Brain’s collaterals: Journeys to the brain-6

Brain's internal collateral system

Brain’s internal collateral systems: (Image source: Stroke Journal)

You must have read my post on Brain’s blood flow: Journeys to the brain- 4. It is not the only oxygen and food supply route to the brain; we have our brain’s alternate collateral supply system too – just in case. This brain’s collaterals are a very recent finding. However, we have been known about the primary source of these collaterals: the Circle of Willis.

Circle of Willis

The yellow-colored circle is the “Circle of Willis” (Figure 1). It is well connected to the red-colored main supply routes.

Figure 1: Intracranial vessels.
Yellow: Circle of Willis (adapted from the Stroke Guidelines of the University Hospital of Bern 2017, under the creative commons license.

Other collaterals

In addition to the Circle of Willis, we own a secondary mechanism too. In other words, our brain has an alternate mechanism to keep brain cells alive whenever its blood supply is interrupted. Figure s summarises that channel system. David Liebeskind published an article about this system in the Stroke journal in 2003. According to him, these collaterals divert blood into affected regions. I have cited the url link below for those who are interested in reading about this topic more.

Figure 2: Brain’s internal collateral systems: (Image source: Stroke Journal)

These collaterals, as we can easily understand, should be vital to minimizing the damage that may cause by an ischemic stroke. The author says that the extent of these collateral systems determines the clinical outcome.

The collaterals keep the neurons and their supportive cells alive until a rescue operation from us arrives. Hence, the extent of collaterals at the “war zone” is vital according to Jung Simon et al. (2017).


Liebeskind D.S. (2003). Collateral Circulation. Stroke. 34:2279–2284.

Jung S, Wiest R, Gralla J, McKinley R, Mattle H, Liebeskind D. Relevance of the cerebral collateral circulation in ischaemic stroke: time is brain, but collaterals set the pace. Swiss Med Wkly. 2017;147:w14538. Published 2017 Dec 11. doi:10.4414/smw.2017.14538

Author: Prasantha De Silva

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