Precentral sulcus in the context of Superior frontal gyrus

The inferior frontal gyrus (IFG; also gyrus frontalis inferior) is the lowest positioned gyrus of the frontal gyri, of the frontal lobe, and is part of the prefrontal cortex.

Its superior border is the inferior frontal sulcus (which divides it from the middle frontal gyrus), its inferior border is the lateral sulcus (which divides it from the superior temporal gyrus) and its posterior border is the inferior precentral sulcus. Above it is the middle frontal gyrus, behind it is the precentral gyrus.

Brodmann area 4 refers to the primary motor cortex of the human brain, one of the Brodmann areas. It is located in the posterior portion of the frontal lobe.

Brodmann area 4 is part of the precentral gyrus. The borders of this area are: the precentral sulcus in front (anteriorly), the medial longitudinal fissure at the top (medially), the central sulcus in back (posteriorly), and the lateral sulcus along the bottom (laterally).

The frontal gyri are six gyri of the frontal lobe in the brain. There are five horizontally oriented, parallel convolutions, of the frontal lobe that are aligned anterior to posterior. Three are visible on the lateral surface of the brain and two are on the inferior surface of the frontal lobe in a region called orbitofrontal cortex. The other main gyrus of the frontal lobe is the precentral gyrus which is vertically oriented, and runs parallel with the precentral sulcus.

The uppermost of the five gyri is the superior frontal gyrus, below this is the middle frontal gyrus, and below this is the inferior frontal gyrus. Continuing from the superior frontal gyrus on the lateral surface, into the uppermost part of the medial surface of the hemisphere is the medial frontal gyrus. The inferior frontal gyrus includes Broca's area. On the inferior or ventral surface of the frontal lobe including the orbitofrontal cortex is the orbital gyrus. This is also called the orbital gyri because it is separated into four sections or gyri: anterior, posterior, lateral, and medial. The most medial gyrus of the frontal lobes on the inferior surface of the lobe is the straight gyrus, also called the gyrus rectus. The lowest part of the inferior frontal gyrus rests on the orbital part of the frontal bone.