Directions and Planes of Section

The relative position and direction of brain structures are described with special words. For example, we can say that the frontal lobe is "rostral" to the occipital lobe.

Because the brain is a three dimensional structure, any location in the brain can be localized on three planes - the x, y and z planes. The brain is can be cut on any of these planes and are named the coronal plane, the horizontal plane or the sagittal plane.

The coronal plane, horizontal plane and sagittal plane are shown in the figure on the right. The coronal plane is also called the frontal plane. Slices of the brain taken in the coronal plane are similar to the slices from a loaf of bread. Horizontal cuts are made as if you were slicing a hamburger bun or bagel.

The sagittal plane divides the right and left side of the brain into parts. The midsagittal plane would divide the right and left sides of the brain into two equal parts, like cutting down the middle of a baked potato before you put on the toppings.

The figures below show the human brain in the three planes of section on "synthetic MR" images produced by BrainWeb:


Coronal Section

Sagittal Section

Horizontal Section

Sagittal and horizontal sections from a real MRI:

You can find photographs of coronal sections from the human brain at the Comparative Mammalian Brain Collection.

While visiting a new city or country, people often bring along a map. Neuroscientists who study the brain also use maps to identify exactly what part of the brain they are examining. These maps of the brain are called stereotaxic atlases. Just like maps, stereotaxic atlases use words to describe direction. However, instead of "north", "south", "east" and "west", the following words are used to describe direction in the brain (and other parts of the body too):

Directional Terms of the Body
DirectionDescription
Side View

Front View
VentralToward the belly (front)
DorsalToward the back
RostralToward the nose
CaudalToward the tail
SuperiorToward the top of the head/body
LateralAway from the middle
MedialToward the middle
BilateralOn both sides
IpsilateralOn the same side
ContralateralOn the opposite side

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Try it!

Do you like interactive word search puzzles? Make sure your browser is "java-enabled" and try this one:

  • Directions and Planes of Section Puzzle
  • The Washington University School of Medicine also discusses planes of section and has some excellent human brain coronal section images.

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