The Cortex and The Brainstem

ventral lateral view of the brainstem

Project description:

A ventral-lateral view of the brain is rarely seen in textbooks and atlases. Other than its scarcity in undergraduate anatomy education, I depicted the brain from this unique perspective because, not only does this view showcase the relationship of the cranial nerves to the external features of the brainstem, it also clarifies how parts of the brainstem connect with the diencephalon and the telencephalon. I based the sketch on brain serial dissections from Grant’s museum, a Somso brain model, and a maquette made from MRI images from BodyParts3D. To enhance the interconnectedness between the subcortical structures and external macrostructures, which are essential for understanding the optic and pyramidal pathways, I removed the right occipital lobe and the insula to reveal footprints of association bundles, the projection fibers, parts of the corona radiata, and the contour of the lateral ventricle.

Process Work:

Boy oh boy. This is going to be a long one.

It all started with a very simple neuro assignment: depicting the cerebrum or the brainstem from two perspectives. Looking at the project description, I thought, what if you can do everything the project asks for in ONE illustration? 

When the weather is cold and slimy, even a 15-min walk to UofT’s anatomy museum feels far. So instead, I stayed cooped up in our Mississauga workspace and stared at some models:

SOMSO Brain model for brainstem sketch
SOMSO Brain model for brainstem sketch
Ventral lateral view of the diecephalon sketch
Ventral lateral view of the diecephalon sketch

I was happy with the concept and sketch, then I proceeded to the photoshop render. Comes the deadline of the assignment and this is what I submitted:

A post shared by Tracy Xiang (@bluberrybons) on

 

Spring critique rolls around. The more I looked at what I handed in, the more I wanted to change it. I had a better idea of how everything fits together after a semester of neuro. The direction of the corona radiata looked weird? Change it. The cerebral peduncles looked pasted on and modular? Change it. The general shading of the cortex looked too schematic? Change it. Emphasize the shading of the orbit. Clarify the structures that have been removed. 

MSC2012: Ventral Lateral view of the Diencephalon
Second re-revision of the brainstem drawing. The diencephalon focusing on the brainstem and the cranial nerves. Sketched and painted in Photoshop.

 

It was the night before the spring critique. I was reasonably content with the progress of the illustration. “Interesting. I’ve never seen a brain in this orientation before.”A faculty member commented. “Something is still off though, I need to look at more references.”

“The way you rendered the white fiber around the thalamus is interesting. Why not do the same thing for the cortex?” Another suggested.

“The optic chiasm looks weird. So does the cross-section.”

“Definitely need to look at more actual specimens.”

So I went back to Grant’s museum and focused on specimens that showed how the diencephalon is connected to the cortex. On the model, you see a vacant space for where the 4th ventricle is –– and it looks awkward as hell when you add some depth shading to it. Looking at the sketches of the human specimens, I decided that I can either render the entire internal capsule or render the basal ganglia overlapping the thalamus to avoid showing that awkward, sans-cerebral-spinal-fluid black gap.

Third round of diencephalon sketch made at the Grant's museum.
The third round of diencephalon sketch made at Grant’s museum.

I also made maquettes with sculpey polymer clay to help me draw and shade the caudate nucleus (RIP Sculpey rose). 

IMG_1620

The current render is the closest to what I had envisioned while sketching the first draft. Could it be better? Absolutely. But, for now I’m letting my brain taking a break from looking at brains. 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s