Parieto-occipital sulcus
Sulcus parietooccipitalis
A deep cleft, mostly on the inner face of the hemisphere, that separates the parietal lobe from the occipital lobe.
At a glance
- English
- Parieto-occipital sulcus
- Latin (TA2)
- Sulcus parietooccipitalis
- System
- Brain and spinal cord
- Region
- Head
- Side
- Paired, left and right
About the parieto-occipital sulcus
The parieto-occipital sulcus (or fissure) is one of the deep, constant grooves of the cerebral hemisphere. It divides the parietal lobe from the occipital lobe and, on the medial surface, the precuneus in front from the cuneus behind. Most of its length lies on the medial surface; only a short notch of it shows on the lateral surface.
On the medial surface it begins at the upper border of the hemisphere and runs downwards and forwards as a deep cleft. It meets the calcarine sulcus at an acute angle, below and behind the splenium, the rounded hind end of the corpus callosum. The two sulci together form a Y lying on its side, with the wedge-shaped cuneus between them. In many brains a buried gyrus lies in the depth of the sulcus, hidden by its walls.
Where it crosses onto the lateral surface it appears as a small cut in the upper border, about five centimetres forward of the occipital pole and a little over a centimetre long. On the lateral surface the line between parietal and occipital lobes is completed by an imaginary line from this notch to the preoccipital notch on the lower border.
The sulcus is a landmark rather than a functional area. The cortex in front of it, the precuneus, is part of the parietal association cortex and is active in spatial imagery, self-related thinking and the planning of actions, often together with the dorsolateral prefrontal cortex. Behind it, the cuneus contains the upper bank of the primary visual cortex. Its position also helps surgeons and radiologists find the calcarine sulcus and the visual cortex on MRI.
Function and supply
- Function
- Separates the parietal from the occipital lobe and the precuneus from the cuneus; a landmark for locating the visual cortex.
- Blood supply
- Parieto-occipital branch of the posterior cerebral artery, with the precuneal branch of the anterior cerebral artery in front.
Anthromica
See the parieto-occipital sulcus 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.
