Step 1 - Dissection of the Cranial Cavity

Preparation:  It is best to review parts of the cranium on a skull prior to the dissection. Most of the cadavers have their brains removed, which means that many of the dural reflections have been cut. Occasionally there are cadavers that will have the brain and the cranium untouched. In these cases, the brain and cranium can be exposed and a more detailed dissection is possible if the brain is adequately preserved. Be sure to enlist the help of one of the instructors if the brain is still located in the cranium of your cadaver.

1. Remove the skull cap carefully to expose the cranial cavity as seen in this dissection. Sometimes you will have to carefully blunt dissect the dura mater away from the skull cap leaving as much of the dura as possible attached to the underlying skull cavity. Identify the dural reflections that remain such as the falx cerebri and tentorium cerebelli. Identify other dural specializations such as the falx cerebelli and the diaphragma sellae.
   NOTE: The tentorium cerebelli attachs to the bones anteriorly to form the tentorial incisure which can severe the brain stem during severe trauma.

2. Use your scalpel to open and demonstrate the dural venous sinuses including the superior and inferior sagittal sinuses, the transverse sinus, the sigmoid sinuses, the straight sinus, and the cavernous sinus. There are other small sinuses that will be difficult to identify clearly. These include the occipital, superior and inferior petrosal and the sphenoparietal sinuses.

3. You may wish to review the sinuses at this time.