What is the normal cerebral blood flow (CBF) and how is it regulated? The brain receives approximately 750 ml/min of arterial blood or about 15% o...

What is the normal cerebral blood flow (CBF) and how is it regulated?

The brain receives approximately 750 ml/min of arterial blood or about 15% of the total cardiac output at rest, and has about 20% of the body's oxygen consumption.
Under normal conditions, this blood supply remains relatively constant.
The CBF is defined as the volume of blood that circulates through the cerebral circulation in a given time.
The normal CBF is 50-60 ml/100 g/min, ranging from 20 ml/100 g/min in white matter to 70 ml/100 g/min in some areas of gray matter.
The CBF is regulated by the physiological mechanism of autoregulation, which is a vascular mechanism of vasoconstriction and vasodilation, depending on the metabolic demand, sympathetic and parasympathetic innervation, and the concentration of some substances such as adenosine, nitric oxide, PaO2, and PaCO2.
Normally, autoregulation maintains the CBF normal between a mean arterial pressure (MAP) of 60 to 140 mmHg.
Patients with traumatic brain injury, cerebral ischemia, or vasodilator agents may have decreased or lost cerebral autoregulation, becoming dependent on MAP.