Middle frontal gyrus 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 6 (BA6) is part of the frontal cortex in the human brain. It is one of the Brodmann areas. Situated just anterior to the primary motor cortex (BA4), it is composed of the premotor cortex and, medially, the supplementary motor area (SMA). This large area of the frontal cortex is believed to play a role in planning complex, coordinated movements.

Brodmann area 6 is also called agranular frontal area 6 in humans because it lacks an internal granular cortical layer (layer IV). It is a subdivision of the cytoarchitecturally defined precentral region of cerebral cortex. In the human brain, it is located on the portions of the precentral gyrus that are not occupied by Brodmann area 4; furthermore, BA6 extends onto the caudal portions of the superior frontal and middle frontal gyri. It extends from the cingulate sulcus on the medial aspect of the hemisphere to the lateral sulcus on the lateral aspect. It is bounded rostrally by the granular frontal region and caudally by the gigantopyramidal area 4 (Brodmann, 1909).

Brodmann area 46, or BA46, is part of the frontal cortex in the human brain. It is between BA10 and BA45.

BA46 is known as middle frontal area 46. In the human brain it occupies approximately the middle third of the middle frontal gyrus and the middle portion of the inferior frontal gyrus. Brodmann area 46 roughly corresponds with the dorsolateral prefrontal cortex (DLPFC), although the borders of area 46 are based on cytoarchitecture rather than function. The DLPFC also encompasses part of granular frontal area 9, directly adjacent on the dorsal surface of the cortex.

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.

The inferior frontal sulcus is a sulcus between the middle frontal gyrus and the inferior frontal gyrus.

The precentral sulcus is a part of the human brain that lies parallel to, and in front of, the central sulcus. A sulcus is one of the prominent grooves on the surface of the human brain.

The precentral sulcus divides the inferior, middle and superior frontal gyri from the precentral gyrus. In most brains, the precentral sulcus is divided into two parts: the inferior precentral sulcus and the superior precentral sulcus. However, the precentral sulcus may sometimes be divided into three parts or form one continuous sulcus.