The sagittal suture fuses the two parietal bones together, according to InnerBody. The parietal bones in the skull, when joined together, form the sides and roof of the cranium. The sagittal suture is a dense, fibrous connective tissue joint that fuses the bones together at the top of the skull.
The anterior borders of the parietal bones meet the frontal bone along the coronal suture, and the posterior borders meet the occipital bone along the lambdoidal suture. On each side of the skull, the bottom border of each parietal bone meets the temporal bone along the squamous suture. InnerBody explains that each parietal bone contains a parietal foramen, or gap in the bone tissue where nerves and blood vessels pass through the skull.