Part 6: Brain and Spinal Cord

Using an isolated brain specimen, and demonstration specimens, identify the following nervous tissue structures of the brain and spinal cord. Be sure to look at these structures from dorsal, ventral, and midline views.

On the isolated brains, identify the cerebrum, brainstem, and cerebellum.

• Note that the brain is composed of a right and a left hemisphere, with the corpus callosum communicating between the two.

• Cerebrum: Two cerebral hemispheres with gyri (ridges) and sulci (grooves).

  • • Identify the frontal lobe, occipital lobe, and piriform lobe.

      • • On the ventral surface of the brain, identify the olfactory bulb of the piriform lobe, which is associated with cranial nerve I (CN I, olfactory).

• Brainstem: Observe on the ventral surface and in a midline view.

  • • Identify the diencephalon (i.e., thalamus, hypothalamus).

      • • Identify the optic chiasm, which is associated with cranial nerve II (CN II, optic).

        • Identify the hypophysis (aka pituitary gland).

    • Identify the midbrain, pons, and medulla.

• On the dorsal surface and in a midline view, identify the cerebellum, composed of two bilateral hemispheres.

On the demonstration specimens that have been cut down to show the spinal cord (including the plastinated museum specimen), identify the spinal cord, two meningeal layers (dura mater and pia mater), and spinal nerves.