Remove the brain from one side of the bisected head.
- Identify the side of the cadaver head without the falx cerebri (cerebral falx). (G 7.20A;N 102;Gl 34.13) Use this side of the head for the remainder of this Step (Substeps B-G). If the falx cerebri is split between the two sides of the head, then use scissors to remove the partial falx from one side of the head.
- (ON THE SIDE WITHOUT THE FALX) Identify the cerebellum, medulla, pons, midbrain and cerebrum (the brain rostral to the midbrain). (G 7.84D;N 105;Gl 40.19) Transect (Cut 1) the brain between the midbrain and cerebrum.
- (ON THE SIDE WITHOUT THE FALX) Use a scalpel to transect (Cut 2) the medulla where it meets the spinal cord. Elevate the brainstem and and use iris scissors to carefully cut cranial nerves XII, X, IX, VIII, VII, VI, V and III. Attempt to leave a short (2 mm) section of each nerve attached to the brainstem (it is more important to leave a section of each nerve with the cranial cavity). (G 7.28; N 113;Gl 40.19B)
- (ON THE SIDE WITHOUT THE FALX) Use a scalpel to cut the vertebral artery at the same level where you transected the medulla.
- (ON THE SIDE WITHOUT THE FALX) Use your fingers (or a blunt instrument) to free the cerebellum from the surrounding dura of the posterior cranial fossa. During this procedure you will need to tear many small veins extending from the cerebellum to the dural venous sinuses. (G 7.22;N 103;Gl 34.17) You may need to use your iris scissors to remove the tentorium cerebelli. (G 7.20;N 142;Gl 34.13) Remove the brainstem and attached cerebellum from the posterior cranial fossa. The arteries should stay with the brain and the cranial nerves should remain with the head (cranial cavity).
- (ON THE SIDE WITHOUT THE FALX) Use a scalpel to cut the optic nerve, internal carotid artery, and infundibulum (connecting the pituitary to the brain). (G 7.22;N 103)
- (ON THE SIDE WITHOUT THE FALX) Use your fingers (or a blunt instrument) to free the cerebral hemisphere from the surrounding dural structures by tearing the many cerebral veins draining into the dural venous sinuses. The brain should now be detached from the surrounding structures. Use your fingers to lift the brain from the cranial cavity.
