Supramarginal gyrus
Gyrus supramarginalis
The front part of the inferior parietal lobule, a curved convolution arching over the back end of the lateral sulcus.
At a glance
- English
- Supramarginal gyrus
- Latin (TA2)
- Gyrus supramarginalis
- System
- Brain and spinal cord
- Region
- Head
- Side
- Paired, left and right
About the supramarginal gyrus
The supramarginal gyrus is a convolution of the parietal lobe that forms the front half of the inferior parietal lobule. It lies below the intraparietal sulcus and behind the lower part of the postcentral sulcus. Its distinctive feature is that it curves like a horseshoe around the upturned posterior end of the lateral sulcus, so that its front limb continues into the parietal operculum above the sulcus and its back limb runs down into the superior temporal gyrus. Behind it is the angular gyrus, which in turn arches around the end of the superior temporal sulcus.
Its cortex corresponds to Brodmann area 40. It receives touch and position signals from the somatosensory cortex in front, auditory signals from the temporal lobe below and visual signals from the occipital lobe behind, and with the angular gyrus it forms a high-level area where these senses come together. It is connected to the frontal lobe, including Broca's area, by the arcuate fasciculus and the superior longitudinal fasciculus.
As somatosensory association cortex it helps interpret touch, the position of the limbs and the feel of objects, and it is involved in recognising the postures and gestures that other people make. On the left it supports the sound structure of language: it is active when choosing between words by their sounds and in holding speech sounds briefly in mind, the phonological store of working memory. On the right it appears to help keep one's own feelings apart from those of others, allowing accurate empathy.
Damage to the left supramarginal gyrus can cause conduction aphasia, with poor repetition of words but good comprehension, as well as ideomotor apraxia, difficulty in carrying out learned skilled movements on command. Lesions on the right contribute to neglect of the left side of space and to disturbances of body awareness.
Function and supply
- Function
- Integrates touch, hearing and vision; supports body awareness, gesture recognition and the sound-based side of language and verbal working memory.
- Blood supply
- The posterior parietal branch of the middle cerebral artery.
Anthromica
See the supramarginal gyrus where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
