Sheep Brain Dissection

Videos

External Brain Anatomy

1. Place the brain in the dissecting pan, dorsal surface up.
2. Observe the dura mater, or outer meninges (if present). The remaining meninges, pia mater and arachnoid mater, form a thin covering that adheres to the surface of the cerebrum. Use forceps to gently remove these layers.
3. Observe the external anatomy of the brain. Use figure 1 and identify:
1. Cerebrum
2. Cerebellum
3. Spinal cord
4. Medial longitudinal fissure
5. Right and left hemispheres
4. Examine the ventral surface of the brain. Identify the olfactory bulbs and optic nerve.
   Refer to figure 2.

Internal Brain Anatomy

1. Place the brain in the dissecting pan, dorsal surface up.
2. Using a scalpel, cut along the medial longitudinal fissure, extending the cut down the cerebellum and spinal cord to separate the brain into 2 longitudinal halves.
3. Observe the internal anatomy of the brain. Use figure 2 and identify:
1. Arbor vitae—the branching white matter in the cerebellum
2. Brain stem
3. Ventricles—cavities in the brain
4. Medulla
5. Pons
6. Pineal body
7. Thalamus
8. Corpus callosum


4. Cut a cross section of the frontal lobe and identify:
1. White matter
2. Gray matter

5. Follow all cleanup and disposal instructions.