Brain+Dissection+Guide

Procedure 1. Review the glossary provided at end of the dissection guide. 2. Place the brain on a dissecting tray 3.Observe the dura master, or outer menings,if they are present and were not removed prior to preservation. 4. Identify the cerebrum. On the cerebral suface, observe the grooves knoen as sulci. 5.Located the four lobes of the cerebrum.At the anterior portion of the brain is the frontal lobe, which controls motor function. Dosal to this lobe is the partietal lobe, which recives and process somatic sensory information. 6. Locate the cerebellum,which is inferior to the occipital lobe of the cerebrum. The cerebellum has an outer cortex and is folded. It is incompletely divied b a dosal central ride caled the vermis. The crebellum contaols muscls coordination. 7. Place the brain on the disecting tray,ventral surface up. Located the foolowing structures: medulla,pons,brain stem,and spinal cords. 8. The cranial nerves and pituitary were cut when the brain was removed from the skull.You should be able to identify the olfactory bulb, which lies bellow the frontal lobe of the cerebrum. Identify the optic chiasma. This x-shaped structure is formed by the crossover of the right and left optic nerves. 9. Place the brain on a dissecting tray,dosal side up. Using your finger, gently widen the medical longitudinal fissure. Insert a scalpel into the fissure and cut through the corpus callosum connection the two cerebral hemispheres. 10. Each hemisphere contains a lateral ventricel, referred to as the first and second ventricles. The lateral ventricles can be located by removing the septum pellucidum.The septum pellucidum is a thin, transparent membrane located inferior to the corpus callosum on each hemisphere. 11. Located the third and fourth ventricles. The fourth ventricel connect to the central canal of the spinal cord. It is also conected to the third ventricles by a cerebral aqueduct. Examine each ventraicl and try to identify the choriod plexus, which produces cerebrospinal fluid. 12. With the cut surface facing up, located the following parts: thalamus,hypothalamus,pineal body, pons, and medulla. 13. Obseve the cut surface of the cerebellum. In the medical setion, the white matter of the cerebellum forms a branches, treelike pattern called the arbor vitae.Tyr to identy this pattern. 14. Located the midbrain region, locationed inferiorly between the thalamus and pons. This area contains important nerve tracts. 15. Make a cross section through a cerebral hemisphere just anterior to the thalamus. Examine the cross section and identify the inner white matter and outer gray matter. 16. Remove the cerebellum and the remainder of the cerebral hemisphere by the dissecting away everything dorsal to the floor of the lateral ventrtical. 17. Remove the hippocampus to located the remainder of the thalamus. 18. Once you have obsevered all the structturs of the brain, dispose of the sepcimen in accodinace with the local guideslines and your teacher instructurction.