Parts of the sylvian fissure

The sylvian fissure divides the frontal lobe and parietal lobe above from the temporal lobe below.

Sylvian fissure has two parts.

1. Superficial part

2. Deep part

The superficial part is the part seen to the exterior

The convexity face of the Sylvian fi ssure displays fi ve major arms (rami) that help to define the surface anatomy of the convexity.

The long nearly horizontal portion of the sylvian fi ssure is the posterior horizontal ramus (PHR).

At its anterior end, the anterior horizontal ramus (AH) and the anterior ascending (AA) ramus arise together in a “V” or “Y” confi guration.

At its posterior end, the prominent posterior ascending (PA) ramus and the small posterior descending (PD) ramus branch outward in a “T” or “fi shtail” confi guration.

The anterior subcentral sulcus ( Single arrow) and the posterior subcentral sulcus (Double arrow) form two minor arms that extend superiorly into the frontoparietal operculum to delimit the subcentral gyrus.

One or multiple transverse temporal sulci (Triple arrows) extend inferiorly into the temporal lobe in relation to the transverse temporal gyrus of Heschl.

The deep part has 2 compartments

1. The Spheniodal or Anterior compartment and

2. Operculo insular or Posterior compartment