Liberal Arts Blog — In Search of the Best Brain Graphic Ever (Starting with the Three Big Divisions)
Liberal Arts Blog — Wednesday is the Joy of Science, Engineering, and Technology Day
Today’s Topic — In Search of the Best Brain Graphic Ever (Starting with the Three Big Divisions)
Visualization is key to memory. How to visualize the brain with all its convolutions, hemispheres, lobes, sulci, and gyri, the inner and the outer? the meninges and the amygdala? Well, let’s take our cue from Thoreau (“Simplify. simplify, simplify”) or Einstein (allegedly) “Simple, but not too simple” or me (“Simple, but complete”). Here’s my spin: the brain should not be thought of as that thing in your skull but as the entire nervous system because it is in fact continuous with it. The split between the part under the skull and the rest is to some extent arbitrary and obscures the continuity which is vital to function. The brain, to me, as it should be taught has three big divisions: the under the skull part, the spinal chord, and the peripheral nerves and should be visualized as such — something like an alien with a freaky head and creepy spine and limbs. Today a few more details on each of these three parts. Experts — please chime in. Correct, elaborate, elucidate.
THE SKULL PART: OUTER, MIDDLE, BRAIN STEM
1. I failed to find a great image on the web making the distinction between the outer (the cerebrum), the middle (everything not the cerebrum or the brain stem), and the bottom (brain stem).
2. Failure to make a simplified three part division results in total confusion on the part of the student. Trust me. I am that student.
3. Each of the three main parts of the brain can then be subdivided into no more than three subparts for a digestible, memorable teaching unit on the skull third of the brain.
NB: What are your three favorite parts or sub-parts of the skull part of the brain? Amygdala? Thalamus? Pineal gland? Details to come in future posts.
THE SPINAL CORD — FIVE MAJOR DIVISIONS, 31 SEGMENTS, THE GRAY PART, THE WHITE PART, THE LIQUID PART, THE “BUTTERFLY” AND THE MENINGES
1. How to divide up the spine upon both horizontal and vertical axes is an interesting challenge.
2. The spine for example has a white part (fatty myelin on the outside), the gray part on the inside) and the liquid part (the cerebral spinal fluid).
3. Did you know that the grey column at the center of the spine is shaped like a butterfly? I like to think of it as a little flying H sending messages from command central out to the little space ships which are our hands, feet, etc. (See graphic below.)
NB: The central gray and white matter of the cord are protected, as they under the skull, by the three-layered meninges (the dura, the pia, and the arachnoid).
THE PERIPHERAL NERVES — motor, sensory, and mixed
1. Out of each of the 31 segments emerge one pair of motor nerve roots, and one pair of sensory nerve roots.
2. “These nerve roots then merge into bilaterally symmetrical pairs of spinal nerves.”
3. “The peripheral nervous system is made of these spinal roots, nerves, and ganglia.”
NB: Ganglia are bundles of cell bodies that act as relay points analogous to anastomoses in the circulatory system.
FOOTNOTE — Please help here if you can
1. I have searched the web for a simplified version of the brain as a three part system and failed to find one.
2. If there is a talented designer out there who can generate one, please do and share.
3. My rough idea: an irregular, roundish grey blob for the part in the skull, a white line for the spine (as the pattern of white and grey is reversed there) and a third color (perhaps pink for no good reason) for the peripheral nerves emanating from the spine. But it’s better to have a reason. Suggestions most welcome.
A LINK TO THE LAST FOUR YEARS OF POSTS ORGANIZED BY THEME:
Please share the coolest thing you learned this week related to science, engineering, or technology. Or, even better, the coolest or most important thing you learned in your life related to science and engineering.
This is your chance to make someone else’s day. Or to cement in your mind something that you might otherwise forget. Or to think more deeply about something dear to your heart. Continuity is key to depth of thought.