Broca’s area is the back part of the inferior frontal gyrus, in the frontal lobe just above the lateral (Sylvian) fissure: the pars opercularis and pars triangularis, Brodmann areas 44 and 45. It is in the dominant hemisphere, usually the left. [1]
Lit: the whole inferior frontal gyrus, on both sides. The area is part of this gyrus; its exact border is not drawn. Broca’s area is its back part, the pars opercularis and pars triangularis; the pars orbitalis in front is not part of it. [1][2]
The 3D brain needs JavaScript. The text below still says where Broca’s area is and what it does.
Slice
Opens cut by a front (coronal) slice through the inferior frontal gyrus, which holds Broca’s area. Drag to turn, pinch or scroll to zoom, tap any part to name it; .
Takes part in: speech, reading — see every part of each lit together.
Where it is
Broca’s area is made up of Brodmann area 44 (the pars opercularis) and area 45 (the pars triangularis) of the inferior frontal gyrus. [1]
Those are the back two of the gyrus’s three parts. From back to front: the pars opercularis, which overlies the insula; the pars triangularis; and the pars orbitalis (area 47), below and in front of the horizontal ramus of the lateral sulcus. [2]
The ascending ramus of the lateral sulcus separates the opercular and triangular parts, so the area straddles that small branch of the fissure. [2]
Neighbours of the gyrus that holds it: above, across the inferior frontal sulcus, the middle frontal gyrus; below, across the lateral sulcus, the superior temporal gyrus; behind, past the inferior precentral sulcus, the precentral gyrus. [2]
It is described as a region of the frontal lobe of the dominant hemisphere, usually the left. [1]
What it does
Its functions are linked to speech production; the article’s summary lists speech production, grammar, syntax, motor planning of speech, semantics and articulation. [1]
It is also involved in working memory and language comprehension; area 45 is often associated with controlled semantic retrieval and top-down processing during language comprehension. [1]
It plays a role in interpreting the actions of others. [1]
The left pars opercularis is part of the articulatory network with the premotor cortex and the front of the insula; it codes the motor programs for syllables and acts on speech through the motor cortex. [2]
Connections
The arcuate fasciculus connects Broca’s area and Wernicke’s area; the Wernicke’s area article adds that this tract is now understood to connect the posterior language regions with premotor and motor cortices rather than the two areas directly. [1][3]
Area 44 tends to receive more incoming connections from motor, somatosensory and inferior parietal regions; area 45 receives more from the prefrontal cortex. [1]
The uncinate fasciculus links the front of the superior temporal region with Broca’s area. [3]
The frontal aslant tract joins Broca’s area to the superior frontal gyrus, in both directions. [4]
Other names
Brodmann areas 44 and 45: BA44 is the pars opercularis, BA45 the pars triangularis. [1]
Broca area; named after Pierre Paul Broca, who linked language processing to the region. Areas 44 and 45 are now often included in a larger area called Broca’s region. [1]
Size
The model has no shape for Broca’s area itself, so it is not measured here. The whole left inferior frontal gyrus that holds it measures about 63 mm front to back, 60 mm top to bottom and 35 mm side to side on this model (the box it fits in, not its volume). [5]
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.