The frontal lobe is the front part of each cerebral hemisphere, behind the forehead: everything ahead of the central sulcus and above the lateral (Sylvian) fissure. It is the largest of the four lobes. [1][2]
The 3D brain needs JavaScript. The text below still says where the frontal lobe is and what it does.
Slice
Opens cut by a side (sagittal) slice through the frontal lobe. Drag to turn, pinch or scroll to zoom, tap any part to name it; .
The central sulcus separates it from the parietal lobe behind it; the lateral sulcus separates it from the temporal lobe below it. [1][2]
Its outer surface has four gyri: the precentral gyrus, directly in front of the central sulcus, and three horizontal ones ahead of it, the superior, middle and inferior frontal gyri. [1]
Besides that outer (lateral) surface it has a pole at the very front, an orbital surface on its underside resting above the eye sockets, and a medial surface facing the other hemisphere. [1]
On this model the frontal lobe is lit as those four outer gyri plus the orbital gyri on its underside, which rest above the eye sockets. The atlas gives the narrow gyrus rectus along the midline of that underside no mesh of its own, so that strip shows only as the pale surface beneath. [3]
What it does
The precentral gyrus is the primary motor cortex, which controls voluntary movements of specific body parts. [2][1]
Broca’s area, the back of the inferior frontal gyrus (pars opercularis and pars triangularis, Brodmann areas 44 and 45), is linked to producing speech; it is usually on the left. [4][2]
The prefrontal cortex at its front supports executive functions such as planning, decision making and working memory. [5]
Taken as a whole it supports goal-directed behaviour and abstract mental representations. [1]
Connections
The arcuate fasciculus links Broca’s area with Wernicke’s area, which spans the region between the temporal and parietal lobes. [4][6]
The corticospinal tract starts largely in the primary motor cortex and runs down through the brainstem to the spinal cord. [7]
Its prefrontal part receives projections from the mediodorsal nucleus of the thalamus. [5]
Inside it
From back to front: Brodmann area 4 (primary motor cortex) on the precentral gyrus, area 6 (premotor cortex) just in front of it, then the prefrontal areas. [8][9]
Other names
Latin: lobus frontalis. Like the other lobes it is named after the skull bone over it, here the frontal bone. [1][10]
Size
About a third of the surface area of each hemisphere. [1]
On this model the left frontal lobe measures about 130 mm front to back, 97 mm top to bottom and 63 mm side to side (the box it fits in, not its volume); the right one is its mirror image. [3]
Centre of the left frontal lobe compared with the centre of the left parietal lobe: 73 mm further forward, 7 mm closer to the midline; 74 mm apart in a straight line. [3]
Centre of the left frontal lobe compared with the centre of the left temporal lobe: 35 mm further forward, 44 mm higher, 17 mm closer to the midline; 58 mm apart in a straight line. [3]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); real brains vary in size and shape, so its measurements describe one model, not anyone’s brain.