What is cerebral vascular resistance?

What is cerebral vascular resistance?

Cerebrovascular resistance is the ratio of cerebral perfusion pressure (Pα, the difference between mean arterial pressure and intracranial pressure) to CBF (Equation 2).

What does resistance mean in arteries?

Peripheral vascular resistance (systemic vascular resistance, SVR) is the resistance in the circulatory system that is used to create blood pressure, the flow of blood and is also a component of cardiac function. When blood vessels constrict (vasoconstriction) this leads to an increase in SVR.

How is cerebral vascular resistance measured?

Cerebrovascular resistance may be expressed as the ratio of cerebral perfusion pressure (P α ) to CBF (P α /CBF), where Pα = MAP – ICP [13].

What determines vascular resistance?

Vascular resistance depends on blood flow which is divided into 2 adjacent parts : a plug flow, highly concentrated in RBCs, and a sheath flow, more fluid plasma release-cell layering. Both coexist and have different viscosities, sizes and velocity profiles in the vascular system.

What happens when vascular resistance is increased?

This increase in vascular resistance allows normal blood pressure to be maintained when cardiac output is low. Afterload is the sum of forces that oppose myocardial shortening; it is directly related to blood pressure and ventricular radius but inversely related to ventricular wall thickness.

Does vascular resistance increase blood pressure?

Blood pressure increases with increased cardiac output, peripheral vascular resistance, volume of blood, viscosity of blood and rigidity of vessel walls. Blood pressure decreases with decreased cardiac output, peripheral vascular resistance, volume of blood, viscosity of blood and elasticity of vessel walls.

What is increased cerebral vascular pressure?

Hypertension-Associated Changes in The Structure of the Cerebral Vasculature. An increase in peripheral vascular resistance is a hallmark of hypertension. Vascular resistance can be increased by reducing the lumen diameter or the number of arteries or by increasing the length of arteries.

What are the 3 factors that affect vascular resistance?

The three most important factors affecting resistance are blood viscosity, vessel length and vessel diameter and are each considered below.

What causes an increase in vascular resistance?

Hypercortisolism increases vascular resistance by increasing smooth muscle sensitivity to catecholamines and increasing production of angiotensinogen. Mineralocorticoid properties of cortisol enhance the renal resorption of sodium and secondary fluid retention, resulting in an increased vascular volume.

What causes cerebrovascular?

Cerebrovascular disease can develop from a variety of causes, including: atherosclerosis, where the arteries become narrow. thrombosis, where a blood clot creates a blockage in a blood vessel. embolic arterial blood clot, which is a blood clot in an artery of the brain.

What increases vascular resistance?

Peripheral resistance is determined by three factors: Autonomic activity: sympathetic activity constricts peripheral arteries. Pharmacologic agents: vasoconstrictor drugs increase resistance while vasodilator drugs decrease it. Blood viscosity: increased viscosity increases resistance.