How many lobes does the brain have?
- Four, in most textbooks: frontal, parietal, temporal and occipital. Each hemisphere has its own set, so a whole brain has two of each. [1][2]
- Five or six, in some sources: they add the insula (the insular lobe) and the limbic lobe. Others count the insula as part of the temporal lobe instead. [1][8]
- The limbic lobe is the odd one out: it is an arc of cortex on the inner face of each hemisphere made of parts of the frontal, parietal and temporal lobes, chiefly the cingulate gyrus and the parahippocampal gyrus, so counting it means counting that cortex twice. [9]
- The cerebellum is also divided into lobes (anterior, posterior and flocculonodular), but “the lobes of the brain” normally means only those of the cerebrum. [1][10]
Where one lobe ends and the next begins
- The central sulcus runs from the top of the head down each side and separates the frontal lobe in front from the parietal lobe behind; it also divides the primary motor cortex from the primary somatosensory cortex. [11][2]
- The lateral (Sylvian) sulcus, the most prominent groove on each hemisphere, separates the frontal and parietal lobes above from the temporal lobe below; the insula lies deep inside it. [12][2]
- The parieto-occipital sulcus separates the parietal lobe from the occipital lobe. It is mostly on the inner (medial) face of the hemisphere; only a small notch of it reaches the outer surface. [13][2]
- On the outer surface no single deep groove divides the occipital lobe from the parietal and temporal lobes, so that edge is drawn by convention; this model shows it where the BodyParts3D atlas draws it. [2][14]
- The longitudinal fissure, the deep midline cleft, separates the left lobes from the right ones. [4]
- Names: the frontal, parietal, temporal and occipital lobes are named after the skull bones that cover them: the frontal, parietal, temporal and occipital bones. [3][7][4]
How big each lobe is on this model
The box each left-side lobe fits in on this one model, not its volume or surface area [14]. Real brains vary.
| Lobe | Front to back | Top to bottom | Side to side |
|---|---|---|---|
| Frontal lobe | 130 mm | 97 mm | 63 mm |
| Parietal lobe | 94 mm | 84 mm | 69 mm |
| Temporal lobe | 114 mm | 60 mm | 61 mm |
| Occipital lobe | 63 mm | 54 mm | 44 mm |
| Insula | 52 mm | 35 mm | 19 mm |
On this model each lobe is lit as the atlas’s gyri for it, so the temporal lobe’s set includes the parahippocampal gyrus on its underside, which sources that count a limbic lobe would put there instead. The cingulate gyrus is left unlit because it belongs to no lobe on this page. [14]