Tag: dura mater
Brain covers: Journeys to the brain -1
This journey begins with a visit to the brain’s covers. Starting from the hard bony skull, another three layers inside the skull provide different kinds of protection to the brain. At the same time, they carry out various tasks.
Join this journey!
Intro: I extracted and cropped several visuals for this post on brain covers from a video clip produced by the University of Utah under the Creative Commons non-commercial use license.
The presenter who appears in the original clip is Dr. Suzanne S. Stensaas, PhD, Professor Emeritus in that University. I am greatly indebted to Dr. Suzanne S. Stensass, and her team for making this invaluable resource.And, I have also cited the link at the end of this post for the benefit of anyone interested in watching the full video.
Please note that this post contains several visuals of a brain specimen.
Our brain is a very pliable organ. Even a finger pressure can make a dent over its surface. Therefore, it needs good protection. Fortunately, very hard skull bones provide that protection. Inside the skull, three layers cover the brain. They prevent friction as well as act as a cushion. However, that is not their only job.
The outer most covering: Dura mater (“tough mother”)
The outermost cover is the thickest and the firmest of all three; hence the name: Dura mater meaning “tough mother”.
Now, look at Figure 1; the metal pointer is on this Dura mater. It’s glistening and transparent. Because of its transparency, we can see a lot of trees like branches that spread out inside the cover. In fact, these are blood vessels.
Figure 2 shows how thick and hardy the Dura mater is. Moreover, we can see the cover carries pockets. Those anchor different parts of the brain. The purpose is to keep those parts in place.
Figure 1: Dura mater with the brain (Courtesy: University of Utah)
Creative commons license
Figure 2: Dura mater after removing the brain (Courtesy: University of Utah)
Creative commons license
Other two covers
Now, we look at the two inner covers. Inside the Dura matter, the other two thinner coverings (Figures 3 and 4) spread all over the brain surface. These covers are also transparent. Unlike the outer covering, they wrap the brain surface tightly throughout all grooves and bumps of the brain surface.
Figure 3: Outer and inner brain covers
(Image source: University of Utah); creative commons license
Figure 4: Innermost brain cover and brain surface (Image source: University of Utah);creative commons license
In-between the two layers harbor a fluid – named cerebrospinal fluid (in short CSF). Not only that, small branches of arteries traverse throughout the layers. They carry oxygen and food to the neuron forest and other structures.
Why should we know about this?
Why should we know this information? This is the reason; when a small branch of artery bursts or damages blood leaks out and fills the space between the two covers. Depending on the volume, the leaked blood builds pressure on the pliable brain surface. As a result, it may exert pressure over neurons in that area. This undue pressure disrupts its job. Sometimes this pressure may even cause death. It has to be stopped.
“Visuals drawn from the NeuroLogic Exam and PediNeuroLogic Exam websites are used by permission of Paul D. Larsen, M.D., University of Nebraska Medical Center and Suzanne S. Stensaas, Ph.D., University of Utah School of Medicine.
Additional materials were drawn from resources provided by Alejandro Stern, Stern Foundation, Buenos Aires, Argentina; Kathleen Digre, M.D., University of Utah; and Daniel Jacobson, M.D., Marshfield Clinic, Wisconsin. The movies are licensed under a Creative Commons Attribution-NonCommerical-ShareAlike License“.
The information source: I extracted and cropped above stills from a video presentation presented by Dr Suzanne S. Stensaas, PhD, Professor Emeritus in the Department of Neurobiology and Anatomy of the University of Utah School of Medicine in 2012. I have no formal affiliation with the University. However, I found this valuable resource which is licensed under Creative Commons Non- Commercial use.
As per the Creative Commons regulations, I am giving due prominence to the resource and its link for the readers to gain more knowledge of the topics I cover in this website.
The website details are as follows:
Neuroanatomy Video Lab: Brain Dissections by Suzanne S. Stensaas, PhD, Professor Emeritus
Department of Neurobiology and Anatomy
University of Utah School of Medicine
https://library.med.utah.edu/neurologicexam/html/brain-dissections.html#10
