Inferior parietal lobule

Inferior parietal lobule
File:Gray726 inferior parietal lobule.png Lateral surface of left cerebral hemisphere, viewed from the side. (Inferior parietal lobule is shown in orange.)
File:Gray725 inferior parietal lobule.png Lateral surface of left cerebral hemisphere, viewed from above. (Inferior parietal lobule shown in orange.)
Details
Latin	Lobulus parietalis inferior
Part of	Parietal lobe
Identifiers
NeuroNames	hier-89
NeuroLex ID	inferior parietal lobule
TA
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	{{#property:P1402}}
Anatomical terms of neuroanatomy [[[d:|edit on Wikidata]]]

The inferior parietal lobule (subparietal district) lies below the horizontal portion of the intraparietal sulcus, and behind the lower part of the postcentral sulcus. Also known as Geschwind’s territory after Norman Geschwind, an American neurologist, who in the early 1960s foresaw its importance.

Structure

It is divided from before backward into two gyri:

• One, the supramarginal gyrus, arches over the upturned end of the lateral fissure; it is continuous in front with the postcentral gyrus, and behind with the superior temporal gyrus.
• The second, the angular gyrus, arches over the posterior end of the superior temporal sulcus, behind which it is continuous with the middle temporal gyrus.

Function

Inferior parietal lobule has been involved in the perception of emotions in facial stimuli, and interpretation of sensory information. The Inferior parietal lobule is concerned with language, mathematical operations, and body image, particularly the supramarginal gyrus and the angular gyrus.

Clinical significance

Destruction to the inferior parietal lobule of the dominant hemisphere results in Gerstmann's syndrome: right-to-left confusion, finger agnosia, dysgraphia and dyslexia, dyscalculia, contralateral hemianopia, or lower quadrantanopia. Destruction to the inferior parietal lobule of the non-dominant hemisphere results in topographic memory loss, anosognosia, construction apraxia, dressing apraxia, contralateral sensory neglect, contralateral hemianopia, or lower quadrantanopia.

In other animals

Functional imaging experiments suggest that the left anterior supramarginal gyrus (aSMG) of the human inferior parietal lobule exhibits an evolved specialization related to tool use. It is not currently known if this functional specialization is unique to humans as complementary experiments have only been performed with macaque monkeys and not apes. The habitual use of tools by chimpanzees makes the uniqueness of the human aSMG an open question as its function may have evolved prior to the split from our last common ancestor.

Additional images

Animation. Inferior parietal lobule is shown in red. Animation. Inferior parietal lobule is shown in red.  Lateral view of a human brain, main gyri labeled.  Cerebrum. Lateral view. Deep dissection.  Cerebrum. Lateral view. Deep dissection.  Cerebrum. Lateral view. Deep dissection.

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)