Emergency Medical Technician (EMT) Practice Test

How does increased CO2 levels affect intracranial pressure?

1. decreased blood flow

2. cerebral vessels constrict

3. increased blood flow

4. cerebral vessels dilate

The correct answer is: increased blood flow

Increased levels of carbon dioxide (CO2) in the blood lead to a physiological response known as hypercapnia. When CO2 levels rise, it stimulates vasodilation of the cerebral blood vessels, which allows for increased blood flow to the brain. This response occurs because elevated CO2 causes the blood vessels to relax and widen, increasing circulation to the brain tissue. As a consequence of this vasodilation and the increased blood flow, intracranial pressure can rise. The increase in volume of blood within the cranial cavity can contribute to elevated intracranial pressure, which can be a critical condition requiring medical intervention. Understanding this relationship is vital for EMTs and healthcare providers, as managing CO2 levels and monitoring intracranial pressure are essential in conditions such as traumatic brain injury or stroke.