Magnetic resonance imaging, also known as an MRI, allows us to look inside of the human brain to see its general layout. This technique provides images of thin cross-sections of the brain. Within these images, the different parts of the brain are shown as grey matter, white matter and dark areas of cerebrospinal fluid. You will hear a description of what each of these areas does within the Science Behind It section. In the Scan A Brain activity, there is a graphic representation of a human head in profile, looking to the right. There is a green horizontal bar running over the image of the head, which represents the MRI scanner. As the bar moves up towards the crown of the head or down towards the neck, the MRI image corresponding with that cross-section of the brain is shown to the right of the head. You will hear a description of ten sections of the brain shown as MRI images within this activity.
BRAIN TISSUE Cerebrospinal Fluid
Explore the Brain’s Basic Structure

Your delicate, spongy brain comes equipped with its own safety system. The outer ring you see in the image is the cranium. These hard skull bones protect your brain like a packing crate. Next, a three-layered membrane covers the brain. Think of the membrane as a natural bubble wrap. Finally, your brain floats in cerebrospinal fluid, a cushioning liquid that appears as the black layer inside the cranium.

An MRI (magnetic resonance imaging) scan sheds light on the brain’s general layout. Gray matter, on the outer surface, contains the cell bodies of neurons. Most thought processing takes place here. White matter, further inside, contains the neurons’ long, tail-like axons. Brain signals travel and connect through the network of axons. The dark areas in the center of the brain are filled with cerebrospinal fluid, which transports hormones and carries away waste.

Want to take a look inside the human brain?

Move the scanner control over the head and see brain images made with MRI (magnetic resonance imaging.)

You can operate the scanner control using your scroll bar, Up / Down arrows on your keyboard, or by clicking and dragging the scanner control.

Want to take a look inside the human brain?

Move the scanner slider to see brain images made with MRI (magnetic resonance imaging.)

You can operate the scanner control by clicking and dragging it.

To make a brain image larger on your screen, double tap it to view expanded image.