What are the in the brain surface?

Both fissures and sulci? Or only sulci? I am confused.

The brains surface has both fissures/sulci and gyri/ridges which make up the cortex/bark/surface of the brain. Typically the cortex contains the cell bodies of the neurons.

Are sulci and fissures valleys in the brain surface? Or only sulci?

In the brain, you can find both fissures and sulci on the surface. Fissures are deep grooves that divide the brain into major lobes or hemispheres. On the other hand, sulci are shallow grooves that separate the gyri, which are the ridges or bumps on the brain's surface.

To understand this concept more clearly, let's consider an example. The most prominent fissure in the brain is the longitudinal fissure, which separates the left and right hemispheres. This fissure extends from the front (anterior) to the back (posterior) of the brain. It is the deep groove that creates the distinction between the two hemispheres.

Additionally, sulci can be found within each hemisphere of the brain. These shallow grooves give the brain its characteristic wrinkled appearance. The purpose of the sulci and gyri is to increase the surface area of the brain, allowing for more efficient neural connections and processing.

So, to sum up, both fissures and sulci are present on the brain's surface. Fissures are deep grooves that divide the brain, while sulci are shallow grooves that separate the gyri within each hemisphere.