human brain The human brain is the central organ of the human nervous system, and with the spinal cord makes up the central nervous system. The brain consists of the cerebrum, the brainstem and the cerebellum. It controls most of the activities of the ...

anatomy, an operculum (Latin, meaning "little lid") (pl. opercula), may refer to the frontal, temporal, or parietal operculum, which together cover the insula as the opercula of insula. It can also refer to the occipital operculum, part of the

occipital lobe The occipital lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The name derives from its position at the back of the head, from the Latin ''ob'', "behind", and ''caput'', "head". The occipital lobe is the vi ...

. The insular lobe is a portion of the cerebral cortex that has invaginated to lie deep within the

lateral sulcus In neuroanatomy, the lateral sulcus (also called Sylvian fissure, after Franciscus Sylvius, or lateral fissure) is one of the most prominent features of the human brain. The lateral sulcus is a deep fissure in each hemisphere that separates the ...

. It sits like an island (the meaning of ''insular'') almost surrounded by the groove of the

circular sulcus The insular cortex (also insula and insular lobe) is a portion of the cerebral cortex folded deep within the lateral sulcus (the fissure separating the temporal lobe from the parietal and frontal lobes) within each hemisphere of the mammalian b ...

and covered over and obscured by the insular opercula. A part of the parietal lobe, the frontoparietal operculum, covers the upper part of the insular lobe from the front to the back. The opercula lie on the precentral and postcentral

gyri In neuroanatomy, a gyrus (pl. gyri) is a ridge on the cerebral cortex. It is generally surrounded by one or more sulci (depressions or furrows; sg. ''sulcus''). Gyri and sulci create the folded appearance of the brain in humans and other ma ...

(on either side of the central sulcus). The part of the parietal operculum that forms the ceiling of the lateral sulcus functions as the

secondary somatosensory cortex The human secondary somatosensory cortex (S2, SII) is a region of cortex in the parietal operculum on the ceiling of the lateral sulcus. Region S2 was first described by Adrian in 1940, who found that feeling in cats' feet was not only represe ...

Development

Normally, the insular opercula begin to develop between the 20th and the 22nd weeks of pregnancy. At weeks 14 to 16 of

fetal development Prenatal development () includes the development of the embryo and of the fetus during a viviparous animal's gestation. Prenatal development starts with fertilization, in the germinal stage of embryonic development, and continues in fetal devel ...

, the insula begins to

invaginate Invagination is the process of a surface folding in on itself to form a cavity, pouch or tube. In developmental biology, invagination is a mechanism that takes place during gastrulation. This mechanism or cell movement happens mostly in the vegeta ...

from the surface of the immature cerebrum of the brain, until at

full term Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ca ...

, the opercula completely cover the insula. This process is called opercularization.

Case reports

Albert Einstein's brain

Opinions differ on whether Albert Einstein’s brain possessed parietal opercula. Falk, et al. claim that the brain actually did have parietal opercula, while Witelson et al. claim that it did not. Einstein's lower parietal lobe (which is involved in mathematical thought, visuospatial cognition and imagery of movement) was 15% larger than average.Witelson's measurement
/ref> Figure 9 of Falk 2013 is a photograph of Einstein's right insula after removal of the operculum. (Falk 2013)

Notes

References

* * {{Cerebral cortex Cerebrum Albert Einstein

Development

Case reports

Albert Einstein's brain

See also

Notes

References