Editing Haemodynamic response (section)

[[File:Haemodynamic response function.svg|thumb|The canonical haemodynamic response function (HRF). The spike indicates a brief intense period of neuron stimulation, which requires increased blood and nutrient flow. As the needs of the neuronal activity are met, blood flow returns to homeostatic levels.]]

In [[hemodynamics|haemodynamics]], the body must respond to physical activities, external temperature, and other factors by [[homeostasis|homeostatically]] adjusting its [[blood flow]] to deliver nutrients such as [[oxygen]] and [[glucose]] to stressed [[tissue (biology)|tissues]] and allow them to function. '''Haemodynamic response''' ('''HR''') allows the rapid delivery of blood to active [[neuron]]al tissues. The brain consumes large amounts of energy but does not have a reservoir of stored energy substrates. Since higher processes in the [[brain]] occur almost constantly, [[cerebral blood flow]] is essential for the maintenance of [[neurons]], [[astrocytes]], and other cells of the brain. The coupling between neuronal activity and blood flow is [[neurovascular coupling]].<ref>{{Cite journal|last=Iadecola|first=Costantino|date=2017|title=The Neurovascular Unit Coming of Age: A Journey through Neurovascular Coupling in Health and Disease|journal=Neuron|language=en|volume=96|issue=1|pages=17–42|doi=10.1016/j.neuron.2017.07.030|pmc=5657612|pmid=28957666}}</ref>