What is the Monro-Kellie theory?
What finally came to be known as the Monro-Kellie doctrine, or hypothesis, is that the sum of volumes of brain, CSF, and intracranial blood is constant. An increase in one should cause a decrease in one or both of the remaining two.
What are the three elements described in the Monro-Kellie doctrine?
The Monro-Kellie doctrine states that the skull is a rigid compartment and contains three components: brain, blood, and cerebrospinal fluid. If an increase occurs in the volume of one component, the volume of one or more other components must decrease, or ICP will be elevated.
What is ICP?
Intracranial pressure (ICP) is defined as the pressure within the craniospinal compartment, a closed system that comprises a fixed volume of neural tissue, blood, and cerebrospinal fluid (CSF).
What are the components of the cranium that according to Monro Kellie affect ICP?
The cranium is a rigid structure that contains three main components: brain, cerebrospinal fluid, and blood. Any increase in the volume of its contents will increase the pressure within the cranial vault. The Monroe-Kellie Doctrine states that the contents of the cranium are in a state of constant volume.
What does Cushing’s triad indicate?
What is Cushing’s triad? Cushing’s triad refers to a set of signs that are indicative of increased intracranial pressure (ICP), or increased pressure in the brain. Cushing’s triad consists of bradycardia (also known as a low heart rate), irregular respirations, and a widened pulse pressure.
Why does ICP cause bradycardia?
When arterial blood pressure exceeds the intracranial pressure, blood flow to the brain is restored. The increased arterial blood pressure caused by the CNS ischemic response stimulates the baroreceptors in the carotid bodies, thus slowing the heart rate drastically often to the point of a bradycardia.
When did burrows come up with the Monro Kellie doctrine?
1846 – Burrows introduced some changes to this hypothesis in his book On the disorders of the cerebral circulation, postulating that cerebral blood volume may vary but only to the benefit or the detriment of brain and CSF volumes Monro A. Observations on the structure and functions of the nervous system.
How does the Monro Kellie doctrine affect the brain?
An increase in one should cause a reciprocal decrease in either one or both of the remaining two. The doctrine is fundamental to our understanding of the negative effect of raised intracranial pressure on the brain.
What was the name of Kellie Monro’s book?
Monro A. Observations on the structure and functions of the nervous system. Edinburgh: William Creech; 1783. Kellie G. On Death from Cold and on Congestions of the Brain.