Superior temporal gyrus (Lateral part)
The exposed outer face of the superior temporal gyrus, the top convolution of the temporal lobe just below the lateral sulcus.
At a glance
- English
- Superior temporal gyrus (Lateral part)
- System
- Brain and spinal cord
- Region
- Head
- Side
- Paired, left and right
About the superior temporal gyrus (lateral part)
The superior temporal gyrus is the uppermost convolution of the temporal lobe, lying above the ear on the side of the head. It runs back from the temporal pole, below and parallel to the lateral sulcus, and is separated from the middle temporal gyrus below by the superior temporal sulcus. Behind, it has no sharp end; an imaginary line drawn up from the preoccipital notch to meet the lateral sulcus is used as its limit, and its back part curves up into the supramarginal gyrus of the parietal lobe. The gyrus has two surfaces: an upper one hidden inside the lateral sulcus, carrying the transverse temporal gyri and the planum temporale, and the lateral surface visible from the side. This page shows that lateral part.
The lateral surface holds auditory association cortex, mainly Brodmann area 22, which surrounds the primary auditory cortex of the transverse gyri. Its front part leads into the cortex of the temporal pole, and its back part, especially on the left, forms a large share of Wernicke's area. Fibres of the arcuate fasciculus link this posterior region with Broca's area in the frontal lobe.
The lateral gyrus analyses complex sounds. Some areas respond to combinations of frequencies, others to changes in pitch or loudness over time, and a region along its length responds selectively to voices. In the dominant hemisphere, usually the left, the posterior part is essential for understanding spoken words. The gyrus also takes part in social perception, in reading emotion from faces and voices, and in picking out one speaker against background noise.
Damage to the posterior left superior temporal gyrus, usually from a stroke in the inferior division of the middle cerebral artery, causes Wernicke (receptive) aphasia: fluent but empty speech and poor comprehension. Structural changes in the gyrus have been reported in schizophrenia, and it has been linked with auditory hallucinations.
Function and supply
- Function
- Auditory association cortex that analyses complex sounds and voices; on the dominant side its back part is essential for understanding speech.
- Blood supply
- Temporal branches of the middle cerebral artery.
Anthromica
See the superior temporal gyrus (lateral part) 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.
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