produces renin Increase in heart rate and stroke volume

Above normal increase of blood pressure

Alteration in chemoreceptor autoregulation Chronic hypertension

Increase peripheral vascular resistance

Rennin catalyzes Angitensinogen Angiotensinogen convert angiotensin I to II

Sympathetic stimulation

Baroreceptors continue to “reset” Arterial baroreceptors become desensitized

Increase heart pumping action

Increase blood volume

Angiotensin II converted to III

Increase BP/ HPN Vasoconstriction Inhibition of sodium excretion

Angiotensin I and II stimulates adrenal cortex Adrenal cortex release aldosterone

Sodium reabsorption and potassium excretion

Increase blood volume H2O retention