Tentorium Cerebelli

The tentorium cerebelli or just tentorium is an important structure because of its location, and anatomical relationships. The tentorium supports the occipital lobes of the cerebrum. It is attached at the sides and behind to the inner surface of the occipital bone, and in front to the petrous temporal bone. The anterior border of the tentorium is a free edge, concave in shape, and surrounding a large midline opening, the incisura tentorii or notch. The brainstem passes through this opening that is important in terms of trauma. Sudden violent movement of the brain from an impact to the head may throw the brain against the sharp free edge of the incisura, causing brain contusion or laceration. Additionally, when there is swelling or edema of the brain with increased intracranial pressure, the under side of the medial portions of the hemispheres may herniate (transtentorial herniation) through the opening of the tentorium, compressing the brain stem